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LIFE Project Number LIFE12 ENV/ES/000230

FINAL / Report Covering the project activities from 01/09/2013 to 30/06/2016

Reporting Date 15/09/2016

LIFE+ PROJECT NAME or Acronym LIFE CERAM - Zero waste in ceramic tile manufacture

Project Data Project location Castellón - Spain

Project start date: 01/09/2013

Project end date: 30/06/2016

Total Project duration(in months) 48 months

Total budget 799.502€

Total eligible budget 796.652€

EU contribution: 398.324€

(%) of total costs 48,9%

(%) of eligible costs 50,0%

Project Coordinator Name Beneficiary Asociación de investigación de las industrias cerámicas ITC-AICE

Contact person Dr. Fco. Javier García Ten

Postal address Campus universitario Riu Sec, Avda. De Vicente Sos Baynat s/n, Universidad Jaume I, 12006, Castellón, Spain

Telephone 34964342424

Fax: 34964342425

E-mail javier.garcia@itc.uji.es

Project Website www.lifeceram.eu

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1 List of contents

1 List of contents ........................................................................................................ 2 2 Executive Summary ................................................................................................ 3 3 Introduction ............................................................................................................. 6 4 Technical part .......................................................................................................... 7

4.1 Technical progress, per task ............................................................................... 7 4.1.1 Action A.1. State of the art in ceramic waste management at national & European level ......................................................................................................... 7 4.1.2 Action A.2. Determination of the technical and environmental key parameters of existing products for urban paving. .................................................. 7

4.1.3 Action B.1. Characterization of ceramic and non-ceramic residues. ......... 8 4.1.4 Action B.2. Body composition preparation process ................................. 13 4.1.5 Action B.3. Body and glaze compositions ............................................... 16

4.1.6 Action B.4. Industrial trials ...................................................................... 20 4.1.7 Action B.5. Technical and environmental assessment of the new product 26

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2 Executive Summary

Project objectives

The manufacturing of ceramic tiles in EU generates wastes at different stages of the production process. The estimated total amount of waste is 1,4 million tons per year. A significant percentage of these wastes can’t be recycled into the current ceramic products and processes due to the change in the behaviour of the ceramic compositions during the manufacturing process and in the tile final properties. As a result, a significant amount of waste is destined to landfills or used as very low add-valued fillers. The project's main objective is to achieve zero-waste in the manufacture of ceramic tiles. For this, we are facing two main objectives: Developing a new type of ceramic tile for outdoor application (urban paving) that

can incorporate in the body and glaze high content of ceramic waste. Other energy-intensive process wastes (from power plants or glass manufacturing) were also considered.

Designing a highly sustainable body preparation process for manufacturing the above ceramic tiles, based on dry milling technologies, capable of recycling all type of ceramic wastes.

Other objectives of the project are: Quantifying and characterizing all the wastes generated in the manufacture of

ceramic tiles and related companies (body composition suppliers, glaze producers and polishing facilities) and those from energy-intensive processes next (100 km distance) to the ceramic companies.

Designing body and glaze compositions able to recycle all types of ceramic waste. Scaling-up the laboratory results to the industry and determining the new process

variables. Disseminating the project results to the target audience (ceramic companies, public

administrations, architects, builders, general public, …)

Key deliverables

A webpage for the project activities (with the LIFE logo). Comparative report on product properties that are currently used in urban paving. Target values for the bulk and surface properties of the new product. Report with the waste characterization. Body composition to be tested and final properties obtained at lab level. Report with the new process for obtaining the body composition. Prototypes (ceramic tiles based on waste) Data sheet of the new tiles. Comparison with the current urban paving. Comparison of LCA of the new product with the current urban paving. Media and press releases with the results of LIFE CERAM project. Layman’s report Three technical publications in scientific journals and conferences. Three Project reports: Inception, midterm and final report.

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Outputs

During the project life-span several industrial trials of the new tiles have been conducted in Action B4 to demonstrate de technical and economic feasibility of the project. The amount of waste to be used in these trials is the following (considering that in the trials 2,500 m2 were produced):

Ceramic tile company (KEROS): 60 tons of waste. Glaze manufacturing company (VERNIS): 17.5 ton of waste. Machinery producer. Lower energy and water input is expected during the body

preparation in CHUMILLAS: 78% of water reduction, 74% of energy reduction and 80% reduction in CO2 emission with respect to the wet milling + spray-drying process.

The total estimated savings for producing the new tiles are 65% in water consumption, 30% in energy input and 30% in CO2 emission (Note that the drying and firing stages do not modify). According with these data the savings in the industrial production during the project life-span are: 23 m3 of water, 27,000 kWh of energy and 4.5 ton of CO2 with respect to the production of porcelain tiles. Technical part Preparatory actions of LIFE CERAM focus in the legislation that can affect the project implementation, the state of the art in ceramic waste management and the determination of the technical and environmental key parameters of existing products for urban paving. The methodology followed to conduct a benchmarking study to establish the state of the art in waste management has been in first place to develop a questionnaire to be addressed to a sample of companies from the Spanish ceramic tile manufacturers. To complete the benchmarking study, information from a voluntary agreement on waste management signed by ASCER and the environmental competent authority in Valencia region, was taken into account. Results show that only 9% of non-hazardous waste generated by manufacturers of ceramic tiles is destined for land disposal. However, this percentage seems low considering that a significant portion of red-firing scraps are not recycled or used into products with low added value. According to this data and to the Spanish annual production (420 million m2), the estimated annual generation of waste which are not valued account for 890,000 tons/year. For the determination of the technical key parameters, 1 sample of concrete tile, 3 samples of terrazzo, 1 sample of natural stone and 1 sample of porcelain tiles were selected. Bulk and surface properties to be measured and the standards to be followed were selected. Results show that the best properties were provided by porcelain tiles, followed by natural stone and finally concrete and terrazzo tiles. Based on these data target values for the new product were set up.

To conduct the LCA of existing urban paving, a literature review of Environmental Products Declarations (EDP) and LCA studies of different urban pavements: cement, terrazzo, natural stone and porcelain tiles were carried out. The results obtained will be used at the end of the project to compare LCA of the new product to the existing ones. Implementation actions of LIFE CERAM aim to characterize the wastes, design the body and glaze compositions, define the process to manufacture the body composition, conduct industrial tests and make an assessment of the technical and environmental characteristics of the new product.

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In the first action all the wastes generated in the manufacture of ceramic tiles, related companies and residues from energy-intensive processes were characterized. The characterization included, apart from physical-chemical tests, tests conducted to obtain information about the behaviour of the residues in the main ceramic process stages (milling, pressing and firing). Results showed that non ceramic residues were not suitable for the manufacturing of the new product.

Actions for designing the body composition and the manufacturing process are linked because the properties of the new body depend both on the waste mixture and on the waste particle size. Green (unfired) scraps are essential to provide the body with a suitable behaviour in the stages before firing, while polishing and glaze sludge promote sintering at high temperature, providing the tile with a low porosity. Results show that it was possible to obtain a body composition in which the content of each type of waste is similar to the waste generation. A new body composition 100% waste was obtained, but only 15% of waste was possible to include in the engobe and glaze to obtain the required properties. As the body accounts for more than 95% of the tile weight, the waste content in the new tile is over 95%.

Some pre-treatment stages, like filter-pressing for the sludge and crushing for the fired scraps, are necessary prior to the milling stages. Results show that it is convenient to obtain small particle sizes (<300 µm) for the soft residues and hammer mill is more appropriate for this purpose. The use of hard waste (fired scraps) with a coarser particle size (<1 mm) has some advantages, like milling cost reduction and low steel contamination. With respect to the granulation stage, the obtained data point out that high speed granulators provide narrower granule size distribution with high content in 300-500 µm size fraction, improving the granule flowability.

With respect to the industrial trials, waste sampling has been conducted in KEROS and the residues were sent to Ch&T for the body preparation process. The different wastes were milled separately in a pilot hammer mill. The hard wastes (fired scraps from porcelain tiles, red firing stoneware and wall tiles) were milled to obtain coarser particles sizes while the rest of residues (unfired craps, glaze and polishing sludge, etc.) were milled bellow 500 µm. Unfired scraps of the 3 types of ceramic tiles were mixed in equal parts, and the same was carried out with the fired scraps. Then, several granulations were conducted in order to adjust the granule size and moisture. The granulates were sent to KEROS for the manufacturing of the new tiles.

VERNIS made the waste sampling and prepared a frit with some of the residues that will be used as raw material for the engobe and glaze. Slips of the glaze and engobe were prepare by wet milling in a ball mill. The suspensions obtained were screened and tested in the lab prior to send them to KEROS.

KEROS conducted the trials for producing the new tiles. Some problems arose during the pressing due to the high content in small granules and the high granule moisture. Once the pressing problems were solved, several trials in the industrial kiln were carried out to define the firing temperature and firing cycle that provides the tiles with the required porosity and strength. The new tiles were glazed and decorate with contact and non-contact techniques (rotocolor and inkjet) and then they were fired and tested in the laboratory. The properties of the new tiles fit he target properties.

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3 Introduction

Environmental problem addressed. The manufacturing of ceramic tiles in EU generates wastes at different stages of the production process. The estimated total amount of waste is more than 1,4 million tons per year. The main wastes generated are green and fired scraps, and glaze sludge. A significant percentage of these wastes can’t be recycled into the current ceramic products and processes due to the change in the behaviour of the ceramic compositions during the manufacturing process and in the tile final properties. As a result, a significant amount of waste is destined to landfills or used as very low add-valued fillers.

Hypothesis to be demonstrated / verified by the project. LIFECERAM aims to demonstrate the feasibility to achieve zero-waste in the ceramic tile manufacturing process through the manufacturing of a new product based on residues and the use of existing dry milling and granulation technologies to obtain the body composition.

Description of the technical / methodological solution. The technical solution is based on two strategies:

Developing a new type of ceramic tile for outdoor application (urban paving) that can incorporate in the body and glaze high content of ceramic waste.

Designing a highly sustainable body preparation process for manufacturing the above ceramic tiles, based on dry milling and granulation technologies, capable of recycling all type of ceramic wastes.

Expected results and environmental benefits. During the project life-span several industrial trials of the new tiles have been conducted. The estimated amount of waste to be used in these trials is the following:

Ceramic tile company (KEROS): 60 tons of waste (fired and green scraps, glaze sludge and polishing sludge) for obtaining the body composition.

Glaze manufacturing company (VERNIS): 17.5 ton of waste for obtaining the glaze.

Machinery producer. Lower energy and water input is expected during the body preparation in CHUMILLAS: 78% of water reduction, 74% of energy reduction and 80% reduction in CO2 emission with respect to the wet milling + spray-drying process.

