UCTEA Chamber of Metallurgical & Materials Engineers Proceedings Book

32 IMMC 2016 | 18th International Metallurgy & Materials Congress

Usage of Boron Wastes in the Commerically Produced and Used ZrCMS System Opaque Frit Composition

Fatma Aksu¹, Ayşe Tunalı¹, Neslihan Tamsu Selli¹, Buğra Çiçek², Emre Talşık¹

¹Eczacıbaşı Building Product Co., ²Yıldız Technical University - Türkiye

Abstract Over the past two decades there was growing interest in the development of frits that are able to crystallise on firing because of the need for improvement in the mechanical and chemical properties of glazed tiles. The ZrO2-CaO-MgO-SiO2 (ZrCMS) glass-ceramic system is one of these and exhibits high resistance to abrasion and surface scratches. In this present study, boron wastes of Eti Mine Boron Company, which appear at huge amounts during processess, were characterized and added into the commerically produced and used ZrCMS system opaque frit composition. New compositions were applied on tile bodies, and then fast fired under industrial working conditions. Newly-produced glazes were characterized in terms of optical, mineralogical and microstructural properties. 1. Introduction Boron is a metalloid chemical element with symbol B and atomic number is 5. It is not found naturally on Earth. It takes part more than in 230 mineral in nature [1]. The 90 % of the boron minerals used in industry worldwide are sodium and calcium borates, as borax, kernite, colemanite and ulexite. There are more than 300 end uses linked with borates (glass, agriculture, ceramics, cleaning products (detergents, soaps, bleaches), metallurgy, corrosion inhibitors, flame retardation, wood preservation, adhesives and abrasives) [2]. The world’s largest boron reserves are located in Turkey, U.S.A and Russia. Turkey is the luckiest country possessing 72.1 % of total world boron reservations [1]. Boron is mined Bigadiç, Emet, K rka and Band rma region of Turkey by Eti Mine Boron Company. The most important boron minerals in Turkey are colemanite, ulexite and tincal. These boron minerals are concentrated to increasing the grade of B2O3 and wastes are discharged during the concentrated processes [2]. A problem is the

large quantity of boron wastes which are generated and have to be disposed. The increasing costs of some traditional raw materials for ceramics industry are leading to a necessity for the use of complementary alternatives. The aim of the present study is to utilize Eti Mine Band rma Boron Company colemanite wastes in a commerically produced ZrCMS glass-ceramic system opaque frit composition instead of boric acid. New compositions were applied on wall tile bodies, then fast fired under industrial working conditions. Finally, newly-produced glazes were characterized. 2. Experimental Procedure Colemanite wastes (A5 and A6) were suplied by Eti Mine Band rma Boron Company. The wastes of chemical compositions were presented Table 1. Table 1. Chemical compositions of the colemanite wastes

(in wt. %)

Oxides A5 A6 B2O3 29,52 31,12 Na2O 0,91 0,82 MgO 0,82 0,60 Al2O3 0,11 0,63 SiO2 0,39 1,28 P2O5 0,01 0,01 SO3 0,56 0,77 K2O - 0,04 CaO 52,75 33,42

Fe2O3 0,14 0,14 Cr2O3 - 0,04 SnO2 - 0,34 *L.I. 14,80 30,80 Total 100,00 100,00 *L.I.: Losses on ignition.

TMMOB Metalurj i ve Malzeme Mühendisleri Odas ıBildir i ler Kitab ı

3318. Uluslararas ı Metalurj i ve Malzeme Kongresi | IMMC 2016

The mat opaque frit, which has been produced by Eczac ba Building Product Co., is accepted as a reference (MOF1). MOF1 frit, which is huge amounts produced, is used in glazes and engobes recipes. New recipes were prepared with colemanite wastes to utilizing colemanite wastes in MOF1 frit recipes. The frit that was formed with A5 was coded MOF1-A5 and the frit that was formed with A6 was coded MOF1-A6. Table 2. Compositional details of studied frits (in moles)

