WORLD PROSPECTS
valves , electricals and components ). They have 100 plates each but are expandable to 130 . Diemme also supplied similar filter presses for two of Alcoa ’ s Australian alumina refinery sites which are in Kwinana and Pinjarra , both in Western Australia . Alcoa was the first major alumina producer in Australia to use residue filtration .
Filter press technology has advantages that make it particularly suitable for bauxite residue treatment . Compared to other technologies , filter presses allow drier residue ( with residual moisture lower than 30 % w / w ). As a consequence , the material handling characteristics of the cake obtained by using filter presses Diemme argues are far better than results achieved by alternative methods .
In Brazil , Alcoa has three production units , in Poços de Caldas ( MG ), São Luís ( MA ) and Juruti ( PA ), as well as offices in São Paulo ( SP ), Poços de Caldas ( MG ) and Brasília ( DF ), in addition to a significant shareholding in bauxite miner Mineração Rio do Norte ( MRN ) and in four hydroelectric plants : Machadinho , Barra Grande , Serra do Facão and Estreito .
“ Re-defining what it means to be the most sustainable upstream aluminum company requires a deep commitment to continuously improving our footprint and a relentless pursuit of innovation that will help us progress ,” said John Slaven , Alcoa Executive Vice President and Chief Operations Officer last year . “ By continuing to roll out this bauxite residue filtration technology across more of our refineries , we continue to set new benchmarks in regard to resource management while making progress on goals aligned with our Advance Sustainably strategic priority .” www . aqseptence . com ; www . alcoa . com
TOMRA helps Renison hit records
TOMRA Mining and its sensor-based sorting technology has , the company says , helped unlock significant value and environmental benefits at the Bluestone Mines Tasmania JV ( BMTJV ) Renison tin mine in Tasmania , Australia .
Renison comes a mining rate of close to 1 Mt / y , but the concentrator is restricted to 750,000 t / y , according to TOMRA .
The underground mine operates a primary crushing system before the material is transported to the surface through a shaft . Once there , it enters the pre-concentration plant , where it undergoes a three-stage crushing , screening and cleaning process . The particles are split into two fractions – 10-25 mm and 25-60 mm – which are fed into two TOMRA XRT sorters . The output
CMIC launches ReThinkMining Ventures
The Canada Mining Innovation Council ( CMIC ) has announced the launch of ReThinkMining Ventures Inc ( RMV ), a forprofit subsidiary of CMIC .
Established to commercialise the technology in which CMIC is directly vested , ReThinkMining Ventures will help accelerate the development and deployment of new technology that will address critical needs of the mining industry , CMIC said .
CMIC ’ s goal is to reduce the mining industry ’ s energy use , water use and environmental footprint by 50 %, by 2027 . It has been working with major global players in the move toward zero waste mining , striving to develop technologies and innovations that will reduce consists of two streams : the product , which is transferred to the wet plant , and the waste , which is fed into a TOMRA EM sorter to separate acidforming sulphides from this waste stream .
In the wet plant , the product goes through primary grinding followed by bulk sulphide flotation . The tailings are processed downstream to concentrate the cassiterite tin mineral through gravity concentration ; gravity tails are further treated via desliming and tin flotation . The combined concentrates are fed to a leaching circuit to remove carbonate minerals . After a final wash stage , the concentrate is de-watered and dispatched .
BMTJV approached TOMRA to address two key requirements at the plant . The first was the need to upgrade the tin feed to the plant . The second was to address the environmental issue of removing acid-forming sulphides from the waste .
TOMRA proposed a solution that addressed the tin feed quality with two COM Tertiary XRT 1200 sorters and the waste issue with a COM Tertiary EM 1200 sorter .
The two COM Tertiary XRT 1200 sorters went into operation in 2018 . Initially , BMTJV ’ s strategy focused on low reject grades ahead of the mass
waste , lower costs and mitigate environmental impacts across all aspects of mining .
The CMIC approach to these and other
challenges is to start by developing technology roadmaps that align the industry on common
challenges , and also help create a paradigm shift in terms of what is possible . At the tactical level , CMIC creates teams , or consortia , of mining reject rate and overall process plant throughput . However , the specific conditions at the Renison mine affected the results achieved . The large variance in run of mine particle size distribution resulted in insufficient stability in the feed to the circuit . In addition , the wet conditions and consequent high ambient moisture content , combined with the high moisture of the ore delivered from underground , further affected the sorting process .
In 2019 , a new investigation was conducted into the ore sorting performance and led to a change of direction , where the operation shifted away from targeting low reject grades , towards sorting as aggressively as possible for mass reduction .
This approach was best for Bluestone ’ s application as it provided the ability to process 15- 20 % more tin units without having to upgrade the downstream concentrator , which has led to multiple production records and the unit cost per tonne of tin produced reducing by almost 10 %.
Since then , BMTJV has upgraded the ore sorting circuit with two new XRT models with stainless steel internal parts and advanced features such as the TOMRA ACT user interface and the TOMRA Insight cloud-based platform , according to TOMRA . www . tomra . com ; www . metalsx . com . au
companies and suppliers to co-develop new technology , and also co-develop the implementation of new technology .
Mark Thorpe , CEO of EnviroGold Global and Chair of CMIC ’ s Board of Directors , said : “ This is a major , positive advance for the CMIC . As the Chair of the Board of Directors , I congratulate the entire team on achieving this milestone . We are ready to complete the work to start the commercialisation of the exciting projects that are in the CMIC project pipeline , which has been our long-term goal .”
Carl Weatherell , CMIC Executive Director and CEO , added : “ The creation of ReThinkMining Ventures is part of the natural evolution of CMIC and fills a serious void in the mining innovation ecosystem .” www . rethinkmining . org
8 International Mining | FEBRUARY 2022