Expected longer term results. Future contribution to the development of European Union environmental policy and legislation

LIFECERAM results could provide information on the type of ceramic wastes that are being recycled currently and in a near future in order to change their classification from residue to by-product to facilitate the administrative frame on waste management and project implementation.

LIFECERAM project is aligned with the Communication of the European Commission "Towards a circular economy: a zero waste programme for Europe" that aims to establish a common and coherent EU framework to promote the circular economy. Turning Europe into a more circular economy means: boosting recycling and preventing the loss of valuable material, creating jobs and economic growth, showing how new business models, eco-design and industrial symbiosis can move us towards zero-waste and reducing greenhouse emissions and environmental impacts.

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4 Technical part

4.1 Technical progress, per task

4.1.1 Action A.1. State of the art in ceramic waste management at national &

European level

Description of the activity and outputs

Sub-task A1-1. Legislation monitoring. The main task of this sub-action has been to identify environmental legislation at European, national and regional level that would apply to the manufacture of the new ceramic product.

Main sources consulted to identify the relevant legislation have been the web sites of the competent authority on environmental issues in Valencia Region (DG Air Quality, Generalitat Valenciana), and the competent authority at national level (Ministry of Environment). In a less extent, the web site of the European Commission has also been checked. After the identification of the legal documents, a deep analysis of each document has been carried out to identify specific legal requirements that have to be met by the installation, and also the regularity and deadlines to comply with these requirements. The list of legal documents has been compiled in Deliverable DA1.2.

Sub-task A1-2. Classification and quantification of ceramic waste. The methodology followed has been in first place to develop a questionnaire to be addressed to a sample of companies from the Spanish ceramic tiles manufacturers. Due to the reduction of the budget during the revision phase, and taking into account that 95% of the national ceramic production is concentrated at the province of Castellon, it was decided to focus the study in a sample of companies with enough representativeness. The questionnaire was sent out to the members of the ASCER´s Environmental Committee, made up by technicians responsible for environmental issues in ceramic manufacturing plants. In order to complete the benchmarking study, information from a voluntary agreement on waste management signed by ASCER and the environmental competent authority in Valencia, was taken into account and analysed together with data from the questionnaires. A similar questionnaire was developed to gather information from waste generation in frit manufacturers. With all this information (Deliverable DA1.1) an estimation of the specific waste generation per type of waste has been established. 4.1.2 Action A.2. Determination of the technical and environmental key parameters

of existing products for urban paving.

Description of the activity and outputs

Sub-task A2-1. Technical key parameters. The aim of this task is to establish the technical properties required for the new product. For the attainment of this objective a comparative study of the properties of the products currently used in urban paving (terrazzo, concrete and natural stone) together with conventional porcelain tiles have been conducted. The following tasks have been carried out:

a) Selection of products and definition of test procedures. ASCER selected and got samples for their testing (1 sample of concrete tile, 3 samples of terrazzo, 1 sample of natural stone and 1 sample of porcelain tiles). ITC-AICE looked for the standards for each type of product (Table 1), defined the following bulk and surface properties to be measured and how the tests had to be performed.

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Table 1. European standards for different types of urban pavement.

Type of

product Standard

Natural stone UNE-EN 1341:2013. Slabs of natural stone for external paving. Requirements and test methods

Concrete UNE-EN 1339:2004 y UNE-EN 1339:2004/AC:2006 Concrete tiles. Specifications and test methods

Terrazzo UNE-EN 13748-2:2005 Terrazzo tiles. Part 2: Terrazzo tiles for outdoor use

Porcelain tiles UNE-EN 14411:2013 Ceramic tiles. Definitions, classification, characteristics, evaluation of conformity and marking

b) Product characterization.

All the results are included in deliverable DA2.1.

c) Definition of the properties of the new waste-based tile.

Based on the comparative study, ASCER and ITC-AICE defined the properties required for the new product. The target values for the new product are detailed in Deliverable DA2.2. Sub-task A2-2. Environmental key parameters. Those key environmental parameters that should be considered during the process design and development of “LIFE CERAM product” have been selected, in order to ensure that the new product will be at least equal or better than those competitor materials. For this purpose, several activities have been carried out:

1. Literature review of Environmental Products Declarations (EDP) and LCA studies of different urban pavements: cement, terrazzo, natural stone and porcelain tiles.

2. Assessment of relevant references applying. 3. Comparative assessment of environmental key parameters. 4. Definition of the environmental key parameters to be considered in LIFE CERAM

project. From a general perspective, all references considered are of great quality and show a proper environmental profile for those products used for urban pavement purposes, however, the different methodologies and technological and geographical scenarios complicate the comparison between them. To avoid this situation, it is recommendable to develop a life cycle assessment in the previous stages of LIFE CERAM product development and consider as reference values, those found for porcelain tiles. This assessment (Deliverable DA2.3) provided enough information to ensure that the new product is at least equal to or better than the competitor product (porcelain tiles). 4.1.3 Action B.1. Characterization of ceramic and non-ceramic residues.

Sub-task B1-1. Waste collection and homogenization

All the wastes generated in the manufacture of ceramic tiles and related companies, identified in action A1, as well as residues from energy-intensive processes (power plants and glass producers), were collected and homogenized.

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Table A1 in Annex 7.2.1 shows the waste generated by KEROS in 2012. Table A2 in Annex 7.2.1 depicts the type of ceramic residues that have been characterised and will be recycled in the project (data from 3 years are reported). These residues were collected, sorted and consequently homogenized for their characterization in ITC- AICE. The residues were classified in 4 groups:

a. Green scrap b. Glaze, frit and enamel sludge c. Fired scrap d. Aqueous suspensions

VERNIS has quantified the waste generated in its facilities during 2013 (Table A3 in Annex 7.2.1). Wastes in bold have been characterized for its recycling in the project. Some data about the evolution of ceramic waste are reported in table A4 in Annex 7.2.1. VERNIS has conducted a sampling of the ceramic waste and has homogenized these samples for their characterization. ITC-AICE has focused on the residues from energy-intensive processes (power plants and glass producers). Figure 1 represents those with installed power capacity higher than 20 MW. In this figure, the coal combustion power plants surrounded with a circle are the closest to the province of Castellón and therefore, susceptible to become suppliers of fly ashes for the new tile. Samples from these power plants (Escucha and Andorra) have been collected (being representative of different production periods for both plants).

With respect to glass producers, figure 2 represents the distribution of these companies in Spain. In this figure, the facility surrounded with a circle (AGC, located in Sagunto) is the closest to the province of Castellón.

Figure 1. Power plants with capacity higher than 20 MW. Source: Unesa. www.unesa.net/unesa/html/sabereinvestigar/mapas/centralestermicas.htm.

Figure 2. Glass producers in Spain. Source: Guide of BAT for glass producers.

Sub-task B1-2. Physical and chemical characterization Table A5, table A6 and table A7 in Annex 7.2.1 show the chemical composition of the wastes. Green and fired scraps have high content of Si and medium content of Al, Ca, Mg, Na and K, as these are the elements characteristic of the raw materials used in tile bodies. In the case of polishing sludge, together with these elements, chlorine appears as differentiator element. On the other hand, B, Zn, Zr and Ba appear as differentiator elements in glaze sludge and frit residues as they are typical elements in frits (main compound of ceramic glazes). The most different composition is the one corresponding to the dust from kiln filters, which is mainly composed of calcium fluoride and calcium carbonate. In addition, sulfur and chlorine appear because these elements are also

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present in the gaseous emissions. This sample was collected by ITC-AICE due to the fact that KEROS does not have kiln filters in its premises.

With respect to non-ceramic wastes, both glass residues present similar chemical composition, with the elements typical of flat and hollow glasses. The same thing happens to the samples of fly ashes.

Another test performed for the physical characterization of the wastes has been the fusion test, which has allowed determining the most fluxing wastes for the body composition developed in Action B3. In the following table, the characteristic temperatures obtained from the fusion test are summarized. From these data, it is clear that the most fluxing materials are the glass wastes, although glaze sludge is also quite fluxing. Table 2. Characteristic temperatures of the fluxing wastes (glaze sludge and glasses).

Characteristic temperature

(ºC) Glaze sludge Flat glass Hollow glass

Shrinkage start (TIC)

Shrinkage end (TFC)

Softening temperature (TR)

Sphere (TE)

Half-sphere (T1/2)

Fusion (TF)

800 1000 1015 1070 1170 1230

670 740 805 955

1050 1150

650 735 850

1025 1095 1175

Regarding environmental issues, the gaseous emissions of the wastes have been determined. As emissions depend on the interaction of the wastes and the matrix, this determination has been performed on mixtures of a typical body composition with the wastes that are susceptible of presenting gaseous emissions. For this purpose, the acid containing compounds S, Cl and F have been determined for all the wastes. According to chemical analysis, the wastes that are susceptible of presenting acid gaseous emissions are polishing sludge, the dust from kiln filters and the fly ashes.

The following table shows the gaseous emissions (SO2, HF and HCl) of the body composition without any waste and the three mixtures. From these results it can be concluded that the three wastes do not increase fluorine emissions in the tested percentages with respect to typical body composition but a marked increase in sulphur emissions is observed with both fly ashes and dust from kiln filters, and even a higher increase in chlorine emissions in the case of polishing sludge. Table 3. Gaseous emissions (SO2, HF and HCl) of the body composition without any waste and the three mixtures.

Sample ppm SO2 ppm HF ppm HCl

Body composition 94 221 58 90% Body composition +10% polishing sludge 90 145 471

90% Body composition +10% fly ashes 308 177 52 99.5% Body composition +0.5% dust from kiln filters 266 191 35

Sub-task B1-3. Waste behaviour in the ceramic process

The characterization consisted in determining the behaviour of the different wastes in the main process stages of the ceramic tile manufacture, pressing and firing, and their final properties (shrinkage, porosity, colour, etc.). The results obtained are summarized in table 4, in which firing behaviour is represented as water absorption at 1150 ºC. Apart from green scraps, the other wastes do not present an appropriate behaviour during the pressing stage, and low values are obtained for bulk density and dry

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mechanical strength. Regarding firing behaviour, glaze sludge and polishing sludge are the most fluxing wastes. On the contrary, wall tile scraps are highly refractory wastes at 1150 °C. The aspect of the samples fired at 1150 ºC is shown in figure 3. Table 4. Results of the characterization of the wastes.

