SEPARATION & CLASSIFICATION
greenfield application the indicative energy requirements for the grinding circuit can be up to 50 % lower than current designs .
Dry mag sep to reduce water usage
Dry magnetic separation offers a viable option when mineral processing plants face reduced water consumption challenges . IM spoke to Jose Marin – Eriez Director of Minerals and Materials Processing . He commented : “ Dry magnetic concentration and separation are as important as any wet process in mining and concentration of metallic as well as non-metallic mining . There are certain challenges with dry processes that currently may steer mineral process engineers in the direction of wet processes because of established traditional processes . Significant advantages of wet mineral processing are grinding , milling and concentration . The available technology for the ‘ perfect grind ’ as well as separation technologies are well known and readily available commercially . Concentration in wet environment takes advantage of particle dispersion and the ease of moving material through piping . Elevating and storing slurries in holding tanks are straight forward .”
However , Marin argues that dry milling and concentration may not necessarily be getting the consideration it deserves . “ A good example is dry iron ore concentration , and more specifically magnetite . Magnetic separation is the least costly technology to concentrate magnetite . Once liberation of the ore is achieved , wet magnetic concentration will easily produce a saleable product for steel making , heavy media circuits and other uses . Typical mineral process engineers automatically think of a wet process because it is proven technology . Unfortunately , not all iron ore deposits are conveniently located in areas where water is abundant or there may be severe water restrictions . The alternative is dry concentration . Today , there is available technology that mirrors a wet process . The overall performance of dry concentration does not equal the same performance of a wet process . Perhaps , this is the case because reverse flotation is utilised at the final stage in a magnetite process to effectively reduce SiO 2 and other nonmagnetic minerals . It should be noted that not all plants use reverse flotation because of their inability to obtain required permits from nearby localities .”
Given these facts about magnetite
Dry iron ore concentrator with vibratory feeder
concentration , Marin says some interesting developments have taken place to improve the overall performance of dry concentration ( magnetite mass yield and grade ie higher total Fe . “ Overall recovery of magnetite in a dry process starts in the early cobbing and rougher stages of the process . Traditional dry cobbing / rougher pulleys or drums were limited by the magnetic field generated by either separator with a surface strength between 1,000 to 2,000 gauss . The development of a wide range of magnetic elements constructed with rare earth magnets and hybrid elements targeting 3,500 gauss on the surface of the separator , defined as MIMS ( Medium Intensity Magnetic Separators )
A gold CIL / CIP one stop shop
At the recent 2023 SME Annual Conference & Expo in Denver , Colorado , Derrick Corporation announced a strategic alliance with Groupe Industries Fournier and Sepro Mixing & Pumping , of which more details have now emerged . Derrick told IM that the partnership was assembled to help optimise new and existing customer operations , providing a one-stop solution for gold CIL / CIP processing plants worldwide .
Derrick says customers will gain access to an exclusive suite of products and services , including engineering design , tanks , mixing and pumping equipment , and urethane interstage screens . Derrick offers its clients leading-edge solutions and around-the-clock , award-winning service to maximise separation efficiency .
Derrick ’ s products are renowned for their rugged reliability in industries known for intensely challenging environments and ever-evolving demands . Its gold processing solutions for CIL / CIP circuits include trash screens , G-Vault urethane interstage screens , carbon sizing screens , dewatering screens , tails safety screens , and other processing stages . Its latest innovation is its Trilogy™ advanced screening system for increased gold recovery . Trilogy is composed of individual thermoplastic components that may be assembled into various configurations for added flexibility .
Sepro is Canada ’ s largest supplier of mineral processing and aggregate equipment . The core of Sepro ’ s industrial mixing and pumping knowledge comes from years of troubleshooting and problem-solving . Sepro personnel have travelled the world identifying and solving some of the world ’ s most complicated mixing problems with its agitator impellers , including in cyanide leaching circuits .
For its part , Fournier Industries Group has a specialised team that operates in water treatment , mining , aluminum smelters , hydroelectric rehabilitation , and in heavy industrial markets . “ They are recognised for excellence in integrated design , manufacturing , installation , and maintenance services for their mechanical equipment .”
16 International Mining | MAY 2023