REPROCESSING & RETREATMENT
It has proven out the technology at PT Agincourt Resources ’ Martabe gold-silver operation in Sumatra , Indonesia , while it is in the final stages of going live with another ReCYN installation at Endeavour Mining ’ s Ity gold mine in Côte d ’ Ivoire .
GreenGold could potentially detoxify the tailings stream and clean up the water discharge at Mount Morgan . This would be a boon for the Department of Natural Resources , Mines and Energy , which currently treats the water from the open-pit and tailings deposits at Mount Morgan before it is released into the local creek due to the low pH levels caused by the acid-forming pyrite .
The ReCYN resin plant , GreenGold says , can deal with the higher cyanide consumption needed to treat the copper at the back end of the Mount Morgan flowsheet . This will allow Heritage to focus on the gold – which represents 90 % of revenue – that can be processed by a carbon-inleach plant .
The DFS anticipates a one-year payback and an upfront capital expenditure bill of A $ 74 million for the project .
Orica ’ s Cyclo goes commercial
Coming under a different retreatment guise is Orica ’ s Cyclo™ solution for used oil .
Last month , the company announced it had successfully commissioned an automated used oil recycling service that , it says , enables treated used oil from mine sites to be used in the manufacture of quality emulsion for bulk explosives , reducing waste , cost and risks for customers and impact to the environment .
Mine sites where Orica ’ s site-based emulsion plants are located can now realise the benefits of Cyclo – a process that allows customers to transform used oil from heavy machinery into raw material for the manufacture of high-quality bulk explosives . When used in combination with Orica ’ s proprietary emulsifier technology , Cyclo offers customers a high-quality bulk explosive product , while reducing cost and risk associated
Delivering environmental and commercial benefits to customers , the fully containerised and automated Cyclo system is capable of treating up to 1,000 litres of used oil per hour with the disposal of used oil , it says .
Delivering environmental and commercial benefits to customers , the fully containerised and automated Cyclo system is capable of treating up to 1,000 litres of used oil per hour and is estimated to reduce up to 800,000 litres in diesel consumption annually per site for customers .
Orica ’ s Chief Technology Officer , Angus Melbourne , said : “ Cyclo is an example of how we are constantly looking for ways to reduce the carbon footprint for our customers and Orica , while creating value to stakeholders . The benefit of the Cyclo service is its ability to fully integrate into our on-site emulsion plants , enabling used oil from the mine to be directly recycled without leaving the site .”
Locations where Cyclo has been implemented have realised a reduction in diesel consumed in the production of bulk explosives by up to 50 %, according to Orica . Additional environmental benefits to customers are delivered by reducing heavy vehicle movements through local communities and reducing carbon dioxide emissions through transport .
Cyclo units are currently installed across several customer sites in Africa and Asia / Oceania – including in Ghana . Further installations in Latin America and more sites across Africa are slated for completion by the end of the year , while a version to suit arctic conditions is being developed for Canada , China and Mongolia .
Geofoam on the rise
Auxilium Technology Group ( ATG ), a start-up connected to the University of Arizona , was recently announced as one of two finalists in the BHP Tailings Challenge , an international competition to promote the development of new technologies to reuse mine tailings .
Last year , ATG , in collaboration with Metso Outotec , became one of 10 companies and academic research groups chosen to move on to the laboratory stage of the BHP Tailings Challenge , from an initial field of 154 applicants from 19 countries . For the next phase of the challenge , ATG plans to build a pilot tailings processing plant at the
Metso Outotec supported the ATG process design concept for the BHP Tailings Challenge by estimating engineering costs and providing plant solutions technology competence
San Xavier Underground Mining Laboratory , owned by the University of Arizona . Metso Outotec will contribute with advice on engineering and scale up using its products .
To perform the tasks at hand , BHP has awarded each of the teams $ 300,000 , in addition to support from the BHP Team , Expande and Fundación Chile .
The proposal from BHP aims at maximising value from waste streams while minimising the environmental footprint of the mining industry .
ATG said : “ The main goal of this phase of the challenge will be to perform a pilot under a controlled environment of the Entail Circuit . Entail treats and repurposes every tailing component generating products like green hydrogen , purified water , reagents for mining , biogas , additives for the cement industry and our unique Geofoam .”
The new tailings Geofoam solution can used as a support material for the construction industry and as an insulator , according to ATG , aiding world emission goals to decrease the carbon footprint by reducing GHG emissions and providing energy savings
More recently , ATG made plans to produce specialty products from tailings such as ultrapure silica and direct reduced iron .
At the end of the BHP Tailings Challenge , one or both of the selected teams will be awarded a total of $ 8.6 million for efforts leading to an industrial pilot plant at a site selected by BHP .
Metso Outotec supported the ATG process design concept by estimating engineering costs and providing plant solutions technology competence . The concept considers pre-designed plant units known as “ process islands ” for almost all the process areas of the future plant , the company said . Support also included input on optimal equipment sizing to optimising engineering costs and modularising the plant to meet future capacity requirements .
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APRIL 2023 | International Mining 63