COMMINUTION AND CRUSHING
wear rates but also allow the use of improved wear materials and , thus , maximise wear life and reduce wear cost further , he added .
Meanwhile , a newly developed skew limiter is designed to ensure maximum griding efficiency and provide full mechanical protection against excessive skewing , according to Remmers .
In-pit crushing and conveying ( IPCC ) should also come into the reckoning when considering the emissions of the overall mining process , according to thyssenkrupp ’ s Goeing .
“ The initial idea of thyssenkrupp ’ s semimobile crushing plants is to be relocated and , therefore , to follow the mining progress ,” he said . This reduces truck transport distances and
Apart from improving water and energy consumption on mines , HPGRs , in the comminution circuit , bring an inherent reduction in consumables as they operate without the liners , balls , rods and lifter bars that wear so rapidly in traditional milling , according to Weir Minerals Netherlands ’ Stuart Haydon
HPGRs , said the company took a similar integrated approach to solving the mining industry ’ s needs .
“ To ensure that we provide optimal solutions for our customers , we also supply our HPGRs alongside other products to form an integrated sub-circuit ,” he said . “ In some applications – such as a recent magnetite project in Australia – we were able to piggy-back our HPGR with air classification . This dry grinding configuration will bring a huge reduction in water and energy consumption for the customer , while still delivering the required production throughput and the flexibility to deal with different ore characteristics throughout the life of mine .”
Apart from improving water and energy consumption on mines , HPGRs , in the comminution circuit , bring an inherent reduction in consumables as they operate without the liners , balls , rods and lifter bars that wear so rapidly in traditional milling , according to Haydon .
“ Our HPGR ’ s tungsten carbide studs on its rolls , and the protective autogenous layer of crushed material between the studs , provide outstanding protection , resulting in longer life and a reduction in maintenance stoppages ,” he said .
“ Our goal , then , is to continue designing circuits that play to the strengths of HPGRs , while still ensuring that our customers achieve the throughput and productivity they require .”
Instead of looking for a silver bullet in the form of a brand-new piece of revolutionary equipment , miners , at least in the near term , would be better off adjusting existing equipment to the needs of enhanced evolutionary process flowsheets , as well as the continuous improvement of design and maintenance and operating practices , according to thyssenkrupp ’ s Remmers .
He pointed to an improvement in roller longevity for the company ’ s HPGRs as one such development , with a life of 10,000-20,000 hours now regularly achieved in most hard-rock installations .
Use of rotating side plates is another incremental improvement that can offer 20 % higher equipment capacity at nearly the same capital outlay , plus a 15 % reduction in energy consumption and wear costs , according to Remmers . These plates , which can be retrofitted to existing thyssenkrupp HPGRs , not only reduce operating costs , leading also to savings in CO 2 emissions , “ fulfilling the requirements of the miners in regard to their sustainability and environmental goals ”.
FLSmidth , also a strong proponent of IPCC technology , sees increasing energy efficiency and dry milling as key sustainability focus areas to achieve both the industry ’ s and its own sustainability goals , according to Malone and Hoerschkes .
Its HPGR can be used as a dry comminution tool capable of grinding to a very fine product size when used with the types of dynamic classifiers Weir Minerals ’ Haydon mentioned .
Much of these industry projections are reliant on new , powerful digital tools that can simulate outcomes ahead of time , with digital twins , modelling platforms and the like turning many of these conceptual flowsheets into reality , according to Malone and Hoerschkes .
“ Digitalisation is absolutely key to achieving more efficient comminution – when miners are using less power , using less water and so forth , they are having a very direct impact on reducing their costs , helping the bottom line – and the industry ’ s environmental goals ,” they said .
Use of rotating side plates on thyssenkrupp ’ s HPGRs can offer 20 % higher equipment capacity at nearly the same capital outlay , plus a 15 % reduction in energy consumption and wear costs , thyssenkrupp ’ s Juergen Remmers says
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APRIL 2021 | International Mining