COMMINUTION & CRUSHING
Closing in on the MissionZero Mine
FLSmidth , fresh from its acquisition of thyssenkrupp ’ s Mining division , is bringing a process-first and full-flowsheet perspective to any crushing and comminution discussions it has with mining clients .
“ This ranges from selecting the right equipment for the application ( eg dimensioning and capacity , operational and performance requirements , etc ) to technology upgrades and retrofits ( eg newer , more advanced equipment models ),” the company told IM .
FLSmidth has had its MissionZero aims in place since November 2019 . These centre on an ambition to provide zero-emission technology to the mining and cement industries by 2030 , enabling a potential 10 % reduction in the world ’ s CO 2 emissions .
The company sees the recent expansion of its crushing and comminution product offering with the incorporation of thyssenkrupp ’ s Mining division potentially accelerating these aims .
“ This is because the acquisition strengthens FLSmidth ’ s position in HPGR applications and expands our installed base and offering , opening up opportunities for dry finish grinding and new equipment , such as the ERC ® Eccentric Roll Crusher ,” it said . The ERC , released in 2019 by tk Mining , fits into FLSmidth ’ s range of jaw crushers and large gyratory crushers with its ability to accept large rocks and produce a suitably sized product for conveying and secondary crushing or , if applicable , directly to tertiary crushing .
“ In addition , the company ' s focus on ecobeneficiation , water and tailings management , and digital solutions are all geared towards achieving sustainable productivity and reducing water and energy waste ,” FLSmidth said .
While the type of ore being processed obviously dictates the selection of comminution equipment , FLSmidth says it has observed “ significant ” energy reductions of up to 30 % in the lithium / spodumene flowsheet it is currently developing . In this particular example , the OEM is looking at using a stacked ABON ® sizer system in conjunction with its OK™ Mill technology .
“ Additionally , we believe that the energy consumption could be further reduced by adding the ERC crusher to the circuit ,” it said .
When it comes to copper-based comminution circuits , the company is weighing up its coarseAIR™ coarse particle flotation ( CPF ) technology as a central part of its MissionZero Mine .
While dependent on the type of ore being processed , this technology could enable FLSmidth to reduce grinding circuit energy , minimise raw material requirements , produce coarser tailings , and decrease the footprint of the flotation circuit and solid-liquid separation .
The resulting coarse concentrate requires regrinding before further flotation to achieve required grades in the final concentrate , according to the company , with FLSmidth saying it offers two technologies for modern regrind circuits : the FTM , a vertical agitated steel media mill , and the VXPmill , a vertical stirred ceramic media mill .
“ Both are proven to reduce energy and grinding media consumption when compared to horizontal ball mills for the same grinding duty , while also significantly reducing mill footprint and concrete foundation mass ,” it said .
The company plans to back up these assertions with an inconstruction dry grinding VRM test facility in Salt Lake City , Utah , as well as the ability to leverage its finish grinding testing capabilities in Europe .
Additionally , FLSmidth is working on developing comminution flowsheets for both wet and dry applications that , it says , will reduce energy consumption to enhance sustainability and improve the circuit ’ s overall emissions profile .
These will inevitably be contingent on an energy-efficient grinding circuit , which is where the HPGR dry finish grinding concept , in combination with the FTM mill , comes in , being able to lower emissions , operating costs and water requirements .
The company stated : “ The HPGR finish grinding concept with our FTM stirred media mill saves thousands of cubic meters of process water per day compared to conventional grinding circuits .”
Outside of the more ‘ revolutionary ’ approaches FLSmidth is taking to help mining companies achieve their ultimate climate ambitions , it stresses the need to routinely leverage the data feeds coming off its machines to create maintenance plans that achieve a flowsheet ’ s full efficiency potential .
“ Digital solutions are increasingly helping us to provide our customers with sustainable mining solutions ,” the company said .
For example , a large copper mine in the Americas installed FLSmidth ’ s LoadIQ ® mill scanning technology on its SAG mills and , in combination with an APC system , achieved a 10 % increase in throughput and a 9 % reduction in energy consumption per tonne of copper produced , the company said .
FLSmidth concluded : “ We are making good progress on the FLSmidth MissionZero Mine , and our focus on energy-efficient comminution , ecobeneficiation , water and tailings management and digital solutions are all geared towards achieving sustainable productivity and reducing emissions .”
Weir Minerals ’ efforts to create the most energyand resource-efficient mines in the industry have also seen it recently complete its first sale of a pebble crushing plant featuring the Trio TC84 cone crusher
Weir Minerals collaborating on comminution
The latest leg of Weir Minerals ’ Emissions Strategy has seen the company take up the Scope 4 emissions category to outline to customers the emissions avoided using its energy-efficient technologies .
“ The comparative measure between the emissions of one technology versus an alternative has the term Scope 4 – avoided emissions ,” the company explained , saying it has the potential to quantify the sustainability benefit of its products and solutions and , thereby , support customers in delivering their net-zero targets .
Weir Minerals is using a data-driven approach to calculate this , but it already has its first comminution products lined up for Scope 4 calculations .
Bjorn Dierx , Weir Minerals , Global Product Manager – Enduron HPGR , told IM : “ The greatest initial opportunity to bring down Scope 4 avoided emission lies in replacing energy-intensive SAG mills with HPGRs . This is where the biggest gains can be made . We ’ ve seen our Enduron ® HPGRs process the same amount of ore at 30-40 % less energy than these mills .”
It is not only the energy intensity of grinding operations being addressed with the use of Enduron HPGRs , according to Dierx , who references a co-developed flowsheet at Fortescue Metal Group ’ s majority-owned Iron Bridge magnetite mine in Western Australia as an example .
40 International Mining | SEPTEMBER 2023