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MINING CHEMICALS

REPROCESSING & TAILINGS REDUCTION

FLEET MANAGEMENT

GRAVITY, MAGNETIC, DENSITY SEPARATION

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Whether it is for dewatering, mineral/

metal recovery, optimisation of mineral

processing, or long-term protection of

key equipment, the use of mining chemicals is

vital to the success of today’s operations.

As mining companies take on the challenge of

processing even more complex ores, using the

right chemicals – with the right dosages – will

continue to be critical into the future.

Yet, as manufacturers of reagents, frothers and

processing aids are being asked to develop more

effective products, they are also battling with

requirements to lower the impact on the

workforces that interact with these chemicals and

the environment in which they work.

Reduced exposure Bernard Oosterndorp, Technical Manager at

South Africa-based reagent producer Axis House,

has seen the company’s clients demand exactly

this – products that reduce handling or mixing on

site.

“We have seen a gradual move away from

xanthates to liquid sulphide collectors for this

very reason,” he told IM.

While xanthates have been used in sulphide

flotation since 1924 and are the most widely used

sulphide collector in the flotation space, they

pose some major risks, according to fellow

reagent producer Clariant.

They present health risks to workers, come

with disposal challenges for mining companies,

may require additional infrastructure for

handling, and are classified as a fire and

explosion hazard by many regulators, according

to the company.

Business Queensland, an arm of the

Queensland Government, classifies xanthates as

liable to spontaneous combustion in the

Australian Dangerous Goods (ADG) Code, adding

that they pose a number of hazards due to their

nature, the vast quantities used in industry and

the climate conditions at most Queensland mines

using them.

For these reasons, it is hardly surprising there

has been a gradual market move away from

xanthates.

In the lead flotation process, Eammon Guitard,

Global Marketing Manager, Mineral Processing,

at Solvay Mining Solutions, says the company

has seen more and more polymetallic (Cu/Pb/Zn)

mines requesting selective collectors to replace

xanthates in the flotation process.

“Today over 40% of the industry has switched

to alternative products,” he said, adding that

Solvay’s AEROPHINE® is one of the leading

technologies in these applications.

Going to trial Clariant says its own push to replace xanthates

worldwide is driven by three major factors.

One is the simplification of flotation circuits

through avoiding the use of multiple collectors

where possible.

Two is the elimination of the need for

operational mine employees to handle large

amounts of xanthate powder or pellets.

Three is the problems associated with

discarding contaminated packaging.

“The goal to replace xanthates that have been

in use for nearly 100 years is an ongoing challenge

for the Clariant Mining Solutions team,” it said.

The company has been making significant

progress with this “ongoing challenge” since it

launched its HOSTAFLOT® line of xanthate

replacement technologies, part of its EcoTain®

range of products, in 2015.

The company told IM: “Clariant’s goal is to

help mining operations increase their production

efficiencies, lower production costs and improve

sustainability with their HOSTAFLOT line of

xanthate replacements.”

Clariant’s application development teams have

been working with customers to create and test

several chemistries from the HOSTAFLOT series

to replace xanthates in their respective regions,

moving the products towards commercial

applications, it said.

In a previously reported initial plant trial of

HOSTAFLOT chemistry at a large copper/gold

mine in Brazil, collector consumption was

reduced by 40% and frother consumption by

25%, according to Clariant. The company noted

the mine continues to experience both lower

collector consumption and frother consumption

since the trial.

At another large copper/gold mine in Brazil,

Clariant said the HOSTAFLOT xanthate

replacement technology was able to replace not

only the xanthate but also the supplemental

collector, resulting in an overall reduction in

collector consumption of 33%. Frother

consumption has also been reduced by 50% at

this mine.

“In both copper mines, metallurgical targets

for copper recovery continue to be achieved, with

operational acceptance in the plants,” Clariant

said. “Additional mines in Brazil have shown

interest in the HOSTAFLOT xanthate replacement

chemistries, and laboratory qualification is

ongoing in gold flotation plants.”

In Chile, some of the largest copper mines

have moved from xanthate to HOSTAFLOT

xanthate replacement technology, according to

Clariant.