COMPONENT MOF1 MOF1-

A5 MOF1-

A6

Content

R2O (Na2O, K2O) 1,17 1,3 1,32

RO (CaO, MgO, ZnO) 35,50 35,75 35,4

R2O3 (B2O3, Al2O3, Fe2O3)

6,60 6,55 6,64

RO2 (SiO2, ZrO2)

56,73 56,4 56,7

TOTAL 100 100 100 Oxides ratio

SiO2/Al2O3 45,587 44,725 42,987 MgO/CaO 0,910 0,901 0,905

B2O3 Total B2O3 0,146 0,143 0,145

*B2O3 (BW) 0 0,143 0,145

*B2O3 (BW): B2O3 amount from wastes Boric acid that is used in MOF1 recipe, was removed in MOF1-A5 and MOF1-A6 frits recipes. Furthermore, the amount of dolomite that used as source of CaO and MgO, decreased in the new recipes. Thus, all amount of B2O3 and a far amount of CaO and MgO were provided from the wastes. The weighed and thoroughly mixed batches were melted in alumina crucibles in a Protherm series laboratory type electrically heated furnace at 1450°C for 1 h. The melt was then quenched by pouring into cold water to obtain frits under laboratory working conditions. In order to prepare glazes suitable amounts of frit, kaolin, carboxyl methyl cellulose (CMC), sodium tripolyphosphate (STPP) and water were mixed in a Ceramic Instruments Rapid Mills-Moduler System SD series jet-mill containing alumina balls for 14 minutes. The slurries were applied onto industrial wall tile body without engobe. The glazed tiles were dried in a Nüve FN 40 laboratory type furnace at 100 oC for 2 h. After drying, glazed tiles were fired in a fast firing furnace in Eczacibasi Building Product Co. at 1145 oC for a total time of 36 minutes. The glaze that was formed with MOF1-A5 frit was coded MOF1-A5 glaze and the frit that was formed with MOF1-A6 was coded MOF1-A6 glaze. Microstructural changes and phase formations of the glazes were inspected with a Rigaku Rint 2000 series diffractometer (XRD) and a Zeiss Evo 50 EP series scanning electron microscope (SEM/EDX). Glossiness,

colouring and roughness parameteres of the glazes were determined using a Konica Minolta Multi Gloss 268 Plus model gloss meter, a X-rite model colorimeter and a Ceramic Instruments KR 100 model profilometer. 3. Results and Discussion If the values of brightness and surface roughness of glazes were presented in Table 3, it can be seen that MOF1-A5 is more similar to the standard glaze. MOF1-A6 glaze is brighter than the standard glaze and its surface roughness is rather less. As far as brightness values are compared, the comparison would be MOF1-A6 > MOF1-A5 > MOF1 and as far as surface roughness values are compared, it would be MOF1-A5 > MOF1 > MOF1-A6. When the whiteness are compared, it is seen that MOF1-A5 and MOF1-A6 have close values to each other and little less values than MOF1 glaze. Table 3. Glossiness, colouring and roughness parameteres

of the glazes

MOF1 MOF1-A5 MOF1-A6

COLOUR

L 92,47 90,94 90,45

a* -0,1 0,22 0,32

b* 0,76 1,4 1,64

BRIGHTNESS

20 ° 1,1 1,1 1,4

60 ° 2,4 2,7 6,2

80 ° 2,4 2,9 7,2

ROUGHNESS m 18,72 19,35 10,13

According to the XRD results were presented in Figure 1, diopside and zircon crystals in addition to a small amount of amorphous phase were determined in all glazes. While the wide elevation at 20-35o 2 , which belongs to amorphous phase, do not be seen clearly MOF1 glaze, it is rather clearer in the new glazes. In standard MOF1 glaze, the peak intensities of diopside crystals are higher than the ones in zircon crystals. In MOF1-A5 glaze, peak intensities of zircon and diopside crystals have become almost equal.

