MINING CHEMICALS
A dose of reality
Effective use of chemicals makes the mineral processing world go round . Dan Gleeson looks at the latest from this market , including some alternatives to reagents with significant mining legacies
The mining sector ’ s use of chemicals is always under the spotlight , with many of the negative perceptions aimed at the industry stemming from documented cases of operators ’ irresponsible use and control of reagents .
The community is putting significant effort into changing these perceptions , whether it be through looking at alternative reagents , investing in new mechanisms to reduce the dosages required of certain chemicals , or ensuring on closed loop systems that reduce contamination risk . In addition to environmental , health and safety benefits , many of these activities could lead to lower costs .
Some of these aims will be achieved sooner than others , however cyanide currently remains the best way to chemically extract gold from ore on a commercial basis . This was made abundantly clear earlier this year when Orica acquired 100 % of Cyanco for $ 640 million .
The addition of Cyanco , a US-based leader in the manufacture and distribution of sodium cyanide primarily serving the gold mining industries in the US , Canada , Latin America and Africa , was seen as complementing Orica ’ s established Mining Chemicals business and creating an integrated global manufacturing and distribution network .
After completion , it is expected to result in the establishment of an Orica Mining Chemicals business vertical and the creation of an integrated global sodium cyanide manufacturing and distribution network , the company said .
The move more than doubles Orica ’ s existing sodium cyanide production capacity from Yarwun , Australia , to approximately 240,000 t / y through the addition of Cyanco ’ s two manufacturing plants in Nevada and Texas , USA , to Orica ’ s sodium cyanide business . Orica said these plants also significantly increases Orica ’ s footprint in the attractive North American gold mining industry . In addition , the assets are strategically located to access cost-competitive US natural gas-based manufacturing assets .
Orica Managing Director and CEO , Sanjeev Gandhi , said : “ Cyanco is a highly complementary business and , by combining it with our established sodium cyanide business , Orica will create a leading integrated global sodium cyanide producer with world-class supply capabilities in mining .”
He adds : “ By combining these two leading businesses , we expect to improve our ability to serve our customers by enhancing Orica ’ s global network of transfer stations in key gold mining regions , supporting security of supply to mine sites .”
Orica said it offers a complementary geographic expansion into attractive US and Canada gold mining industries , with longterm industry trends driving demand for sodium cyanide .
The company referenced data on expected global sodium cyanide demand growing at circa-4 % per annum from 2023 to 2028 , with North American sodium cyanide demand surpassing this at
Image left : Syensqo claims Transfoamer frother technology brings the “ first true innovation ” to frothers in more than six decades
growth of circa-5 % per annum in the same period .
“ Global treated ore is forecast to grow faster than historic rates due to greenfield and brownfield mining projects and decreasing ore grades ,” it added .
Barrick moves to commercialise GlyCat use
Still in the cyanide camp , Draslovka a . s ., a provider of sustainability-led technologies , reagents and services for mining and the energy transition , recently announced the start of commercial use of its glycine leaching technology for gold , GlyCat™ , at Barrick Gold ’ s Buylanhulu operation , in Tanzania .
This announcement came alongside the news that Draslovka and Barrick ’ s strategic partnership was being expanded to include a broader testing program in 2024 that will span multiple mine sites .
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 . With GlyCat as part of the process , the mine ’ s tailings have shown undetectable levels of weak acid dissociable cyanide , thereby reducing detoxification requirements and costs .
GlyCat , Draslovka says , will enable a major shift for the mining industry ’ s sustainability profile by substantive replacement of cyanide used in processing of gold ores with a non-toxic , food-grade reagent that is recyclable .
“ Depending on the type of ore , using GlyCat in existing leaching circuits allows for a 20 % to 80 % reduction in cyanide usage while reducing or entirely eliminating cyanide detoxification requirements ,” it says . “ In select ores , the process also results in higher recoveries .” GlyCat “ can potentially achieve an average
Aerial image of Orica ' s manufacturing facility at Yarwun , Queensland
50 International Mining | MAY 2024