Plant results have indicated a 1% improvement

in copper recovery over sodium isopropyl

xanthate, with the HOSTAFLOT collector

indicating a better response at a lower pH than

xanthates, which results in less lime

consumption and lower reagent costs for the

operator, Clariant explained.

“Currently there are gold flotation plants in

Chile undergoing lab trial qualifications to

evaluate whether the HOSTAFLOT xanthate

replacement product can replace their xanthate

collector,” the company added.

In Australia, a plant trial is ongoing at a large

copper/gold mine where the miner is evaluating

one of the HOSTAFLOT xanthate replacement

chemistries to replace sodium ethyl xanthate in

its flotation process. There are also several

laboratory trials ongoing with a large lead-zinc-

silver-copper producer to replace sodium ethyl

xanthate in its zinc flotation circuit.

36 International Mining | MAY 2020

Balancing the formula

Dan Gleeson delves into a sector focused on providing more environmentally friendly chemicals that retain, if not increase, their effectiveness in the process plant

MINING CHEMICALS

Solvay says its AEROPHINE xanthate replacement chemical technology enables base metal miners to maximise their net smelter returns for concentrate through the effective extraction of precious metals that can be sold as by-products

MINING CHEMICALS.qxp_proof 29/04/2020 09:44 Page 1

Additional laboratory trials are being conducted

by Clariant’s mining development laboratory in

Australia on copper and gold mine flotation plants

to evaluate HOSTAFLOT xanthate replacements, in

all cases to replace potassium amyl xanthate, the

company said.

In South Africa, it is platinum and palladium

producers currently interested in HOSTAFLOT

xanthate replacement products, according to

Clariant.

At one platinum producer, the HOSTAFLOT

xanthate replacement showed the new product

can operate at a lower dosage than xanthate and

result in reduced chrome content in the

concentrate – an undesirable metal in this case, as

it increases the slag liquid temperature in the

subsequent smelting process, Clariant noted.

There are also indications from the plant trial that

frother consumption can be reduced, which will

lead to additional reagent savings for the operator.

Further, there are lab trial qualifications for

HOSTAFLOT xanthate replacements ongoing in the

new Clariant mining development lab in

Johannesburg, South Africa, with the aim of

moving to plant trials later in 2020.

It’s clear from the breadth of testing to replace

the likes of sodium isopropyl xanthate, sodium

ethyl xanthate, potassium amyl xanthate and

other xanthate collectors that there is no one-size-

fits-all flotation solution. It is also apparent some

of these replacement chemistries positively

impact more than just the effectiveness of the

collectors, the environment and personnel.

Phosphine-based flotation alternatives When it comes to the adoption of Solvay’s

AEROPHINE 3418A xanthate replacement chemical

technology, the company also sees three market

forces leading to further market adoption.

First, with base metal prices subdued, the likes

of copper, zinc and lead miners are exploring ways

to effectively extract precious metals that can be

sold as by-products. AEROPHINE enables mine

operators to maximise their net smelter returns for

concentrate, the Solvay says.

Separation efficiency is another key selling

point, with AEROPHINE enabling increased

selectivity against gangue and penalty elements,

while lowering the ore treatment cost. This

potentially increases revenue at the same time as

reducing operating expenses, the company says.

Lastly – and a point already picked up on –

AEROPHINE technology helps mines limit operator

exposure to harmful chemicals.

AEROPHINE 3418A, Solvay says, is a unique,

phosphine-based chemistry originally developed

for the flotation of copper and activated zinc minerals.

More recently, it has demonstrated selectivity

towards complex, polymetallic and massive

sulphide ores, the company said, adding that

AEROPHINE is highly selective for lead/zinc and

lead/silver minerals and exhibits strength yet

selectivity against iron sulphides (pyrite,

pyrrhotite, marcasite and arsenopyrite), non-

activated sphalerite and penalty elements.

The company has provided a few examples to

back this up.

In an application where ore from a chalcopyrite-

sphalerite deposit was being milled at a rate of

around 10,000 t/d – with the concentrator using a

conventional flowsheet of copper flotation

followed by copper sulphate activation and zinc

flotation – Solvay carried out laboratory tests on

the use of AEROPHINE.

