The NoBLOCK Technology A Major Breakthrough in Wet High Intensity Magnetic Separation (WHIMS)

Abstract

Since its introduction in 1963 by G.H. "Jones", WHIMS MS has proven to be, worldwide, a major technology for separating several types of ore fines from their contaminants. Unfortunately, despite its superb characteristics, even if the best operational procedures are followed, one main issue lasts. It is the blocking of the matrix gaps by oversized particles. Protection screens have been employed to wipe out this blockage, though only partially effective. Creative methods and tools have been developed to facilitate and speed up the cleaning process. But, in fact, along 50 years, the matrix blockage nightmare lingered defying the minds involved with Whims operation. The recent environment demands and the need to reduce costs by recovering ore ultra-fines currently being disposed in tailing ponds, further posed a new challenge. Reportedly these ore ultra-fines, typically below 75 microns, demand smaller gaps for its recovery than today's bottom limit 1.5 mm. The blockage issue worsens even more and to solve it, Gaustec Magnetism, after two years of research and test work, finally succeeded in developing The Brand New NoBLOCK® Technology presented here.

Recovery of pellet feed from tailings dams

“…The recovery of ore fines from tailings dams usually poses a number of challenges, such as material heterogeneity, throughput fluctuations due to difficulty in recovering and handling the tailings, and the presence of contaminants such as natural sediment, sand, and organic materials. Ribeiro and Ribeiro (2015) show the problems in magnetic concentration due to blockage in the matrix by coarse particles and organic materials.…”

Magnetic concentration route for recovering pellet feed fines stored in a mining dam

“…Concerning relevant studies dealing with the reprocessing of iron ore disposed in dams in Brazil in the last decade, Gomes et al (2011) characterizated fines stocked in a pond and proposed a concentration route consisting of magnetic separation, desliming and flotation, and a secound route consisting of magnetic separation, which reached the best performance, aiming for a concentrate adequate for use in the metallurgical industry. According to Ribeiro & Ribeiro (2013) and Ribeiro & Ribeiro (2015), since the introduction, in 1963, of the Wet High Inten-sity Magnetic separator (WHIMS), the technology has proven to be efficient for separating several types of iron ore from their contaminants. WHIMS process variables, such as solid feed percentage, distance between grooved plate tips (GAP), magnetic field intensity and wash water pressure can be easily adapted to various ore types.…”