Type of waste Dry bulk density [g/cm3]

Dry mechanical strength [kg/cm2]

Water absorption at 1150ºC [wt%]

Green scraps

Wall tiles 1.95 24 14 Floor tiles 2.00 26 2

Porcelain tiles 1.89 22 4

Fired scraps

Wall tiles 1.59 1 14 Floor tiles 1.67 1 7

Porcelain tiles 1.71 1 10 Glaze sludge 1.70 5 <0.1

Polishing sludge 1.40 7 <0.1 Flat glass 1.72 1 <0.1

Hollow glass 1.77 1 <0.1 Fly ashes from Andorra 1.49 1 21 Fly ashes from Escucha 1.34 1 19

Figure 3. Aspect of the samples obtained with the wastes fired at 1150ºC except glass wastes, that were fired at

1000ºC. Leaching tests of the fired specimens from the different wastes is the last test performed in this action. Table A8 in Annex 7.2.1 shows the elements that must be determined and their li mits for the three c lasses of wastes (ine rt wastes, non ha zardous wastes a nd hazardous wastes). Leaching phenomena depends on the interaction of the wastes and the matrix, as gaseous emissions; therefore, this determination has also been performed

Wall tiles fired scraps

Porcelain tiles fired scraps Polishing sludge

Porcelain tiles green scraps

Wall tiles green scraps

Floor tiles green scraps

Floor tiles fired scraps

Flat glass Hollow glass Fly ashes from Andorra

Glaze sludge

Fly ashes from Escucha

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on mixtures of the body composition used for the determination of gaseous emissions with the wastes that are susceptible of presenting leaching phenomena. Table 5 shows the results obtained in the leaching tests. All the elements present lower concentrations than the limits for inert wastes in all the mixtures, except the mixture with polishing waste that contains in the leachate a concentration of Pb higher than the limit for inert wastes. Table 5. Results obtained in the leaching tests.

Element

(mg·kg-1)

90%Body

composition

+10% polishing

sludge

99.5%Body

composition

+0.5% dust

from kiln filters

90%Body

composition

+10% glaze

sludge

90%Body

composition

+10% Fly

ashes

90%Body

composition

+10%

hollow glass

As <0.1 <0.1 <0.1 <0.1 <0.1 Ba <1 <1 <1 <1 <1 Cd <0.04 <0.04 <0.04 <0.04 <0.04-

Crtotal <0.5 <0.5 <0.5 <0.5 <0.5 Mo <0.5 <0.5 <0.5 <0.5 <0.5 Ni <0.4 <0.4 <0.4 <0.4 <0.4 Pb 0.9 <0.5 <0.5 <0.5 <0.5 Sb <0.06 <0.06 <0.06 <0.06 <0.06 Se <0.1 <0.1 <0.1 <0.1 <0.1 Zn <1 <1 <1 <1 <1 Cl- 23 2 6 4 4

SO42- 32 24 22 123 25

With regard to the wastes generated in manufacturing frits and glazes, the results of the determination of the chemical composition are detailed in table A9 of Annex 7.2.1 and the results of dilatometric analysis in table A10 of the same annex. This information has been used in action B3 for the formulation of the frit, engobe and glaze compositions.

Sub-task B1-4. Analysis of the results

For the development of the body composition, the characterization of the ceramic wastes has shown that fired scraps present an inadequate behaviour in the pressing stage and demand high firing temperatures to achieve low water absorptions. The use of green scraps and fluxing waste such as glaze sludge, is necessary to obtain a suitable body composition. The non-ceramic wastes characterized have not been considered adequate for different reasons. In the case of fly ashes, the main reasons are their bad behaviour in the pressing stage and their refractoriness. In the case of glass residues, although they are highly fluxing wastes, they need intensive milling to develop this fluxing behaviour and as the glass particles are very hard, this milling would imply high processing cost. For the development of the engobe and glaze compositions, the non-ceramic wastes have not been used by VERNIS as the objective is to maximise the use of their own wastes and they can provide soluble salts that would affect to the quality of the glaze. Together with their wastes, the engobe and glaze compositions require some raw materials in order to achieve an adequate behaviour in the glazing operation and the intended properties for each composition. The required raw materials were clays, china clays, dolomites, zircon, feldspar, etc.

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4.1.4 Action B.2. Body composition preparation process

Description of the activity and outputs

The aim of Action B2 is to design a new manufacturing process, based on existing dry milling and granulation technologies, for the preparation of the body composition.

Sub-task B2-1. Studying the waste pre-treatment

a) Waste considered in LIFE CERAM

a.1) Ceramic wastes Green scraps. These residues are formed by unfired materials including dust from the vacuum extraction systems and broken tiles. Figure 4 show the appearance of the green scraps.

Figure 4. Container with green scraps.

Figure 5. Facility to storage the glaze sludge

Glaze sludge. It is formed by the sludge obtained in the glaze sieving and in the cleaning of the glaze mills and glaze lines. Figure 5 shows the facility for the storage of the glaze sludge.

Fired scraps. Fired materials generated in the firing and sorting stages. It includes broken tiles and tiles with a very low quality that prevents their sale to the customers.

Polishing sludge. Generated in the operations of cutting and polishing.

Dust from the kiln filters.

a.2) Non-ceramic waste

Fly ash from power plants. They are composed of glass powder and residues from coal combustion. Figure 6 shows the appearance of these residues.

Recycled glass waste. Among the different types of recycled glass, the most suitable for incorporation into the body is hollow glass from containers (Figure 7).

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Figure 6. Fly ash from coal power plant Figure 7. Hollow glass

b) Pre-treatment to be carried out for each residue.

Table A11 in Annex 7.2.1 depicts some of the waste characteristics and the pre-treatment to be carried out before the milling stage. Sub-task B2-2. Definition of the type of milling In this task different types of dry grinding have been tested to determine which is the most suitable for each type of the waste. Since the composition is based on green and fired scraps, assays were performed using these two types of waste as representative of soft and hard wastes. The types of milling studied were as follows:

Green scraps: Hammer mill and Pendulum mill. Fired scraps: Hammer mill and Disc mill.

The following tests have been conducted: electrical energy consumption and particle size of the milled wastes. From this information the most appropriate mill has been selected for each waste. Deliverable DB2-1 describes in more detail the experimental process.

Table A12 in Annex 7.2.1 includes the results. From these results graphs have been drawn which summarises the data about energy consumption (without feeding and in standard operation) and particle size obtained (Figure 8 and Figure 9). The following conclusions for soft and hard wastes can be extracted: For milling soft materials at intermediate particle sizes (200-300 microns sieve cut)

it is advisable the use of a hammer mill, whereas when finer sizes are required (<100 microns) the pendulum mill is more efficient.

Hard wastes: if hard waste has to be milled at high particle size (<1.0 mm) is more advisable to use the hammer mill for its greater effectiveness (ratio size / cost).

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0

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80

90

Hammer mill

200 m

Hammer mill

500 m

Pendular roller mill

High Intensity

grinding

Pendular roller mill

Low Intensity

grinding

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sum

ptio

n

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Rej

ect (

%)

Consumption non feeding (kW·h/h)Specific Consumption (kW·h/Tn)Reject on 100 µm (%)Reject on 180 µm (%)

m m

Figure 8. Green scraps. Energy consumption and particle

size obtained.

0

10

20

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Hammer mill

500 m

Hammer mill

1000 m

Disc mill

500 m

Disc mill

1000 m

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ect (

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Consumption non feeding (kW·h/h)Specific Consumption (kW·h/Tn)Reject on 100 µm (%)Reject on 500 µm (%)

m m m m Figure 9. Fired scraps. Energy consumption and particle size obtained.

Sub-task B2-3. Granulation In this task two types of granulators have been tested to determine which type is the more suitable for the granulation of the body composition. Deliverable DB2-1 describes the types of granulators tested. For conducting the tests, a waste composition (50% green scraps and 50% fired scraps) was granulated with different operating variables. An image of the granules is shown in the following figures.

Figure 10. Images of the granules obtained. Left: granulator 1, centre: granulator 2 at 210 r.p.m. right: granulator 2 at

380 r.p.m

The granules and compacts obtained were characterized. Deliverable DB2-1 describes the experimental procedure used and the obtained results. A summary of the results is included in Table A13 of Annex 7.2.1. figure 11 and figure 12 show the main results. It is more appropriate to use the granulator 1 due to the granule size distribution obtained (main fraction between 300-500 µm and narrow distribution).

0

20

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100

120

140

Granulator 1

4800 rpm

Granulator 2

210 rpm

Granulator 2

380 rpm

Con

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ptio

n

Consumption non feeding (kW·h/h)

Specific Consumption (kW·h/Tn)

m m Figure 11. Electrical input during granulation.

0

10

20

30

40

50

Granulator 1

4800 rpm

Granulator 2

210 rpm

Granulator 2

380 rpm

Rej

ect (

%)

< 125 µm125 - 200 µm200 - 300 µm300 - 500 µm500 - 710 µm> 710 µm

m m Figure 12. Granule size distribution.

Lay out of the body preparation process

According to the characteristics of the wastes and the milling and granulation tests conducted at lab scale, the lay-out of the body preparation process is the following:

16

Green scraps

Dust from cleaning system

Glaze sludge Fired scrapsPolishing

sludge

Dust from

Kiln filters

Grinding

Filterpressing

Proportioning

Drying

GrindingFilterpressing

High intensity

granulation

Product

Hammer mill

<300 µm

Drying

Hammer

mill

<1.0 mm

Proportioning

Drying

Green scraps

Dust from cleaning system

4.1.5 Action B.3. Body and glaze compositions

Description of the activity and outputs

The target of this action is the development of body and glaze compositions with high content of waste that provide the tiles with the required bulk and superficial properties for outdoor applications and with a suitable behaviour in the whole manufacturing process. The following sub-tasks were programmed in this action: Sub-task B3-1. Design of the body composition Green and fired scraps have been the basis of all the compositions tested as these are the wastes that are generated in higher amounts. Deliverable DB3-1 describes the experimental procedure used and the results obtained. The initial formulation was a mixture of 50% of fired scraps and 50% of green scraps, but as it can be observed in Figure A1 in Annex 7.2.1, it requires very high temperatures in order to achieve a low water absorption (3%). In order to reduce the firing temperature, new compositions were prepared which incorporate glaze sludge, polishing sludge and dust from the kiln filters. Table A18 in Annex 7.2.1 shows the new formulations.

The pressing conditions and the firing behaviour of these compositions are detailed in Table A19, A20, A21, A22 and A23 in Annex 7.2.1 and in Figure 13 y Figure 14.

3

4

5

6

7

8

1120 1130 1140 1150 1160 1170 1180 1190 1200Temperature (ºC)

Line

ar s

hrin

kage

(%)

0

2

4

6

8

10

Wat

er a

bsor

ptio

n (%

)

TCr/TCd/10LP/0,5FHTCr/TCd/10LE/0,5FHTCr/TCd/10LE

L.S. W.a.