After these lab tests were deemed successful,

the AEROPHINE 3418A promoter was introduced

for a full-scale 10-day plant trial, replacing the

standard sodium amyl xanthate and methyl

isobutyl carbinol mill promoter and frother,

respectively. This saw copper recovery increase by

around 8% and reagent dosage decrease by 30%,

according to Solvay.

The AEROPHINE 3418A promoter also induced

minor improvements in zinc grades and recoveries,

according to the company, with zinc recovery in

the copper concentrate and copper recovery in the

zinc concentrate “essentially equal” for both

collectors, it noted.

Solvay said: “The improvement in copper

metallurgy alone translates into a substantial

monthly increase in the value of copper recovered

at the mill.”

MINING CHEMICALS

MAY 2020 | International Mining 37

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Another case study looking at a trial of

AEROPHINE 3418A on a 4,000 t/d copper-zinc-

silver mine that previously used potassium amyl

xanthate provided evidence of the collector’s

precious metals recovery credentials.

The 10-month test pitted metallurgy obtained

with the standard promoter against the

performance of a mixture of AEROPHINE 3418A

promoter and potassium amyl xanthate.

Looking at the monthly silver tailings assays as

a function of head grades for nine of 10 months, it

was evident there was a trend to lower silver tails

assays with the AEROPHINE 3418A/potassium

amyl xanthate combination. The average

metallurgy over the ten-month period also saw the

use of AEROPHINE 3418A promoter increase silver

recoveries by 6%, according to Solvay.

“Small but significant improvements in copper

metallurgy were also observed together with a

small reduction of zinc reporting to the copper

concentrate,” Solvay said.

Revadep proves its worth Axis House’s Oosterndorp says its clients can

benefit from increased metal recoveries while

improving the working conditions of their staff and

streamlining their processes with the

implementation of its environmentally sensitive

products.

As Cherry Thomas, Sales Manager, Africa, says:

“Environmental regulations are…becoming stricter

and requests for alternative reagents to common,

but hazardous, chemicals (xanthates, NaHS,

cyanide, etc) are increasing.

“Axis House takes this into consideration during

the reagent development work for clients.”

Its xanthate-alternative sulphide collectors are

being used successfully at a several copper mines

in Zambia, as well as platinum and gold mines in

South Africa, according to Oostendorp.

“The European and Middle East market has

shown substantial growth in the last 18 months,

an area where we are focusing our resources to

maximise on the market potential,” he added. This

has seen multiple trials conducted and completed

at copper-lead-zinc mines in Europe and Turkey,

where sulphide collectors were successfully

trialled in full-scale applications.

Thomas said: “This allows Axis House to apply

the application knowledge and market products to

operations processing similar ore types.

Successful application of reagents also forms a

new baseline from which further development can

take place.”

Sulphide collectors are not all the South Africa-

based company is working on.

The company’s Revadep depressants range,

engineered to target specific gangue minerals in

the flotation process, has found favour with

platinum group metal producers in Africa.

Thomas said the depressants have proven

highly effective in the PGM flotation process by

reducing floatable gangue like talc.

The company is also targeting the Zambia

copper flotation market with its Revadep Cu++

depressant formula, according to Thomas. “Highly

floatable carbon is also a problematic mineral in

some operations in Zambia and the Axis House

carbon depressant, Cu++, was successfully trialled

at full scale,” she said.

In the DRC, the company’s mobile precipitation

plant, built specifically for cobalt miners to analyse

the effects of dosage, process conditions and

reagent type on different types of ores, is starting

to be appreciated by miners too, Thomas said.

And, the development of a reagent range to

remove cadmium in phosphate production has

allowed Axis House clients to cost-effectively

sustain phosphate output without bolting on

processing units like ion exchange columns, she

added.

At the R&D stage of its Revadep depressants,

Axis House is addressing the use of one of the

more controversial reagents used across the

mining industry, according to Thomas.

“At development level, the focus is to expand

the Revadep range to include selective

depressants of sulphide gangue (pyrite,

pyrrhotite) to replace or reduce the use of

hazardous reagents like cyanide,” Thomas said.

Automating cyanide control Speaking of cyanide, Orica says its Cyanide

process review and optimisation services have

recently helped a customer in Peru achieve

significant reductions in cyanide and hydrogen

peroxide consumption, all while increasing gold

recoveries.