UCTEA Chamber of Metallurgical & Materials Engineers Proceedings Book

34 IMMC 2016 | 18th International Metallurgy & Materials Congress

Figure 1. X-ray diffraction paterns of the MOF1, MOF1-

A5 and MOF1-A6 glazes. When investigated the microstructure of MOF1, MOF1-A5, MOF1-A6 glazes, two different crystals can be seen homogenously distributed light ones and dark ones. It is also observed that the light crystals are a thin stick while the dark ones are in a larger and dispersed way. As a result of the EDX analysis made on the crystals marked as “Z” in Figure 2,3 and 4, were detected peaks which belong to the elements Zr and Si. As a result of the EDX analysis made on the crystals marked as “D” in Figures 2, 3 and 4, were detected peaks which belong to the elements Si, Mg, Ca and Al. The EDX results agreed with the XRD data confirming both zircon and diopside cyristallizations.

(a)

(b) (c)

Figure 2. (a) SEM micrographs of the MOF1, (b) EDX analyses taken from “Z” (Zircon) cyrstal and (c) EDX

analyses taken from “D” (Diopside) cyrstal.

(a)

(b) (d)

Figure 3. (a) SEM micrographs of the MOF1-A5, (b) EDX analyses taken from “Z” (Zircon) cyrstal and (c)

EDX analyses taken from “D” (Diopside) cyrstal.

(a)

(b) (c)

Figure 4. (a) SEM micrographs of the MOF1-A6, (b) EDX analyses taken from “Z” (Zircon) cyrstal and (c)

EDX analyses taken from “D” (Diopside) cyrstal.

TMMOB Metalurj i ve Malzeme Mühendisleri Odas ıBildir i ler Kitab ı

3518. Uluslararas ı Metalurj i ve Malzeme Kongresi | IMMC 2016

Using of borax wastes by not changing the Seger formulas of standard glazes does not affect the crystallization and microstructure of the glaze and not deteriorate the desired matte surface texture. Similar results have been reported in the literature. [3-4] 4. Conclusion Boric acid that is used in MOF1 recipe source of B2O3, was removed in MOF1-A5 and MOF1-A6 frits recipes. The whole amount of B2O3 in the recipes were provided from wastes Furthermore, the amount of dolomite that used as source of CaO and MgO, were decreased by 66.67 % in MOF1-A5 recipe and by 41.3 % in MOF1-A6 recipe and some amount of the CaO and MgO requirements is provided from wastes. Using of boron wastes by not changing the Seger formulas of standard frits does not affect the crystallization and microstructure of the glaze. Even though there have been increases in the brightness values, decreases in the surface roughness and whiteness values of the glazes obtained by the use of MOF1-A5 and MOF1-A6 frits, these differences do not have a negative effect on usage of frit in glazes. Finally, it can be understood that frits prepared with colemanite wastes in the ZrCMS glass ceramics system can be easily used without leading to any surface failure or fault. Acknowledgment The authors would like to thank to BOREN (National Boron Research Institute) for the financial support to the Project numbered 2015-31-07-15-002. References [1] http://www.etimaden.gov.tr/ Dated: 02.05.2016 [2] B. C cek, L. Espos to, A. Tucc , E. Bernardo, A. R. Boccacc n and P. A. B ngham, Microporous Glass Ceramics From Combination Of Silicate, Borate and Phosphate Wastes, (2012). [3] B. Karasu, Use of Borax Solid Wastes in Ceramics’ World, Anadolu University, Faculty of Engineering and Architecture, Department of Materials Science and Engineering, (2007). [4] B. Karasu, G. Kaya, A. Çak r, and S. Ye ilay, Ut l zat on Of Borax Sol d Wastes In Fast S ngle-F r ng Porcela n T le Glass-Ceram c Glazes Under Industr al Work ng Cond t ons, Anadolu University; Department of Materials Science and Engineering, (2008).