2

3

4

5

6

7

8

1120 1130 1140 1150 1160 1170 1180 1190 1200Temperature (ºC)

Line

ar s

hrin

kage

(%)

0

2

4

6

8

10

Wat

er a

bsor

ptio

n (%

)

45TCr/45TCd/10LE/0,5FH45TCr/45TCd/10LP/0,5FH45TCr/45TCd/5LE/5LP/0,5FH45TCr/45TCd/7,5LE/2,5LP/0,5FH45TCr/45TCd/7,5LE/2,5LP/0,25FH

L.S. W.a.

Figure 13. Vitrification diagrams of the formulated body compositions.

Figure 14. Vitrification diagrams of the formulated body compositions.

17

This last composition has been fully characterized, comparing its behaviour with typical industrial body compositions (floor tile and porcelain tile). Microstructural observations, leaching tests and gaseous emissions have also been performed. The results are fully detailed in the deliverable DB3.1 and summarized below.

Pressing conditions and properties of dried specimens are detailed in Table 6. The comparison with typical body compositions enables concluding that the pressing behaviour of the optimum composition is adequate. Figure 15 shows the vitrification diagram of the last composition together with typical industrial body compositions (floor tile and porcelain tile). Table 6 depicts optimum firing temperature for each composition and the properties of fired specimens and figure A2 in Annex 7.2.1 shows the microstructure of fired specimens of the optimum body composition and a floor tile composition prepared by wet milling and spray-drying (standard process used in Europe). These results together with the results from leaching tests (Table A24 in the Annex 7.2.1) and gaseous emissions (Table A25 in the Annex 7.2.1), allow to conclude that the properties and behaviour of the new composition tested is suitable for being processing in the current industrial facilities. Table 6. Pressing conditions, optimum firing temperature and properties of fired specimens of the optimum body composition as well as typical body compositions (floor tile and porcelain tile).

Composition 45TCr/45TCd/

7.5LE/2.5LP/0.25FH

Floor tile

body

Porcelain tile

body

Moisture content (%) 5.5 5.5 5.5 Pressure (kg/cm2) 250 250 350

Dry bulk density (g/cm3) 2.005 2.021 1.953 Dry mechanical strength (kg/cm2) 20 31 35

Temperature (ºC) 1163 1158 1185

Water absorption (%) 3.0 4.0 0.5

Bulk density (g/cm3) 2.355 2.322 2.382

Linear shrinkage (%) 6.5 6.2 7.3

Index of pyroplasticity (cm-1x105) 2.3 2.5 3.5

Mechanical strength (kg/cm2) 380 430 580

2

3

4

5

6

7

8

1120 1130 1140 1150 1160 1170 1180 1190 1200 1210Temperature (ºC)

Line

ar s

hrin

kage

(%)

0

2

4

6

8

10

Wat

er a

bsor

ptio

n (%

)

45TCr/45TCd/7,5LE/2,5LP/0,25FH

Floor tile

Porcelain tile

L.S. W.a.

Figure 15. Vitrification diagrams of the optimum body composition and industrial bodies.

18

Sub-task B3-2. Glaze composition Two compositions have been developed by VERNIS in the design of glazes: engobe and the glaze itself. Engobe is the interface between the body and the glaze, while the glaze is the outer layer of the tile that conveys the final appearance of the finished product. As part of the process of developing the engobe, waste material has to be fritted to prevent certain elements from being dissolved and in order to homogenise the waste. Accordingly, a mixture of sludge and frit dust, MP-RECUP, has been used to create a special frit, called FE-LIFE. Raw materials have been added to the MP-RECUP so that the oxides match a formula that has been previously tried and tested by VERNIS. FE-LIFE should be white, opaque and have a low melting point for an optimum use in the engobe. A preliminary study has been conducted to determine the maximum percentage of MP-RECUP that can be used (Table A27 and Figure A4 in Annex 7.2.1). This is achieved by melting different amounts of MP-RECUP in crucibles using a laboratory kiln (Figure A3 in Annex 7.2.1). From these results it can be concluded that FE-LIFE frit will contain 50% of recycled material, since with this value correct results are obtained with the highest possible recovery rate. Once the correct frit has been developed, it is necessary to determine the highest possible percentage that can be used in the engobe without loss of stability. To achieve a level of melting and opacity that endows the engobe with satisfactory covering power, segregated opaque white frit (FE-OP) has been added directly in the waste characterisation study (Table A28 in Annex 7.2.1). As we know that the sum of the two frits (FE-LIFE + FE-OP) must be 15%, we have attempted to use the highest possible percentage of FE-OP with respect to FE-LIFE because the use of FE-OP is more cost-effective. These results show that the optimal percentages of waste are 10% FE-LIFE and 5% FE-OP. Two engobes with different dilatometric behaviours were formulated (Table A29 in Annex 7.2.1) with a high content in waste material because studies must be conducted to determine how they couple with the body. Their coefficients of expansion are also detailed in Table A30 in Annex 7.2.1. For the study of the composition of glazes, the intention is for them to contain the highest possible proportion of each of the types of segregated frit waste: opaque frits (FE-OP), crystalline frits (FE-CR) and matt frits (FE-MA), the correct formulation being compensated with a correctly-formulated frit in order to maintain the stability of the ceramic properties (Table A31 in Annex 7.2.1). With optimum mixture of frits, two glazes with different dilatometric behaviours have been formulated (Tables A32 and A33 in Annex 7.2.1). These four products were used to make different combinations (Table A34 in Annex 7.2.1) between the engobes and the glazes with different applications (Figure 16).

19

For the final testing of the glaze coating, 10x10 cm specimens of the optimum body composition were pressed. Once glazed and fired in VERNIS with a typical firing program of floor tiles, the tiles presented a marked curvature. As this defect is usually due to a mismatch between thermal expansion of the body and the glaze, the dilatometric analysis of the optimum body composition was performed. The results, which are detailed in Table A35 in Annex 7.2.1, show that the thermal expansion of the developed body composition lies within typical values of industrial body compositions, so this should not be the cause of the curvature.

Figure 16. Laboratory trials with engobe and glaze formulations.

Then, in order to see if the cause of the curvature was an inadequate firing program in the roller kiln of VERNIS, some tiles were fired in another program, typical of wall tiles, characterized by a lower heating speed in the interval from 800ºC to 1000ºC. With this program, the tiles showed a less marked curvature. Therefore, the dimensional changes of the specimen during the firing stage were determined by dilatometric analysis from a dried specimen and compared with those from industrial floor tile and wall tile bodies. Figure A5 in Annex 7.2.1 shows that the formulated body composition has dimensional variations more similar to wall tiles bodies than to floor tile bodies, so this could be the cause of the curvature. To check this conclusion a new composition was formulated reducing the content of the green and fired scraps from wall tiles and increasing those of porcelain and floor tiles (until that moment the green and fired scraps had been a mixture of equal parts of the three types of tiles), trying to obtain dimensional changes more similar to that of a floor tile as this kind of firing program is more adequate for the achievement of the properties demanded for the urban tile. The thermal expansion of the new composition was determined (Table A35 in Annex 7.2.1), and 10x10 specimens were pressed in ITC-AICE and glazed and fired in VERNIS with typical floor tile firing program. As the tiles showed more or less the same curvature as the previous one, wall tile firing program was tested again, and the tiles showed a less marked curvature. As this new formulation still did not give good results with floor tile firing program, the previous one was considered more adequate for industrial trials in Action B4, as the green and fired scraps were more balanced and if necessary, the firing program at KEROS facilities would be adjusted to correct curvature of industrial urban tiles. Sub-task B3-3. Definition of the process variables

Deliverable DB3.2 shows a more detailed description, being the most important variables the following: • Granule moisture 5.5% • Pressing pressure 250 kg/cm2. Unfired bulk density to be achieved around 2.00 g/cm3. • Drying cycle (temperature-time). 120ºC-100 minutes. • Glazing variables:

20

Table 7.

21

Table 7. Glazing variables.

Step Process variable Value Engobe application Density (g/cm3)

Viscosity (s) Amount (g/m2)

1.80 35 445

Glazing Density (g/cm3) Viscosity (s) Amount (g/m2)

1.80 35 445

• Firing cycle. Maximum temperature 1160-1170ºC. Duration: 42-45 minutes.

4.1.6 Action B.4. Industrial trials

Description of the activity and outputs

Based on the results from the preceding actions, industrial trials were conducted by Ch&T, VERNIS and KEROS. KEROS conducted a sampling of all the wastes generated in its facility. Then, KEROS

sent all the wastes to Ch&T for the preparation of the granulate. The different wastes

were milled separately in a pilot hammer mill

figure 17. The hard wastes (fired scraps from porcelain tiles, red-firing stoneware and red-firing wall tiles) were milled with an exit screen of 1 mm, while for the soft residues (unfired craps, glaze and polishing sludge, etc.) the screen used were 500 µm. Particle size of the wastes can be observed in Figure 19.

Figure 17. Hammer mill.

Figure 18. Granulator and dryer.

22

0

10

20

30

40

50

60

70

80

90

100

> 300 m200 - 300 m100 - 200 m< 100 m

Rej

ect

(%)

Green scraps wall tile Fired scraps wall tileGreen scraps floor tile Fired scraps floor tileGreen scraps stoneware tile Fired scraps stoneware tilePolish sludge Glaze sludge

m m m m

Figure 19. Particle size of the milled wastes.

Unfired scraps of the 3 types of ceramic tiles were mixed in equal parts, and the same was carried out with the fired scraps. Then, several granulations were conducted in order to adjust the granule size and moisture. Figure 18. Granulator and dryer.Figure 18 shows the granulator used in the trials and Table 8 some of the granulate characteristics of one of the first granules obtained compared with commercial the spray-dried powders. It can be observed that the granulate presented more fines that the commercial ones what leaded to laminating problems in the first pressing test. Annex 7.2.1 includes more pictures of the industrial trials (Figures A6 to A9) and granulate data of other granulation tests (Table A38).

Table 8. Granule size distribution.

Fraction (µm) LIFECERAM Floor Tile Porcelain tile < 125

150-200 200-300 300-500 500-710

>710

22,5 15,0 17,2 21,3 10,7 13,4

7,5 15,0 26,0 36,0 11,5 4,0

3,5 10,5 27,5 46,0 9,5 2,5

During the pilot tests conducted on Ch&T some water and energy inputs were measured in order to determine the LCA and manufacturing cost of the new tiles. Figure 20 depicts the power consumption during one of the granulation test. Data were compared with those for the manufacturing of spray-dried powder that were available in ITC-AICE. Tables A14 to A17 in Annex 7.2.1 summarize the results.