Reducing reagent consumption offers

significant and sustainable cost benefits to

operations but comes at the risk of lower

recoveries and greater disruption to process

chemistry due to ore variability, Orica says.

This is where Orica’s process review and

optimisation service, PRO Service, comes in.

A collection of tools and services developed to

support the gold industry in achieving best

practice in gold leaching and recovery, the PRO

Service package uses tailored solutions from Orica

including the Process Health Check benchmarking

service, LeachIT™ process simulation and

Cyantific™ process analysers.

Process Health Check enables customers to

identify problem areas where improvements will

lead to significant gains in metal recoveries and

savings in reagent consumption. It uses a

customer’s historical data to benchmark their gold

solid and solution losses against similar sites

around the world. It also analyses incoming

variables, and how well they are controlled, to

produce the desired outcome – maximum

recoveries at minimum cost.

The same historical data can then be used with

LeachIT – an intelligent software package that

allows metallurgists to see how their process will

respond to changes without time-consuming and

expensive experiments. “Aimed at enabling best

practice leaching, LeachIT simulates changes to

the process and presents the impact on tails

grade,” the company said. “The software harnesses

this information not only to calculate but also

visualise gold recovery and cyanide consumption.”

Cyantific uses a range of online process

analysers to optimise cyanide addition,

detoxification processes, and tailings discharge –

lowering costs while maintaining or improving

recovery, Orica says. Customers with a properly

installed and maintained OCM5500 Leach Process

analyser typically reduce cyanide dose to the

leach by 5-20%, according to the company.

Orica’s Customer Solutions Manager – Global

Cyanide, Paul Martin, said: “We aim to take our

customers’ operations data and combine it with

our expansive global Cyanide process data

gathered over time, and then interpret that data

into insights, delivered visually so that our

customers can make more rapid and confident

decisions.”

At the open-pit gold mine in Peru, Orica was

able to demonstrate how its PRO Service enables

consumption savings and increased gold recovery.

MINING CHEMICALS

38 International Mining | MAY 2020

Orica’s PRO Service methodology

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In recent years, the mine had experienced

challenging mineralogy due to the depletion of

oxidised mineral reserves and the onset of

complex minerals.

The Process Health Check methodology was

used to analyse the site’s historical data. Among

the relevant variables that were closely scrutinised

were cyanide measurement and its dosage. It was

determined there were inconsistencies in the free

cyanide measurements due to copper variations

and sulphide levels in the ore. This variability

initially generated an overestimation of free cyanide.

It was determined that investing in an enhanced

method and frequency of free cyanide

measurement would significantly improve cyanide

control and result in a more efficient leaching

system.

Orica proceeded to implement Cyantific and its

OCM5500 Leach Process analyser. The latter

helped increase the accuracy and frequency of

free cyanide measurement, together with the

implementation of a control loop that was

integrated with the Distributed Control System of

the plant and actuators, Orica said. This automatic

dosage system was developed with the flexibility

to adjust the free cyanide set points that were

optimised for each ore type.

The automated control system managed to

significantly reduce free cyanide variability,

compared with the manual dosage, eliminating

the periods of excessive and insufficient dosage.

This resulted in a much more consistent free

cyanide level, enabling a reduction in the

consumption of reagents necessary for cyanide

destruction, which is a critical requirement for

tailings disposal, Orica said.

Once the free cyanide set point requirements

for each ore type was defined, there was a need to

have greater accuracy in the free cyanide

measurement to implement a new process control

methodology, Orica explained.

“An increased testing frequency was required to

configure the process for different operating

scenarios, which led to the integration of the OCM

5500 analyser with the control room and the

establishment of a methodology to continuously

control the leaching process,” the company said.

Throughout the project, a baseline was

established for each relevant variable, including

free cyanide concentrations before and after the

project.

The improved cyanide dosage control

successfully reduced the variability of free cyanide

in the process, according to Orica.

By adopting the automated cyanide dosage

system, the customer achieved a 40% reduction in

cyanide consumption and a more than 70% drop

in hydrogen peroxide consumption. It was

validated that gold recovery increased by an

average of 2.5% from the baseline.

Orica said: “These significant gains can be

further improved by using Orica’s LeachIT to

determine the optimum cyanide levels for various

blends of ores with different levels of copper and

sulphide minerals.

