ORE SORTING clients ,” Rados says .
The MMD actuation system , premised on the MMD high speed , multi-product diverter , can separate the ore stream into multiple products , enabling production of high-grade , low-grade and near-grade material to facilitate integrated sorting options .
The MMD Rados bulk sorter has the ability to process a wide PSD range of feed ore and different ore types , requiring only an algorithm change that can be conducted remotely and instantaneously . In addition , the automated analyser calibration process can be carried out without stopping production .
Chris Pearson , Business Development Director for MMD , said : “ The MMD Rados bulk sorting system not only complements our materials handling portfolio and green mining solutions ethos , but will also offer new and existing clients a streamlined process that cuts waste and improves mining sustainability and productivity .”
In particle sorting , the Stark Rados collaboration focuses on the provision of XRF + particle sorting solutions where the particular sorting application is unique to the functionality of the Rados XRF + particle sorter , Rados says .
“ The complementary Stark project management and integration offering enables the provision of these unique particle sorting solutions in a turnkey project package , including feed material preparation , thereby mitigating the client project execution risk profile ,” Rados explains .
The Rados XRF + particle sorter , Rados says , provides an accurate and consistent particle-byparticle sort , due to : n The unique manner in which the Rados XRF + analyser conducts direct primary analysis of metals or markers ; n Low detection limits ( eg Ca to Fe more than 1,000 parts per million ( ppm ), Co to Sn more than 100 ppm , and Sb to U more than 80 ppm ); and n A mechanical actuation system that facilitates the particle-by-particle sort for a wide PSD range ( 20-150 mm ). Geoffrey Madderson , CEO of Stark Resources , says the Rados XRF + sorting applications the collaboration will initially focus on include : n Separation of Mn and Fe , with Mn / Fe ratio control , at a coarse particle size up to 150 mm . This offering cannot be achieved by other technologies at a coarse size , due to the limited heterogeneity in the sensor responses , according to Madderson ; n Separation of precious metals ( PGMs , Au , Ag ) which have low-grade metal proxies ( ie Cu , Pb , As , Zr and Sb grades that are less than 500 ppm ); n Separation of different rock types where the proxy metals exist but are too low grade to
provide significant density or NIR variation ( eg separation of spodumene from hiddenite and kunzite , and separation of copper oxides and sulphides ); n Specific targeting of copper and cobalt ( Central Africa ), and copper and molybdenum ( South America ) to maximise upgrade and recovery ; n Polymetallic ores such as silver , copper , lead and zinc found in Mexico , South America , Canada , Australia , Europe and the Middle East , for rejection of low-grade base metals and high-density waste , along with barren waste ; n Sorting of rare earth elements ( La , Ce and Nd ) with low detection limits of more than 100 ppm , for rejection of barren waste and ore that is below the cut-off grade for the concentrator ; n Client requirement for a high upgrade scenario to facilitate delivery of a product for offtake without the need for further downstream beneficiation . Copper and lead / zinc ores are particularly amenable to this approach , according to Madderson ; and n Exploitation of uneconomic stockpiles containing near-grade material , and bulk ore sorting discard dumps which contain significant grade variation on a particle scale . The Rados integrated sorting solution combines the MMD Rados bulk sorting solution and the Stark Rados particle sorting solution to facilitate optimisation of throughput , upgrade and recoveries , as well as the best value proposition for clients , Rados says .
“ Use of the same XRF + sorting technology for the bulk and particle sorting solutions enables seamless integration of the two solutions , leveraging the high throughput capacity of bulk sorting ( rougher sort ) with the superior accuracy and recovery of particle sorting ( scavenger or cleaner sort ), significantly reducing the cost per tonne of ore processed , while delivering improved overall efficiencies ,” it concluded .
Magnetic minerals separated on a laboratoryscale WHIMS
Consulting on WHIMS
Preconcentration or ore sorting via magnetic separation means has been part and parcel of the mining industry for decades , with Bunting being one provider of Wet High Intensity Magnetic Separators ( WHIMS ) to the mining sector
A leading global consultancy for mining and mineral processing recently acquired a laboratory-scale WHIMS from Bunting , looking to apply it in its material test facility located in Cornwall , United Kingdom .
The laboratory-scale WHIMS is part of Bunting ’ s range of small-scale high-intensity magnetic separators .
Bunting , which has two manufacturing facilities in the UK , is a leading designer and manufacturer of industrial and high-intensity magnetic separators , electrostatic separators and metal detectors for the mining and mineral processing industry .
“ Controlled material tests on laboratory-scale high-intensity magnetic separators provide vital data on the mineralogy of an ore or deposit ,” the company explained . “ The electromagnetic laboratory-scale WHIMS removes fine magnetics and para-magnetics from mineral slurries . Handling minerals in a slurry or suspension is preferable for many processors , especially when beneficiation involves wet processing .
“ Additionally , a wet process often produces a better separation for very fine materials .”
The laboratory-scale WHIMS features two electromagnetic copper coils mounted either side of a canister housing a matrix , which captures magnetically susceptible particles .
The electromagnetic coils project a manually controlled magnetic field of between 0-20,000 gauss into the open gap of the canister housing the matrix . The level of magnetic field strength in the open gap is set in accordance with the
MARCH 2023 | International Mining 49