23

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50 60 70 80

Time (minute)

Pow

er (W

)

Figure 20. Power consumption during the granulation tests.

The granulates were sent to KEROS for the manufacturing of the new tiles. Before the industrial tests in KEROS, the granulate were tested in the lab determining its behaviour in the pressing and firing stages. Annex 7.2.1 includes the obtained data (tables A39 to A41) and Figures A13 to A15). VERNIS conducted a sampling of all the wastes generated in its facility. The waste was conditioned by putting the sludge in deposits to dry in the sun and then homogenising the waste in a 6000 kg mixer. The product resulting from mixing these residues is called MP-RECUP. According to the findings of studies conducted in the laboratory, the FE-LIFE frit to be introduced into the engobes in this project will contain 50% of MP-RECUP. Six 2000 kg loads of FE-LIFE were melted in a rotary kiln (Figure 21), the first load being used to clean the kiln so as to prevent possible contamination from previous operations. The automatic system prepared big bags containing 1000 kg of MP-RECUP and the other 50% of compensating raw material was added from silos in the kiln section. Although the formula was correct, the homogenisation of the material inside the industrial kiln during melting was not correct, since there was part of the material that was not melted completely (Figure 22) and, as a result, there was a lack of uniformity. Therefore, the method of loading the material into the kiln was changed, as the usual one does not work for such a high percentage of recovery of solids. To solve this problem, we propose a system in which layers of 100 kg of raw material alternate with others consisting of 100 kg of MP-RECUP until a total weight of 2000 kg per load is reached. Although this is a more costly method of loading, it is expected to result in a high level of uniformity of the material. This method could be automated for production in the future.

24

Figure 21. FE-LIFE frit at the exit of the rotary kiln.

Figure 22. Unmolten material.

After changing the internal refractory lining of the kiln because of wear with cracks produced by the badly molten material and carrying out a series of adjustments with regard to temperature, gas, pressure and load in the industrial kiln, 12 tonnes were molten again ensuring the material was slowly regulated by strata in bags – 50% of recovery material together with 50% of the correct raw material – which was weighed on the kiln feed regulation system.

Figure 23. Glaze and engobe milling.

Figure 24. Glazing.

This resulted in 10,000 kg of homogeneous product, free of unmolten material, and another initial 2000 kg that were incorrect.

Since this is a test melt with waste recovery, environmental measurements had to be performed to check that the melting of the new frit was not interfering with the usual emission of gases and pollutant particles.

With the aim of determining the behaviour of the new compositions on an industrial scale, a series of pilot-scale assays were conducted, since in this kind of materials the behaviour can vary considerably depending on whether we are working under small- or large-scale conditions. Accordingly, five 150 or 100 kg loads of each of the materials were manufactured in a semi-industrial manner.

After carrying out the control tests of the laboratory-scale milling from the pre-industrial tests, those that yielded good results were applied on the laboratory test line.

25

Once correct results had been obtained in the milling on a semi-industrial scale, 10,000 kg were milled on an industrial scale. This process can result in ceramic and rheological differences in the materials, due to the increased friction and temperature in large-scale milling. Thus, three tests had to be conducted for each of the materials to adjust the rheological conditions and eliminate the occluded air that gave rise to surface defects when the material was applied on the ceramic body.

Furthermore, because the aim is to develop a floor tile for outdoor use and this requires certain anti-slip properties, 2000 kg of two GripSystem with different grips were prepared. This application makes it possible to adjust the performance in terms of the slip resistance of the surface of a floor tile so as to meet the specification requirements. Tiles incorporating this technology still feel pleasant to the touch are easy to clean and their appearance remains unaltered. By mixing the two GripSystem, we can obtain different anti-slip properties.

Before conducting the industrial trials in KEROS, some preliminary tests were carried out to know the behaviour of the new tiles in the industrial kiln. For this some tiles were fired in different kilns with different firing schedules in order to detect firing problems like cracks and deformations. Table A42 in annex 7.2.1 details the firing cycles used in this trials.

After the preliminary tests, 5 industrial trials were conducted in the facilities of KEROS. The trials consisted in 5 main steps: pressing, drying, glazing and decorating, firing and sorting. Figure 25 and Figure 26 show the pressing and glazing steps of the industrial trials.

Figure 25. Pressing.

Figure 26. Glazing.

Tables A43 to A45 in Annex 7.2.1 shows the operating variables in each trials and the main tile properties obtained. The main conclusions of each trial are the following:

Trial 1. The granulate used had a high content of fines (content<125 µm: 22.5 %) and a high moisture (9.7 %) and as a result problems of lamination during the pressing were observed (Figure 27). The firing at a maximum temperature of 1153 °C provided the tiles with a high water absorption (8.2%).

26

Trial 2. In order to solve the lamination problems, the granulate moisture were reduced to 7.2 %. As a result, the laminations problems declined but not disappeared. The water absorption values were higher than required when firing at 1153 °C.

Trial 3. An increase of the firing temperature was conducted on the same tiles of trial 2. In this trial the firing temperature was increase to 1185 °C and as a result lower water absorption was obtained (4.2%).

Trial 4. A new granulate with a lower content of fines (content<125 µm: 5.5 %) was processed. The moisture content was 6.8 % and the firing temperature was the same as the previous trial (1185 °C). No lamination problems were detected and the water absorption (2.8%) accomplished the require target (<3%). The product bending strength was the required (38 MPa) but very close to the limit (35 MPa).

Trial 5. Although the results of trial 5 fulfil the requirements defined at the beginning of the project, a last trial was conducted in order to increase the bending strength of the tiles. For this a longer firing cycles was used (60 minutes). The fired tiles shown a water absorption of 1,6% and a bending strength of 42 MPa. Some pictures of the final product can be seen in Figure 28.

Figure 27. Lamination problem due to an excess of fines and moisture.

Figure 28. Images of the final product.

27

4.1.7 Action B.5. Technical and environmental assessment of the new product

Description of the activity and outputs

Technical assessment From the technical perspective, physico-mechanical properties have been determined on the prototypes produced in the industrial trials conducted at KEROS facilities. The results obtained in this task are included in deliverable DB5.1 and DB5.3, all of them included in Annex 7.2.2. Table 9 shows the target values defined in Action A2 and the measured values. It can be observed that the new tiles accomplish the target values defined at the very beginning of the project. Table 9. Target values to be fit by the new product and measured values.

Characteristic Target value Measured value

(trial 4) Breaking load (N) EN ISO 10545-4 > 4500 6060* Bending strength (N/mm2) EN ISO 10545-4 > 35 38

Resistance to deep abrasion (mm3) EN ISO 10545-6 < 175 175

Impact resistance. Cahier CSTB 3735 Annex 6 Resist Resist

Slip resistance ENV 12633. USRV > 45 54

Frost resistance EN ISO 10545-12 Resist Resist

Water absorption, total (%) EN 13748-2 < 3 2.8 Moisture expansion (mm/m) EN ISO 10545-10 < 0,6 0,1

Thermal expansion (K-1) EN ISO 10545-8 < 9 x 10-6 6,4 x 10-6 Dirt retention Low Low

15 mm thick Environmental assessment From the environmental point of view, a life cycle assessment of the new developed product has been performed from cradle to grave, according to the standards ISO 14040: 2006 and 14044:2006, and also ISO 21930:2007, ISO 14025:2010 and EN 15804:2012. The obtained data were compared with data of current products for urban paving determined in Action A2. Results are detailed in deliverable DB5.2 A summary of the results is shown in Figure 29. The figure shows a comparison of the life-cycle environmental impacts of different urban paving systems. The scope includes the product stage (i.e. extraction of raw materials, transportation and manufacturing of the tiles). According to the results, the new ceramic tile is better in all environmental impact categories except in two: The fossil abiotic depletion (ADP-fossil): due to low energy consumption required

in the manufacturing of concrete tiles The non-fossil abiotic depletion (ADP-elements): due to the absence of glazes on

concrete tiles and natural stones

28

Figure 29. Comparison of the life-cycle environmental impacts of different urban paving systems. Scope cradle to

gate.

29

Annex 7.2.1. Technical tables

30

Table A1. Waste generated by KEROS in the manufacturing of ceramic tiles.

Stage Type of waste CER Code Amount

(Ton/year)

Processing

Oil from presses 130100 - Bags from filters 150202 - Contaminated spray-dried powder 170106 2.72 Fired scrap 101208 1,410.00

Green scrap 101201 101203 2,683.00

Glazes 101109 20.34 Frits with heavy metals 101211 Frits without heavy metals 101212 - Hazardous sludge 190205 - Non-Hazardous sludge 080202 1,188.18 Aqueous suspensions with ceramic materials 080203 6,419.18

Sorting and packaging

Plastic Packaging 150102 - Fired ceramic tiles 101208 - Paper and Carton 150101 20.10 Plastic 150102 12.26 Wood packaging waste 150103 1.62

Maintenance

Contaminated metal packaging 150110 0.06 Contaminated plastic packaging 150110 1.06 Contaminated paper packaging 150110 1.17 Water from worshop 130507 - Waxes and fats 120112 - Cutting lubricant 120109 - Used oils 130205 0.20 Antifreeze Liquid (It really is non-halogenated organic solvent) 160114 0.22

Metal Scrap 170407 3.65 Rags and absorbent 150202 0.55 Used Batteries 160601 - Oil from filters 160107 -

Aerosols 150110 160504 0.11

Rock wool from kilns 161105 - Mercury containing wastes 060404 0.10

Table A2. Evolution with time of the ceramic waste generated in the tile manufacturing.

Waste 2011 2012 2013

Amount (Ton/year) Green (unfired) scrap: Tiles Powder from the air collected systems

2,830.00 2,683.00 2,474.00

Glazes and frits with heavy metals 15.80 20.34 12.56 Aqueous sludge with ceramic material (Non-Hazardous) 1,290.00 1,188.00 1,133.00 Fired scrap (Tiles) 1,460.00 1,410.00 1,290.00 Aqueous suspensions with ceramic materials 7,360.00 6,419.00 6,101.00

31

Table A3. Waste generated by VERNIS in the manufacturing of frits and glazes in 2013.

