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19.11.2018 Disc magnetic separator for processing coltan

Master Magnets, Redditch, UK – a Bunting Magnetics company – has manufactured and despatched a disc magnetic separator to Nigeria for use in the processing of coltan (a combination of columbite and tantalite).  The separator is used in a process primarily to extract tantalum.  This is a key raw material in the manufacture of batteries.

The disc magnetic separator enables the separation of different minerals with varying levels of magnetic susceptibility.  Concentrated fractions of minerals are collected and then further processed. For this new project, tests were undertaken in the Master Magnets test plant at Redditch.  They confirmed the level of separation, capacity and the magnetic separator configuration.  Afterwards the samples were returned to the customer in Nigeria for analysis.  On receiving confirmation that the separation matched the processing requirements, an order was placed.

Typically, a disc magnetic separator features up to three high-intensity electromagnetic discs, each set at a different height from a feed conveyor.


  • Disc 1: this will be set the furthest from the feed material; the objective is to extract only the most magnetically susceptible particles.
  • Discs 2 and 3: the second and third discs are set at lower gaps; this increases the magnetic force at each disc and enables the separation of different grades of magnetic material.


Magnetic intensity can be further adjusted by varying the current of each coil.  This allows each disc separator to be designed and set up for an individual mineral ore. For this latest project, the test work recommended a model MDS3-375 disc magnetic separator.  This featured three high-intensity electromagnetic discs, (with six electromagnetic coils) each set at a different height from a 380mm wide feed conveyor. The tests had determined that the MDS3-375 could process effectively at a rate of between 500 and 600kg/h.

In the Master Magnets test facility, trials are conducted on mineral materials from deposits all over the world.  From the tests, it is possible to confirm what separation is possible on what equipment. This then forms the basis of a separation guarantee for any equipment order. Technical details of the disc magnetic separator are available on the company’s website. 


Disc magnetic separator in final stages of manufacture

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