MINING CHEMICALS
At Bulyanhulu Gold Mine , the GlyCat pilot program has led to an 80 % reduction in cyanide consumption while achieving gold recoveries that are comparable with traditional cyanidation , Draslovka says
reduction in processing costs of 25 %, rising to 50 % for some more complex ores ”, the company adds .
Pavel Bruzek Jr , CEO of Draslovka , said of the Barrick news : “ I look forward to continuing to
work with Barrick and am confident others in the sector will soon see that GlyCat is revolutionary and its development will enable a major shift for the gold mining industry through massive economic and environmental benefits .”
Simon Bottoms , Barrick Mineral Resource Management & Evaluations Executive , said : “ The application of GlyCat technology within our operations has significant potential to deliver improved operational efficiencies and cost savings , whilst also improving our environmental legacy . Consequently , we are very pleased to embark upon this strategic partnership with Draslovka to take advantage of this innovative technology across our global operations .”
CLEVR gold leaching
Dundee Sustainable Technologies ( DST ) believes it has developed a viable cyanide-free leaching reagent for the gold mining community under its CLEVR Process™ .
This process uses a 2 % bleach solution in leaching kinetics , the chemical reaction that separates gold from ore , to , the company says , release gold within a couple of hours versus the 36 hours or more in traditional cyanide leaching .
The Quebec-based company has engaged Newmont , the world ’ s largest gold miner by production , to test out its CLEVR thesis , with the two companies signing a Technology Transfer Licensing Agreement for the use of the process all the way back in 2020 .
Following a successful test work program in the March quarter of that year , Newmont expressed its interest in the execution of such an agreement , allowing the gold miner to conduct laboratory CLEVR leaching tests in its technical facilities in Englewood , Colorado .
The two companies are now working on a selected project in a jurisdiction where cyanide has been banned .
In DST ’ s September quarter Management Discussion & Analysis , it said : “ Newmont is the owner of a gold project with significant resources that cannot go into production due to cyanide restrictions . DST is developing a project with Newmont in which DST could provide a pilot plant for an on-site demonstration of the technology .
“ The approval of such a piloting program would represent a breakthrough for the CLEVR Process and could significantly accelerate other commercialisation opportunities .”
The closed-loop CLEVR Process could potentially allow mine operators to reduce reagent use and cost , as well as lower the cost , risk and environmental impact associated with gold mining .
Besides no cyanide , the process produces no toxic liquid or gaseous effluent , and the solid residues are inert , stable and non-acid generating , according to the company .
The CLEVR Process uses sodium hypochlorite , not chlorine gas , with a catalytic amount of sodium hypobromite in acidic conditions to put the gold into solution , according to the company . Contact time is short , carried out at ambient temperature and pressure , and all chemicals are recycled within the circuit . If needed , sea water may also be used , DST says .
Gold extraction yields have been seen at more than 95 % while capital and operating costs are competitive with traditional processes , the company claims .
DST said on CLEVR developments : “ The corporation is working with several properties in Asia , South America , Africa and Canada to test their ores and concentrates using the CLEVR Process .”
The company also offers its trademarked
GlassLock Process™ to help the industry remove and stabilise arsenic .
This process , too , has been gaining admirers with DST having entered a Technology Framework Agreement with Hatch for the use of the technology in combination with Hatch ’ s fluid bed roasting and arsenic dry scrubbing technologies on gold and arsenopyrite projects .
The GlassLock Process turns arsenic into glass through vitrification , integrating it in a mixture of common reagents such as silica , recycled glass and hematite . The arsenic compounds are stable , permanent and insoluble within a glass product , providing greater stability , DST says .
In addition to Hatch , the company has received mandates from both an operating base metal smelting facility in Africa to perform the basic engineering phase for a full-scale GlassLock implementation on site , as well as a mandate for detailed engineering for another industrial implementation of the process in Ghana – with a “ top tier gold producer ” looking to leverage GlassLock as part of its legal obligation to maintain its mining permit .
Reagent-based solutions under a new name
Having successfully spun off from Solvay , Syensqo is now ready to showcase its frontrunner credentials in providing sought-after chemicals to the mining sector on a global scale .
Syensqo ’ s mining business has a rich legacy , dating as far back as American Cyanamid Company and Cytec , prior to Solvay . Today , Syensqo provides mining operations worldwide with a wide range of reagent-based solutions designed for more efficient and effective mineral processing , solvent extraction and alumina processing . The flagship products within Syensqo ’ s flotation portfolio include collectors such as AEROPHINE ® and frothers such as OREPREP ® . It also offers depressants such as ACCO-PHOS ® , and dispersants like CYQUEST ® . In addition to equipment and operations improvements , mines are now exploring novel continuous improvement strategies with the help of Syensqo focused on real-time , reagent-based formulation and process optimisation .
This is mainly through Syensqo ’ s SmartFloat™ , a platform that offers real-time flotation reagent improvement recommendations ; the Syensqo Cube , which then executes real-time formulation ; and SolvExtract ® , a platform that provides continuous operational improvement suggestions to copper solvent extraction customers .
The result is tailored formulations , better
dosing and , ultimately , better mineral recovery , all while reducing water and energy inputs for improved mining productivity .
Matthew Davis , Global Business Director for Syensqo ’ s flotation and solvent extraction
52 International Mining | MAY 2024