LER Code Type of waste Amount (ton)

10 12 11 Ceramic solids 195.00 15 01 10 Plastic packaging 1.70 16 03 03 Ceramic product of date 42.00 19 08 13 Ceramic sludge 387.00 08 02 02 Sludge containing ceramic materials 60.00 15 01 11 Metal containers 0.34 15 02 02 Bag filters 0.12 15 01 10 Paper packaging 0.08 13 02 05 Used oil 0.20 20 01 21 Fluorescent tubes and lamps 0.01 16 06 01 Batteries 0.01 08 03 12 Fabrics of silk screens 0.04 15 02 02 Wipes and absorbents 0.05 08 03 99 Toner 0.01 20 01 01 Cardboard 6.72 20 01 39 Plastic 3.32 17 04 05 Metal scrap 2.50 10 12 08 Ceramic waste (after firing) 54.62 16 11 06 Refractory from kilns 22.90 16 01 03 Tires 0.20 20 03 07 Bulky waste (Mixes) 0.24 10 11 03 Fiberglass waste 0.36 10 11 12

Frit waste different from specified in code 101111 (frit

powder) 90.00

Table A4. Evolution with time of the ceramic waste generated in the frit and glaze manufacturing.

LER Code Type of waste Ton

2011 Ton

2012 Ton

2013 10 12 11 Ceramic solids 324.00 314.00 195.00 16 03 03 Ceramic product of date 47.00 73.00 42.00 19 08 13 Ceramic sludge 286.00 242.00 326.00 08 02 02 Sludge containing ceramic materials - - 60.00 10 12 08 Ceramic waste (after firing) - - 54.62 16 11 06 Refractory from kilns - - 22.90 10 11 12 Frit waste different from specify in code 101111

(frit powder) - - 90.00

32

Table A5. Chemical composition of the ceramic wastes collected by KEROS [wt%].

Type of

waste Green scrap Fired scrap Glaze

sludge Dust from

kiln filters Polishing

sludge

SiO2 Al2O3 B2O3 Fe2O3 CaO MgO Na2O K2O TiO2 ZrO2 ZnO BaO

S Cl F

LOI

63.3 16.9 0.1 3.8 3.0 1.2 1.8 2.8 0.7 0.2 0.2 0.1 - - -

6.0

67.2 17.9 0.1 4.1 3.3 1.2 1.9 3.0 0.7 0.2 0.3 0.1 - - -

0.2

58.0± 2.0 12.3± 0.7 2.6± 0.1

0.40± 0.02 9.7± 0.5

1.66± 0.08 1.98± 0.11 2.69± 0.16 0.16± 0.01 2.47± 0.13 4.09± 0.25 1.09± 0.05 0.02± 0.01 0.05± 0.01

<0.1 2.72± 0.14

1.00 0.31 0.22

<0.15 62

0.44 0.25 0.46 0.01 0.01 0.12 0.02 2.53 1.41 32.0 7.63

60.9± 2.3 15.2± 0.9

0.93± 0.08 0.84± 0.06 3.81± 0.26 3.57± 0.21 3.33± 0.19 2.48± 0.13 0.46± 0.03 0.46± 0.03 2.51± 0.15 0.65± 0.04 0.03± 0.01 0.79± 0.05

<0.1 3.90± 0.24

Table A6. Chemical composition of the wastes from energy intensive processes collected by ITC-AICE [wt%].

Type of

waste Flat glass Hollow

glass Fly ashes from the

power plant of

Andorra

Fly ashes from the

power plant of

Escucha

SiO2 Al2O3 B2O3 Fe2O3 CaO MgO Na2O K2O TiO2 ZrO2 ZnO BaO

S LOI

71.8 0.75 0.12 0.09 8.3 4.3 13.0 0.52 0.01

<0.01 <0.01

-- 0.09 0.23

71.6 1.6 0.5

0.21 9.4

2.45 13.2 0.77 0.06 0.01

<0.01 178 ppm

0.04 0.35

42.9 26.1

-- 19.6 5.19 1.27 0.23 1.28 0.91 0.03 0.03 0.07 0.13 1.45

52.4 27.5

-- 11.3 1.72 1.23 0.35 2.73 0.85

<0.01 0.02 0.02 0.14 1.55

33

Table A7. Chemical composition of the wastes from frit and glaze production collected by VERNIS [wt%].

Type of

waste Sludge containing ceramic

materials Frit powder Ceramic solids

SiO2 Al2O3 B2O3 Fe2O3 CaO MgO Na2O K2O TiO2 ZrO2 P2O5 ZnO BaO LOI

66.7 ± 3.0 15.7 ± 2.0

- 0.4 ± 0.2 4.7 ± 0.5 0.7 ± 0.3 2.7 ± 2.0 1.1 ± 0.3 0.2 ± 0.1 1.4 ± 0.4 0.2 ± 0.1 1.1 ± 0.3

- 5.1 ±3.0

60.6 ± 3.8 4.7 ± 2.5 8.0 ± 4.0 0.1 ± 0.1

12.2 ± 2.1 1.6 ± 0.5 1.0 ± 0.5 3.9 ± 0.4 0.1 ± 0.1 3.8 ± 2.0

- 4.0 ± 2.8

- -

56.8 ± 9.1 9.2 ± 5.0 4.2 ± 3.0 0.1 ± 0.1

12.0 ± 5.0 2.9 ± 2.0 2.0 ± 1.1 3.4 ± 1.0 0.1 ± 0.1 2.9 ± 2.1

- 6.6 ± 5.0 2.4 ± 2.1

- Table A8. Admissible limits for the three classes of wastes according to Directive 1999/31/CEE.

Element (mg·kg-1)

Inert wastes Non hazardous wastes Hazardous wastes

As 0.5 2 25 Ba 20 100 300 Cd 0.04 1 5 Cr total 0.5 10 70 Cu 2 50 100 Hg 0.01 0.2 2 Mo 0.5 10 30 Ni 0.4 10 40 Pb 0.5 10 50 Sb 0.06 0.7 5 Se 0.1 0.5 7 Zn 4 50 200 Chloride 800 15000 25000 Sulphate 1000 20000 50000 Table A9. Chemical analysis of the wastes from frit and glaze manufacture.

Product Waste

mixture Ceramic solids

Opaque frits Transparent frits Matt frits

SiO2 64.8 57.1 63.7 48.4 Al2O3 8.1 8.3 7.5 11.0 B2O3 6.0 6.5 2.7 1.8 CaO 8.6 0.1 0.1 0.1 MgO 1.2 10.7 13.8 12.8 Na2O 2.9 2.4 1.3 3.8 K2O 2.4 1.7 1.5 2.2 ZrO2 2.6 3.6 3.3 3.9 ZnO 2.1 0.1 0.1 0.1 BaO -- 4.8 - 3.7

Loss on

ignition 1.3 – – –

34

Table A10. Dilatometric analysis of the wastes from frit and glaze manufacture.

Product Waste mixture Ceramic solids

Opaque frits Transparent frits Matt frits

Cubic coefficient (50-300ºC)

181 190 195 215 Transformation

temperature (TT) 630 638 632 597

Softening

temperature (TR) 800 777 840 -

Table A11. Characteristics of each waste and pre-treatment to be conducted.

Waste Appearance Moisture

(%) Particle size

(µm) Hardness Pre-treatment

Green scraps Broken tiles 0-3 < 100 Low Grinding Dust from the

cleaning system

Powder 0-2 < 100 Low Not necessary

Concentrated glaze sludge Sludge CS: 20-30

% < 100 Medium Magnetic

separation + sieving at 150 µm + Filtrerpressing

Dilutes glaze sludge Aqueous Density

1.06 g/cm3 < 100 Medium Magnetic

separation + sieving at 150 µm + Filtrerpressing

Glazes Sludge Density 1.60 g/cm3 < 100 Medium

Magnetic separation +

sieving at 150 µm + Filtrerpressing

Fired scraps Broken tiles < 1 Consolidated material

Medium -high Crushing-Jaw mill

Polishing sludge Sludge 20-25 < 500 Medium -

high Magnetic

separation + Filtrerpressing

Dust from the kiln filters Powder <1 < 100 Low Not necessary

Fly ash Powder <1 < 100 Medium Not necessary Recycled glass Granular <1 Consolidated

material Medium -

high Grinding

35

Table A12. Summary of the results obtained in the milling study.

Type of mill Hammer Hammer Pendulum Pendulum Hammer Hammer Discs Discs Operating

variables 200 µm 500 µm Energetic Moderate 500 µm 1000

µm 500 µm

1000 µm

Waste Green scraps

Green scraps

Green scraps

Green scraps

Fired scraps

Fired scraps

Fired scraps

Fired scraps

Consumption

without

feeding

(kW·h/h)

0.21 0.21 1.59 1.00 0.2 0.2 0.34 0.35

Total

consumption

(kW·h/h) 0.79 1.19 1.66 1.02 1.4 0.7 0.66 0.67

Milling

consumption

(kW·h/h) 0.58 0.99 0.07 0.02 1.2 0.5 0.32 0.33

Output

(kg/h) 11 99 26 15 70 89 36 58

Total specific

consumption

(kW·h/Tn) 71 12 63 70 20 8.0 18 11

Milling

specific

consumption

(kW·h/Tn)

53 10 2.8 1.0 17 5.7 9 5.6

Reject at 100

µm (%) 40.1 63.1 3.7 7.7 35.7 53.0 64.9 79.0

Reject at 150

µm (%) 35.7 2.5 3.4

Reject at 180

µm (%) 8.0 1.1 1.3

Reject at 200

µm (%) 13.1 19.4 51.2

Reject at 400

µm (%) 0.3 2.4 29.7

Reject at 500

µm (%) 12.6 54.0

Reject at 710

µm (%) 3.3 43.7

36

Table A13. Summary of the results obtained in the granulation study.

Type of granulator Granulator 1 Granulator 2 Granulator 2 Rotor speed (rpm) 4800 210 380 Mixing water (%) 13.0 12.0 13.0 Granulate moisture (%) 11.0 11.2 12.0 Total consumption (kW·h/h) 2.46 1.18 1.18 Granulation consumption (kW·h/h) 0.17 0.00 0.01 Solid load (g) 2000 755 755 Total specific consumption (kW·h/tn) 105.2 106.9 103.7 Specific granulation consumption

(kW·h/tn) 7.3 0.0 0.8

< 125 µm 3.7 9.1 1.2 125 - 200 µm 8.4 9.8 2.4 200 - 300 µm 19.1 13.9 6.8 300 - 500 µm 36.0 26.8 22.3 500 - 710 µm 19.9 19.8 26.6 > 710 µm 12.8 20.6 40.8 Hausner index 1.25 1.31 1.22 Powder bulk density (g/cm3) 1.111 1.151 1.180 Tap bulk density (g/cm3) 1.390 1.515 1.440 Compact dry bulk density (g/cm3) 2.035 1.994 2.055 Dry bending strength (kg/cm2) 18 15 21 Compact fired bulk density (WA =3%)

(g/cm3) 2.345 2.406 2.385

Temperature for WA=3% (ºC) 1159 1178 1148 Table A14. Data for the spray-dried process.

