COMMINUTION AND CRUSHING
A catalyst for change
Optimising crushing power requirements , using dry or energy-efficient comminution methods , evaluating novel screening technology … all this and more are included in the industry ’ s blueprint for ‘ net zero ’ processing flowsheets , Dan Gleeson reports
As has been well documented , the comminution sector is a large contributor to mining ’ s greenhouse gas emissions , with grinding to produce minerals and metals consuming roughly 3 % of the world ’ s electrical energy .
This means crushing and grinding are key focus areas for mining companies looking at reducing their energy consumption in line with ambitious ‘ net zero ’ targets to 2030 , 2035 , 2040 and beyond .
With such an end goal in mind , miners are going back to several ‘ alternative ’ crushing and grinding technologies previously dismissed when throughput and operating costs were the main operating considerations .
Now , when evaluating their future mineral process flowsheets in the face of sustainability goals , all options are back on the table .
Sustainable flowsheet gains
“ A lot of time we work it backwards ; we look at the final product required as that will determine the upstream flowsheet and what equipment you can and cannot use ,” Joe Dziedzina , Global Product Manager – HPGR at FLSmidth , says .
This philosophy has resulted in the development of hundreds of fit-for-purpose mining flowsheets , many of which are now becoming more energy- and water-efficient .
FLSmidth is engineering this move through its
MissionZero sustainability program , which looks to reduce emissions in cement and mining to zero by 2030 . By this date , the company plans to deliver solutions that make it possible to operate zero-emissions cement plants and manage zeroemissions mining processes . Achieving these goals , FLSmidth says , will require a paradigm shift in collaboration , innovation and adoption of new technology in the industries .
This shift has , arguably , already seen the introduction of the REFLUX Flotation Cell™ , which reduces plant footprint as well as water , air and energy requirements throughout the process flowsheet , according to the mining OEM .
The RFC™ , FLSmidth says , reduces capital expenditure by 35 %, with results from pilot-scale studies indicating that it can help mines use up to 60 % less energy in their flotation circuits . Improved kinetic efficiency also reduces the amount of water used in the recovery process , FLSmidth claims .
Eldorado Gold recently installed a 2.4 m diameter by 2.2 m long Weir Minerals Enduron HPGR at the Kışladağ operation in Turkey
In this regard , it ticks off the two main sustainability boxes – reduced energy and water use .
Development of the RFC came from the extension of an already-established partnership with the University of Newcastle . This partnership also saw the successful development and commercialisation of the REFLUX Classifier ( RC™ ).
Another area to look at that could influence future sustainable mineral processing routes is , in fact , the cement industry .
Cement may only represent a third of FLSmidth annual revenues , but it continues to act as a fertile proving ground for developing sustainable mining solutions , according to Wayne Douglas , Head of R & D , Innovation and the Minerals Testing and Research Center / Lab ( MTCR ), at FLSmidth .
“ The cement industry is a key driver for our own mining innovations ,” he said during a recent tour of the MTCR in Salt Lake City , USA . “ Companies in the cement sector are not able to leverage high-grade orebodies that differentiate their assets from their peers . This means they are all about productivity and efficiency .”
Just last year , FLSmidth introduced a calcined clay solution to enable a reduction of CO 2 emissions from cement production of up to 40 %, as part of its MissionZero ambition .
24 International Mining | APRIL 2022