“Consistent levels of cyanide, as well as better

accuracy of the results, produces a more accurate

simulation of the leaching system and optimum

leaching conditions resulting in further gains to

customers.”

Collector development Arkema-ArrMaz, recognising a need to simplify the

flotation process and improve grades and

recoveries across the Turkey feldspar industry,

established a Joint Collector Development

program (JCDP) in partnership with a leading

feldspar producer in the country five years ago.

The JCDP took a similar approach to that of

sulphide and other industrial mineral applications,

where advanced specialty blend collectors

formulated to specific ore mineralogy have

replaced single chemical component “commodity

collectors” to efficiently and cost-effectively

provide the selectivity required, according to

Abdul Gorken, Senior Metallurgist, Arkema-

ArrMaz, and Todd Parker, Global Mining Marketing

Manager, Arkema-ArrMaz.

Gorken and Parker explained: “Arkema-

ArrMaz’s JCDP develops and evaluates potential

collector chemistries formulated for a specific ore

mineralogy with statistical mixture designs that

consider mixture stability, component

compatibility, cost and application benefits.

“Since its inception, this JCDP has successfully

completed six stages of development and

evaluation, including multiple rounds of custom-

blend collector formulation at Arkema-ArrMaz’s

lab in Mulberry, Florida, as well as confirmatory

tests and plant evaluations onsite in Turkey.

“The results of each stage are used to drive

improvements for the next in an iterative process.”

The Turkey feldspar sector was chosen as the

country’s deposits typically contain problematic

gangue minerals such as heavy

impurities (mostly rutile, titanate and

spinel), significant amounts of mica

(mostly biotite and lesser amounts of

muscovite), and varying amounts of

troublesome clays (including kaolin,

illit and more), according to Gorken

and Parker.

“Most of the heavy magnetic iron

impurities can be removed by dry and

wet, high- and low-intensity magnetic

separators,” they said. “However, the

remaining heavy impurities consisting

mainly of rutile, non-magnetic iron

and mica require special reverse

flotation techniques for removal before acceptable

feldspar concentrate grade can be achieved.”

In the early 1990s, some major local feldspar

producers introduced a reverse flotation technique

whereby heavy impurities were floated away with

fatty acids first, after which mica was floated away

with amines in acidic media.

Later, with the development of more efficient

fatty acid collectors, the same or better separation

was achieved in a neutral flotation circuit using

more environmentally friendly processes, Gorken

and Parker explained.

Then prina oil, a residue from local olive oil

production, became the standard fatty acid

replacement. In the mid-2000s, with the

development of more selective fatty acid types

and amines, further grade and recovery

improvements were realised.

“Today, however, with the rapid growth of

Turkish feldspar production and the gradual

decline of higher-grade deposits, better flotation

concentration methods are needed,” Gorken and

Parker said. “Feldspar producers and suppliers

alike are seeking flotation improvements in

selectivity, processing cost and simplicity with

specially formulated fatty acids and amines.”

When floating feldspar, de-sliming followed by

two stages of flotation with two different

collectors are usually required to produce

acceptable product quality, according to Gorken

and Parker. The typical feldspar beneficiation

process involves:

n Grinding, classification, screening, cycloning;

n Magnetic separation; and

n Froth flotation:

n Direct flotation of feldspar – practiced on

feldspar ores with high quartz content; or

n Reverse flotation of feldspar – practiced

on feldspar ores with small amounts of

quartz.

Anionic collectors (typically fatty acids and their

soaps) make up 80% of industrial mineral

collectors and are considered analogous to

xanthates in sulphide flotation, according to

Gorken and Parker. “These collectors are used in

direct flotation of minerals with positive surface

MAY 2020 | International Mining 39

MINING CHEMICALS

Arrkema-ArrMaz’s CustoFloat custom blend collectors yielded substantial performance improvements and a much simpler single-stage process in feldspar operations in Turkey

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40 International Mining | MAY 2020

charges such as calcite, phosphate and fluorspar;

and in reverse flotation of heavy impurity minerals

from feldspar and other similar industrial

minerals.”

“Commodity” fatty acids are currently the most

widely used collector type in reverse feldspar

flotation due to the absence of better alternatives,

according to Gorken and Parker, but they come

with poor selectivity, high dosage requirements

and associated operational difficulties, such as

equipment smearing and the need for collector

removal from concentrates for specific

applications, Gorken and Parker said.

