IM MAR 23 March 2023 | Page 20

COPPER PROCESSING
may use up to 40 % less energy than traditional technology in a regrind application , for instance .
Yet , Metso Outotec , as its Planet Positive focus outlines , has made significant improvements in energy efficiency at every stage of the mining process . The use of its latest large TankCell ® , for example , comes with reduced energy requirements of up to 20 % over the standard flotation benchmark .
Beyond simply energy efficiency in copper processing , the company contributes to lower GHG footprints in several other ways , according to Guyot , entailing consumable wear parts that have significantly longer lifetimes and recycling options ; reduced equipment footprint alternatives that come with less infrastructure requirements ; and a supply chain decarbonisation plan that leads to lower embedded carbon and Scope 3 emissions associated with its products .
On the metallurgical processing side , Kim Fagerlund , VP of Metals R & D , says the current trend of copper producing plants using higher capacities for economies of scale is also having a direct impact on efficiency and , therefore , the energy used to process the red metal .
“ Metso Outotec ’ s Flash Smelting and Flash Converting Process , together with LUREC ® high concentration sulphur dioxide processing , meanwhile , is the cleanest copper smelting method available ( up to 99.9 % of sulphur can be captured ),” he told IM . “ In addition to sulphur capture , more than 1.2 Mt / y of CO 2 emissions were avoided in our customers ’ operations by applying our copper flash smelting , measured against industry baselines and the actual saved emissions depending on the annual production volumes .”
Yet , getting the industry to apply sustainable solutions today still requires a dedicated approach from the mining supplier community that showcases the benefits over the full life of operation .
Metso Outotec ’ s Planet Positive portfolio , which currently consists of some 130 products and services , has been designed to do exactly this .
Marius Verwoerd , VP of Sustainability , explained : “ Our Planet Positive portfolio is products and services that are significantly better than the market-standard equivalent – we have quantified this , and use the Planet Positive label to communicate to our customers that these products can make a meaningful contribution to their sustainability goals ; this is very often based on carbon intensity .”
The company is currently working on providing embedded carbon calculations to mine sites on a case-by-case basis , but it is already able to highlight how a combination of Planet Positive solutions – not just individual items – can provide the compounded impacts the industry needs to meet its 2030 , 2040 and 2050 goals .
It can do this through a simulation tool that leverages the Geminex™ digital twin platform to calculate the environmental footprint of a flowsheet ( energy , CO 2 , water ) together with the capital and operating expense impact . Such integrated modelling ensures that a reduction in carbon emissions at the front end does not translate to , for example , more fines generation in the tailings dam .
Guyot explained : “ With this powerful calculator , primarily developed for low-grade copper mines , we have a unique tool to engage our customers in the cost / benefit tradeoffs and assess all sorts of Planet Positive flowsheet options and how they can benefit our customers ’ operations .
“ It ’ s not just putting individual solutions in the plant – it is about showing the interlinked benefits throughout the mine site .”
This was displayed in a recent award for crushing , screening and grinding technologies to a greenfield iron ore project in South America , which saw the company ’ s HRC™e high pressure grinding rolls and Vertimill ® grinding mills included in the same flowsheet . By using this design , the plant is expected to save up to 25 % of installed power compared with a conventional HPGR / ball mill circuit and over 40 % compared with a conventional SABC circuit , the company claims .
These compounded benefits will ultimately be needed to tackle the challenges the industry is facing , according to Verwoerd .
“ To set the context , part of the challenge is that the climate transition needs an increase in supply of copper ,” he said . “ This , in turn , means developing more complex orebodies , and very often lower-grade orebodies . You have to improve your performance and run faster to stay in one place .
“ Within that context , technology and innovation is going to be an important part of solving that challenge .”
On the metallurgical side , Metso Outotec is well equipped for this , according to Fagerlund , who highlighted the company ’ s advances in processing high arsenic containing concentrates in Chile .
“ You always need to look at the ore itself to select a suitable process ,” he said . “ Luckily , we have the capabilities to do this – we have our own research centres , testing facilities and internal benchmarks that have been verified . We then have the options to act on these suggestions with full flowsheet design capabilities .”
Metso Outotec continues to work on “ disruptive technologies for the future ”, but it is cognisant the normal timelines associated with market adoption and the need to bring on more copper supply in line with the climate transition makes it tricky to affect the emission ambitions set for the next decades .
“ Copper production growth and net-zero copper production is expected within a relatively short horizon ,” Guyot said . “ This means that the priority is towards modernising or upgrading existing operations and to build the next processing plants based on the best available technology today .”
Ore sorting is one avenue the company is pursuing through collaboration with sensor technology companies able to retrofit these on in-pit crushing and conveying or “ early-crushing ” stage processes .
Another development is “ coarser flowsheets ” able to reduce the amount of energy used and take a more “ surgical ” approach to targeting ore , not waste , in the comminution process . Coarse particle recovery technology is one specific focus area here .
Then there is the use of alternative fuels in the copper reduction process , such as hydrogen , as Fagerlund acknowledged .
The company is convinced that now is the right time to crystalise these technology and process developments given the state of flux present in the copper market .
Verwoerd concluded : “ This is not us trying to push the market in a direction it doesn ’ t want to go ; our customers have sustainability objectives and are subject to many pressures from stakeholders to reduce their footprint .
“ In that regard , if we are pushing a door , it is very much an open door .”
Learnings in the leach pad
Back in November , BASF and Moleaer™ announced an exclusive partnership to combine expertise in mineral processing , hydrometallurgy , gas transfer and nanobubble technology to develop what they viewed as innovative processes for mining .
The initial aim was to target the copper leaching process and improve extraction rates of copper ores containing high levels of chalcopyrite , which have historically been difficult to leach .
The pair viewed the combination of Moleaer ’ s nanobubble technology to improve the extraction process of copper and BASF ’ s LixTRA™ reagent as offering “ compounded ” mineral recovery rates and efficiencies , especially in sulphide-based ores such as chalcopyrite .
LixTRA is a liquid surfactant added in small ( parts per million ) quantities to the irrigation system of the leaching process . It is nonhazardous , low foaming and fully compatible with downstream solvent extraction / electrowinning ( SX / EW ) processes and does not
18 International Mining | MARCH 2023