Magnetic Density Separation of Diamonds From Gangue

Abstract

In view of the predicted diamond shortage in 2010, a number of innovative processes have been proposed recovering <2 mm diamonds which are currently lost in tailings. One of these innovations is based on the ferrohydrostatic separation (FHS) as developed by De Beers. This new method, known as magnetic density separation, creates an apparent density range inside a ferromagnetic fluid in order to create multiple density fractions in a single process. Results of lab-scale experiments separating a mixture of orthoclase, calcite, olivine and ilmenite are presented. In this mixture olivine represents the diamond fraction. Orthoclase and calcite simulate the lighter density minerals while ilmenite represents the heavy density fraction.

An Innovative Magnetic Density Separation Process

“…This allows the separation between particles with different densities since they would suspend at different heights. The separation is called MDS and has been studied in the past decades [4][5][6] across a wide range of applications including resource recovery (car metals [7]; incinerator bottom ash [8,9]; WEEE [10]; plastics [11][12][13][14]), mineral processing (coal preparation [15]; diamond and precious metal enrichment [16][17][18]), and seed sorting [19].…”

An Innovative Magnetic Density Separation Process for Sorting Granular Solid Wastes

“…This allows the separation between particles with different densities since they suspend at different heights and allows the separation between multiple particle streams in one single process. The separation is called MDS and has been studied in the past decades [10][11][12] across a wide range of applications including resource recovery (car metals [13]; incinerator bottom ash [14,15]; WEEE [16]; plastics [17,18]), mineral processing (coal preparation [19]; diamond and precious metal enrichment [20][21][22]), and seed sorting [23].…”