Water consumption (m3/t) 0.44 Thermal energy consumption (kWh/t) 509 Electrical energy consumption (kWh/t) 39.5 Table A15. Water balance in the test.

Raw materials moisture (m3/t) 0.035

Granulation water (m3/t) 0.103 Granulate moisture after granulation (m3/t) 0.138 Granulate moisture after drying (m3/t) 0.067 Evaporated water (m3/t) 0.071

Table A16. Thermal energy consumption for the granulate drying.

Granulate moisture before drying (m3/t) 0.138

Granulate moisture after drying (m3/t) 0.067 Energy input (kWh/t) 100

Table A17. Electrical energy consumption in the milling (kWh/t).

Hammer mill (green scraps) 23

Hammer mill (fired scraps) 9 Granulator+sieving+dryer 20 Other (belts. compressed air. etc.) 6* Total 42 *estimation

37

3

4

5

6

7

8

1140 1160 1180 1200 1220 1240Temperature (ºC)

Line

ar s

hrin

kage

(%)

0

2

4

6

8

10

Wat

er a

bsor

ptio

n (%

)50TCr/50TCd

45TCr/45TCd/10LE

L.S. W.A.

Figure A1. Vitrification diagrams of the formulated body compositions.

Table A18. Formulated body compositions (wt %).

Composition 45TCr/45TCd/

10LE/0.5FH 45TCr/45TCd/

10LP/0.5FH Green scrap 45 45 Fired scrap 45 45 Glaze sludge 10 - Polishing sludge - 10 Dust from kiln filters 0.5 0.5 Table A19. Pressing conditions of the formulated compositions.

Composition 45TCr/45TCd/10LE 45TCr/45TCd/

10LE/0.5FH 45TCr/45TCd/

10LP/0.5FH Moisture content (%) 5.5 5.5 5.5 Pressure (kg/cm2) 250 250 250 Dry bulk density (g/cm3) 2.012 2.017 1.945

Table A20. Firing temperature and properties for a water absorption of 3%.

Composition 45TCr/45TCd/10LE 45TCr/45TCd/

10LE/0.5FH 45TCr/45TCd/

10LP/0.5FH Temperature (ºC) 1168 1165 1148 Bulk density (g/cm3) 2.398 2.374 2.342 Linear shrinkage (%) 6.7 6.1 6.7 Loss on ignition (%) 3.81 4.01 3.90 Table A21. Formulated body compositions (wt %).

Composition 45TCr/45TCd/

5LE/5LP/0.5FH 45TCr/45TCd

7.5LE/2.5LP/0.5FH 45TCr/45TCd

7.5LE/2.5LP/0.25FH

Green scrap 45 45 45 Fired scrap 45 45 45 Glaze sludge 5 7.5 7.5 Polishing sludge 5 2.5 2.5 Dust from kiln filters 0.5 0.5 0.25

38

Table A22. Pressing conditions of the formulated compositions.

Composition 45TCr/45TCd/

5LE/5LP/0.5FH 45TCr/45TCd

7.5LE/2.5LP/0.5FH 45TCr/45TCd

7.5LE/2.5LP/0.25FH Moisture content (%) 535 5.5 5.5 Pressure (kg/cm2) 250 250 250 Dry bulk density

(g/cm3) 1.980 1.998 2.005

Table A23. Firing temperature and properties for a water absorption of 3%.

Composition 45TCr/45TCd/

5LE/5LP/0.5FH 45TCr/45TCd

7.5LE/2.5LP/0.5FH 45TCr/45TCd

7.5LE/2.5LP/0.25FH Temperature (ºC) 1155 1158 1163 Bulk density (g/cm3) 2.360 2.368 2.355 Linear shrinkage (%) 7.0 6.8 6.5 Loss on ignition (%) 3.92 3.94 3.78 Table A24. Admissible limits for inert wastes according to Directive 1999/31/CEE and results of leaching tests on the optimum composition.

Element (mg·kg-1)

Inert wastes 45TCr/45TCd/

7.5LE/2.5LP/0.25FH Pb 0.5 <0.5 Chloride 800 29 Sulphate 1000 28 Table A25. Gaseous emissions (SO2, HF and HCl) of a floor tile body composition and optimum composition

Sample ppm SO2 ppm

HF ppm HCl

Body composition 94 221 58 45TCr/45TCd/7.5LE/2.5LP/0.25FH 116 207 18

Figure A2. Microstructure of the fired specimens from a) floor tile composition prepared by wet milling and spray-drying, b) the optimum body composition for the urban tile prepared by dry milling and granulation.

39

Table A26. New body formulation tested for the development of glazed tiles.

Composition 45TCr/45TCd/

7.5LE/2.5LP/0.25FH

45TCr/45TCd/

7.5LE/2.5LP/0.25FH

-2

Optimum

interval

Floor tile green scrap 15 19 13-17 Porcelain tile green

scrap 15 19 13-17

Wall tile green scrap 15 7 13-17 Floor tile fired scrap 15 19 13-17 Porcelain tile fired

scrap 15 19 13-17

Wall tile fired scrap 15 7 13-17 Glaze sludge 7.5 7.5 6.5-8.5 Polishing sludge 2.5 2.5 2-3 Dust from kiln filters 0.25 0.25 0.2-0.3

Figure A3. Laboratory Kiln.

Table A27. Introduction of RECUP in the FE-LIFE frit.

20%

MP-

RECUP

30%

MP-

RECUP

40%

MP-

RECUP

50%

MP-

RECUP

60%

MP-

RECUP

70%

MP-

RECUP Melting

Temperature (ºC) 1480 1480 1480 1480 1480 1480

Time (minute) 95 95 95 95 95 95 Discharge OK OK OK OK OK Not OK Melting behavior OK OK OK OK OK - Solubility OK OK OK OK Not OK - Dilatometric

Coefficient (*10-7

1/K) 174 174 180 177 - -

Transition

Temperature (ºC) 627 613 612 612 - -

Dilatometric

Softening Point (ºC) 700 682 681 686 - -

40

Figure A4. Thermal expansion curve of FE-Life

Table A28. Definition of the frit mixtures.

Visual

appearance 5% FE-LIFE 8% FE-LIFE

10% FE-

LIFE

12% FE-

LIFE

14% FE-

LIFE

1% FE-OP - - - - ok

3% FE-OP - - - ok -

5% FE-OP - - ok - -

7% FE-OP - Deficient melting behavior

- - -

10% FE-OP

Deficient melting behavior

- - - -

Table A29. Engobe formulations tested. N N1

FE-LIFE 10 10 FE-OP 5 5 Clay 37 25 Kaolin 7.8 29.6 Feldspars 11 26 Zirconium silicate 4 4 Quartz 25 - Sodium triphosphate 0.2 0.4

Table A30. Dilatometric coefficients of the engobes.

N N1

Dilatometric coefficient (*10-7 1/K) 183 161 Table A31. Definition of the frit mixtures.

FE-OP FE-CR FE-MA STD frit Visual appearance

5 5 10 15 Glossy and not stable 3 2 10 20 Ok 5 5 5 20 Glossy 3 2 15 15 Not stable 2 - 8 25 Ok

Table A32. Dilatometric coefficient of the glazes. E E1

Dilatometric coefficient (*10-7 1/K) 210 200

41

Table A33. Glaze formulations tested. E E1

FE-OP 10 10 FE-CR 2 2 FE-MA 3 3 Frit 20 17.4 Kaolin 8 7.4 Alkaline earth carbonates 10 9.3 Feldspar 46.6 43.1 Cola 0.2 0.2 Sodium triphosphate 0.2 0.2 Zirconium silicate - 7.4

42

Table A34. Tests performed with the engobes and glazes developed.

TEST BODY APPLICATIONS FIRING APPEARANCE BENDING SLIPPING OBSERVATIONS

A1

10*15 STD FLOOR RED BODY

N/E SLIDE 04 1170/1170 v:300 Matt OK 66 Excessive Rd. It

stains

A2

10*15 STD FLOOR RED BODY

N/E SLIDE 04 1180/1180 v:250 Semi-matt OK 24 Rd slightly low.

Does not stain

B1

10*10 STD FLOOR RED BODY

N/E DISK 1170/1170 v:300 Matt OK Not

measurable Not correct. It stains

B2

10*10 STD FLOOR RED BODY

N/E DISK 1180/1180 v:250 semi-matt

OK Not measurable OK

C1 10*10 BODY LIFE 1

N/E DISK 1170/1170 v:300

Slightly more glossary than B1

Bent upwards

Not measurable

Different BODY reactivity. Does not stain

C2 10*10 BODY LIFE 1

N/E DISK 1180/1180 v:250

Slightly more glossary than B2

Bent upwards

Not measurable

Different BODY reactivity. Does not stain

D1 10*10 BODY LIFE 1

N1/E1 DISK 1170/1170 v:300 semi-matt Bent

upwards Not measurable

Different BODY reactivity. Does not stain

D2 10*10 BODY LIFE 1

N1/E1 DISK 1180/1180 v:250 semi-matt Bent

upwards Not measurable

Different BODY reactivity. Does not stain

E1 10*10 BODY LIFE 1

N1/E1 DISK 1160/1170 v:300 semi-matt Bent

upwards Not measurable

Different BODY reactivity. Does not stain

E2 10*10 BODY LIFE 1

N1/E1 DISK 1170/1180 v:250 semi-matt Bent

upwards Not measurable

Different BODY reactivity. Does not stain

F1 10*10 BODY LIFE 1

N1/E1 DISK 1150/1170 v:300 semi-matt Bent

upwards Not measurable

Different BODY reactivity. Does not stain

F2 10*10 BODY LIFE 1

N1/E1 DISK 1160/1180 v:250 semi-matt Bent

upwards Not measurable

Different BODY reactivity. Does not stain

G 10*10 BODY LIFE 1

No applications 1170/1170 v:300 Not applicable Bent

upwards Not measurable

BODY alone already bends

G1 10*10 BODY LIFE 1

Solo N1 DISK BODY pre-fired

1170/1170 v:300 Not applicable Bent

upwards Not measurable

Engobe is not capable of correcting bending

G2 10*10 BODY LIFE 1

N1/E1 DISK BODY pre-fired

1170/1170 v:300 semi-matt Bent

upwards Not measurable

Glaze and engobe are not capable of correcting bending

H 10*10 BODY LIFE 2

No applications 1130/1130 v:250 Not applicable OK

slightly ↑ Not measurable

Corrected by porous firing

H1 10*10 BODY LIFE 2

N/E DISK 1170/1170 v:300 Semi-matt Bent

upwards Not measurable

Glaze and engobe are not capable of correcting bending

43

Table A35. Thermal expansion and coefficients of the optimum body composition and Intervals of variation for the different body compositions produced in Spain.