Due to these issues, modifiers have been

introduced to enable continued use of fatty acid

collectors, further complicating the flotation

process and increasing costs, Gorken and Parker

said. “Therefore, it is imperative that new, more

efficient alternatives to century-old fatty acids be

developed.”

This led to the development of the JCDP, which

has seen the typical two-stage reverse feldspar

flotation process simplified to a single-stage

process in Turkey – an industry first, according to

Gorken and Parker.

“Arkema-ArrMaz’s CustoFloat® custom blend

collectors specifically formulated to the producer’s

unique ore mineralogy yielded substantial

performance improvements,” they said. “Collector

dose was reduced by 30-50%, and significant

increases in recovery and grade were observed.

Both collectors improved overall operational

efficiency and cost-performance considerably,

while streamlining reagent dosing and handling.”

The custom blend collectors developed under

this JCDP provided enhanced capacity utilisation;

improved flotation efficiency; better feldspar

recovery and concentrate grade; simpler and

easier application compared with current industry

standards; improved flotation selectivity; better

material handling; and regulatory

compliance/cost avoidance, according to Gorken

and Parker.

The JCDP also showed collaboration between

mineral processing operations and reagent

formulators to develop tailor-made collectors

yields better results compared with commodity

collectors, Gorken and Parker remarked.

Dewatering concentrate Dewatering and water reuse/recycling are

influencing not only OEM and mineral processing

equipment design; they are also impacting the

development of chemicals.

According to Clariant, mining operations have

been demanding increasingly challenging

operational targets for the dewatering process,

requiring lower humidity for concentrates.

The Clariant Mining Solutions’ applications

technologies team in Brazil has developed, in

conjunction with one of its iron ore customers, a

novel dewatering agent that, it says, specifically

targets sinter feed piles and iron flotation

concentrate.

Laboratory drainage tests using the FLOTICOR

dewatering agent on iron ore sinter feed reported

a potential improvement in moisture reduction of

10.2%, according to Clariant. In a subsequent field

trial, a relative reduction of 10.5% moisture (1%

absolute) was achieved (as is shown in the photos

right).

The amount of water that was dewatered on the

sinter feed pile versus the control pile that did not

have the dewatering agent is also emphasised in

the photos.

Clariant said the dewatering agent is under

further field trial evaluation ahead of future, more

formal test work.

“Dewatering of iron ore flotation concentrate

has been conducted by the Clariant Mining

Solutions team in Brazil and preliminary

indications are that moisture content can be

reduced by 2% under laboratory lead filtration

testing,” the company said.

Additional confirmation testing for operational

qualification is being carried out and will lead to

industrial trials later in 2020, according to Clariant.

Addressing crud and scale On top of improving mineral processing using

novel chemicals, Solvay’s customers are looking to

it to both extend the life of processing equipment

and improve said equipment’s effectiveness.

Its ACORGA® CR60 series reagents are

processing aids designed to help solvent

extraction operations reduce crud formation from

turbidity in leach solutions (patent-pending). They

have also been found to improve phase separation

in solutions with high colloidal silica, according to

Solvay.

Its MAX HT® sodalite scale inhibitor,

meanwhile, is a “best-in-class” product that

eliminates sodalite scale from heat exchangers

throughout the Bayer Process and contributes to

the sustainability of the alumina industry,

according to the company.

A liquid reagent, ACORGA CR60 affects the

formation of the solid-stabilised organic/aqueous

emulsion and therefore significantly reduces – and

in many cases stops – crud formation, Solvay

explained.

In a six-month (pilot and commercial) trial with

Lisbon Valley Mining Company at its copper

operation in Utah, USA, the following benefits

were demonstrated at the solvent extraction

operation, according to paper given by Solvay at

the 2020 SME Annual Conference and Expo:

n Minimum levels of crud were maintained at

extraction stages, without the need for crud

pumping and processing from the stages;

n ACORGA CR60 eliminated plant “upsets” and

the need for flow rates reduction against

increased turbidity events (ore curing, raining

events, pad challenges, etc);

n As a result of the reduced crud levels, pregnant

leach solution throughput increased 7%

throughout summer and winter seasons; and

n No impact on downstream processes such as

electrowinning and leaching.

Solvay says its MAX HT scale inhibition

technology has benefited global alumina

refineries for over a decade by improving

operating efficiency, saving energy costs, reducing

carbon footprints and lowering freshwater usage.

It has only recently been introduced to China’s

alumina industry, leading to some impressive

results.

Solvay explained: “China produces over half of

global alumina output, and the industry has a

rapidly growing need to improve efficiency and

reduce its environmental impact, as competition

intensifies and more stringent regulations are

being enforced.”

This has led the industry to adopt new

technologies in order to compete on a global

stage and reduce its environmental footprint.

The introduction of MAX HT, Solvay says, has

provided “outstanding scale inhibition

performance in the liquor evaporation process” in

China.

With MAX HT, it’s estimated that some 0.03 t of

steam for evaporation can be saved, on average,

for every 1 t of alumina produced (fresh water is

heated to produce steam for evaporation. Thus,

with MAX HT, fresh water, as well as the energy

and resultant CO2 associated with steam

production, are reduced).

So far, Solvay’s scale technology has been used

at over 30 evaporation lines in Chinese alumina

refineries, bringing significant economic benefits

to refineries, while contributing to reducing their

environmental impact, it said.

MINING CHEMICALS

A field trial in Brazil of Clariant Mining Solutions’ novel FLOTICOR dewatering agent led to a 10.5% moisture (1% absolute) reduction in iron ore sinter feed

IM

MINING CHEMICALS.qxp_proof 29/04/2020 09:44 Page 5

/ColorImageDict > /JPEG2000ColorACSImageDict > /JPEG2000ColorImageDict > /AntiAliasGrayImages false /CropGrayImages false /GrayImageMinResolution 300 /GrayImageMinResolutionPolicy /OK /DownsampleGrayImages true /GrayImageDownsampleType /Bicubic /GrayImageResolution 300 /GrayImageDepth -1 /GrayImageMinDownsampleDepth 2 /GrayImageDownsampleThreshold 1.03333 /EncodeGrayImages true /GrayImageFilter /DCTEncode /AutoFilterGrayImages true /GrayImageAutoFilterStrategy /JPEG /GrayACSImageDict > /GrayImageDict > /JPEG2000GrayACSImageDict > /JPEG2000GrayImageDict > /AntiAliasMonoImages false /CropMonoImages false /MonoImageMinResolution 1200 /MonoImageMinResolutionPolicy /OK /DownsampleMonoImages true /MonoImageDownsampleType /Bicubic /MonoImageResolution 1200 /MonoImageDepth -1 /MonoImageDownsampleThreshold 1.08333 /EncodeMonoImages true /MonoImageFilter /CCITTFaxEncode /MonoImageDict > /AllowPSXObjects false /CheckCompliance [ /None ] /PDFX1aCheck false /PDFX3Check false /PDFXCompliantPDFOnly false /PDFXNoTrimBoxError true /PDFXTrimBoxToMediaBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXSetBleedBoxToMediaBox true /PDFXBleedBoxToTrimBoxOffset [ 0.00000 0.00000 0.00000 0.00000 ] /PDFXOutputIntentProfile (Coated FOGRA27 \050ISO 12647-2:2004\051) /PDFXOutputConditionIdentifier (FOGRA27) /PDFXOutputCondition () /PDFXRegistryName (http://www.color.org) /PDFXTrapped /False

/CreateJDFFile false /Description > /Namespace [ (Adobe) (Common) (1.0) ] /OtherNamespaces [ > /FormElements false /GenerateStructure false /IncludeBookmarks false /IncludeHyperlinks false /IncludeInteractive false /IncludeLayers false /IncludeProfiles true /MarksOffset 8.503940 /MarksWeight 0.250000 /MultimediaHandling /UseObjectSettings /Namespace [ (Adobe) (CreativeSuite) (2.0) ] /PDFXOutputIntentProfileSelector /UseName /PageMarksFile /RomanDefault /PreserveEditing true /UntaggedCMYKHandling /LeaveUntagged /UntaggedRGBHandling /UseDocumentProfile /UseDocumentBleed false >> > ]>> setdistillerparams> setpagedevice