Interval

45TCr/45TCd/7.5LE/ 2.5LP/0.25FH

45TCr/45TCd/7.5LE/ 2.5LP/0.25FH-2

Red body floor tile

Red body wall tile

White body wall tile

Porcelain tile

Expansion at 700 ºC 5.0 5.1 5.9-

6.0 5.4-5.7

4.8-5.3 5

α 50-30 65 67 73-77

68-73 58-70 62

α 300-500 80 83 96-97

85-89 73-77 82

-70

-60

-50

-40

-30

-20

-10

0

10

20

0 200 400 600 800 1000 1200

Temperature (ºC)

Expa

nson

(‰)

TCr/TCd/10LE

Red body floortile

Red body walltile

Figure A5. Dilatometric curves for dried specimens.

44

Figure A6. Measurement of the electric energy input during the milling and granulation trials.

Figure A7. Milling at Ch&T.

45

Figure A8. Feeding the hammer mill with filtercaked sludge (left) and milled waste (right).

Figure A9. Preparing the body composition mixture for the granulation (left) and granulation (right).

46

Body composition milling

Table A36. Electric Power consumption.

Total consumption 9.51 kW·h/h

Production 470 kg/h

Specific consumption 20.25 kW·h/tn

0

2000

4000

6000

8000

10000

12000

14000

16000

0 5 10 15 20 25 30 35

Time (minute)

Pow

er (W

)

Figure A10. Electric consumption during the milling.

Table A37.Waste moisture and particle size.

Wall

tile

unfired

Wall

tile

fired

Floor

tile

unfired

Floor

tile

fired

Porcelai

n

unfired

Porcelai

n

fired

Glaze

sludge

Polishing

sludge

Moisture (%) 2.0 0.2 1.6 0.1 2.0 0.1 9.5 20.6 < 100 mm 39.7 68.8 47.8 69.8 27.8 58.8 24.3 35.1 100-200 mm 31.6 24.0 22.9 23.7 32.7 30.3 5.3 11.2 200-300 mm 18.4 5.8 19.7 5.1 26.4 9.3 7.0 12.5 > 300 mm 10.3 1.5 9.6 1.4 13.2 1.6 63.4 41.2

47

0

10

20

30

40

50

60

70

80

90

100

> 300 m200 - 300 m100 - 200 m< 100 m

Reje

ct

(%)

Green scraps wall tile Fired scraps wall tileGreen scraps floor tile Fired scraps floor tileGreen scraps stoneware tile Fired scraps stoneware tilePolish sludge Glaze sludge

m m m m

Figure A11. Particle size distribution.

0

2000

4000

6000

8000

10000

12000

14000

16000

0 10 20 30 40 50 60 70 80

Time (minute)

Pow

er (W

)

Figure A12. Electric consumption during the granulation and drying.

48

Granulate properties

Table A38. Granule size distribution.

Granulate 1 Granulate 2 Floor tile Porcelain Fraction < 125 µm 22.5 5.5 7.5 3.5 % Fraction 125 - 200

µm 15.0 12.0 15.0 10.5 %

Fraction 200 - 300

µm 17.2 9.6 26.0 27.5 %

Fraction 300 - 500

µm 21.3 19.0 36.0 46.0 %

Fraction 500 - 710

µm 10.7 18.6 11.5 9.5 %

Fraction > 710 µm 13.4 35.4 4.0 2.5 %

Table A39. Granule characteristics

Granulate 1 Granulate

2 Floor tile Porcelain

Filling density 989 ± 21 1073 ± 10 950 930 (kg/m3) Tap density 1206 ± 27 1325 ± 16 1100 1050 (kg/m3) Hausner index 1.22 ± 0.03 1.23 ± 0.03 1.20 1.22 -

Table A40. Pressing.

Granulate 1 Granulate 2 Floor tile Porcelain Pressure 400 400 250 350 kg/cm2 Moisture 6.0 6,0 5.5 5.5 % Dry bulk density 1.855 1.918 1.980 1.950 g/cm3 Table A41. Firing.

Granulate 1 Granulate 2 Floor tile Porcelain Bulk density

(Water absorption

=3%) 2.305 2.319 2,360 2,410 g/cm3

Shrinkage 6.4 6.7 6.5 7.9 % Temperature

(Water absorption

=3%) 1157 1150 1135 1200 ºC

49

3

4

5

6

7

8

1110 1130 1150 1170 1190 1210 1230

Temperature (ºC)

linea

r shr

inka

ge (%

)

0

2

4

6

8

10

12

14

Wat

er a

bsor

ptio

n (%

)

Industrial granulation 1

Green body floor tile

Stoneware tile

L.S.

W.a.

Figure A13 . Vitrification diagram.

1,75

1,80

1,85

1,90

1,95

100 1000

Presión (kg/cm2)

Den

sid

ad

ap

aren

te (

g/c

m3)

Granulado industrial

300 600

Figure A14. Compaction diagram of granulate 2

50

1

2

3

4

5

6

7

8

1110 1120 1130 1140 1150 1160 1170 1180 1190 1200 1210

Temperatura (ºC)

Co

ntr

acc

ión

lin

eal

(%)

0

1

2

3

4

5

6

7

Ab

sorc

ión

de

ag

ua

(%

)

Granulado industrial C.L. A.a.

Figure A15. Vitrification diagram og granulate 2.

51

Table A42. Firing cycles used in the previous tests.

HORNO CARFER

33X33 41X41 33X33P 33X67P 50X50P 50X50P

MATE MATE MATE MATE BRILLO BRILLO

1 350 350 350 350 350 350 10 690 690 740 700 750 750

Abajo 690 690 720 640 710 710 12 810 810 850 825 850 850

Abajo 860 860 850 830 850 850 14 980 940 950 960 950 950

Abajo 980 960 950 980 950 950 16 980 970 990 990 990 990

Abajo 1000 990 990 1010 1000 1000 18 980 970 1000 1000 1000 1000

Abajo 1000 990 1000 1010 1030 1030 20 990 980 1030 1040 1040 1040

Abajo 1020 990 1030 1050 1080 1080 22 1070 1090 1150 1170 1130 1130

Abajo 1100 1090 1150 1170 1150 1150

23 1120 1110 1177 1170 1170 1170

Abajo 1150 1120 1177 1170 1180 1180

24 1153 1152 1180 1189 1174 1177

Abajo 1153 1162 1190 1189 1182 1185

25 1153 1152 1180 1189 1174 1177

Abajo 1153 1162 1190 1189 1182 1185

26 1153 1152 1180 1189 1174 1177

Abajo 1153 1162 1190 1189 1182 1185

27 1105 1090 1135 1155 1130 1130

Abajo 1125 1150 1170 1135 1160 1160

28 660 660 650 658 650 650 29 620 620 625 635 610 610 30 580 580 585 590 570 570

Abajo 530 550 550 545 520 520 31 570 570 560 580 560 560 32 565 565 560 575 555 555 33 560 560 560 570 550 550 36 400 400 400 400 400 400 38 300 300 300 300 300 300 42 200 200 200 200 200 200 44 100 100 100 100 100 100 45 min. 45 min. 45 min. 50 min. 55 min. 60 min.

52

Table A43. Pressing variables and tile properties

Pressing

Trial nº 1 2 3 4 5

Size 33x33P 33x33P 33x33P 33x33P 33x33P

Fines (%) <125 µm=22.5

<125 µm=22.5

<125 µm=22.5

<125 µm=5.5

<125 µm=5.5

Moisture (%) 9,7 7,2 7,2 6,8 6,8 Pressure I (bar) 26 26 26 30 30 Pressure I (Kg/cm2) 43 43 43 53 53 Pressure II (bar) 240 240 240 280 280 Pressure II (Kg/cm2) 400 400 400 492 492 Desaireación parameter (seg) 1 1 1 1 1 Green bulk density (g/cm3) 1.87 1.91 1.91 2.07 2.07 Dry bulk density (g/cm3) 1.75 1.80 1.80 1.93 1.93

Drying

Exit temperature (ºC) 105-115 105-115 105-115 105-115 105-115 Dry bending strength (N/mm2) - - - 1.8 1.9

Table A44. Glazing and decoration variables

Glazing and decoration

Trial nº 1 2 3 4 5

Engobe and Glaze

Gramaje Engobe (g/tile) 45 45 45 45 45 Density Engobe (g/cm3) 1780 1780 1780 1780 1780 Viscosity Engobe (seg) 35 35 35 35 35 Gramaje Glaze (g/ tile) 45 45 45 45 45 Density Glaze (g/cm3) 1800 1800 1800 1800 1800 Viscosity Glaze (sec) 50 50 50 50 50

Inks

Gramaje INKJET BROWN (g/ tile) 1.158 1.158 1.158 1.158 1.158 Gramaje INKJET BLUE (g/ tile) 0.292 0.292 0.292 0.292 0.292 Gramaje INKJET YELLOW (g/ tile) 1.692 1.692 1.692 1.692 1.692 Gramaje INKJET ROSA (g/ tile) 0.145 0.145 0.145 0.145 0.145

Coating

Gramaje (g/cm3) - - - 15 -

Density (g/cm3) - - - 1350 - Viscosity (seg) - - - 19 -

53

Table A45. Firing variables and tile properties

Firing and sorting

Trial nº 1 2 3 4 5 Cycle (min) 45 45 45 45 60 Maximum temperature (ºC) 1153 1153 1185 1185 1185 Modules a Tmax - (time (min)) 3 3 3 3 3 Bulk density (g/cm3) 2.24 2.23 2.29 2.32 2.35 Water absorption (%A.A.) 8.2 10.3 4.2 2.7 1.6 Shrinkage (%C.L.) 5.1 4.1 5.2 6.4 6.6 Bending strength. EN ISO 10545-4 (N/mm2) 20 21 31 38 42 Slip resistance. ENV 12633. USRV - - - 54 -

Sorting Descuadre LIFECERAM (mm) - - - 0.33 0.34 Flatness LIFECERAM (mm) - - - 0.10 0.09 Luneta LIFECERAM (mm) - - - 0.00 0.00

Table A46. Main problems detected in the industrial trials.

Main problems

1 2 3 4 5

Excess of fines Excess of fines Excess of fines Superficial defects -

Excess of moisture Lamination Lamination High water absorption -

Lamination High water absorption

Superficial defects -

Weak tiles Superficial defects - High water absorption Cracks -

Figure A16. Granulate with an excess of fines.

54

Figure A17. Problems of cracks and laminations in the first industrial trials.

Figure A18. Glazing with a bell (left), unglazed tile (top right) and glaze tile (bottom right) of trial 5.