For concentration of weak magnetic ore and ore concentrates it is reasonable to use multi-stage concentration with the following stages:

Extraction of strong-magnetic inclusions and removal of occasional tramp metals. In the cause of separation the product is divided into two parts: strong-magnetic and non-magnetic + weak-magnetic. Non-magnetic + weak-magnetic material is separated once more, usually with magnetic pulleys (SMB model) or modular magnetic drums (SMBM model).

Extraction of weak-magnetic components is performed by a high-power magnetic roll separator (SMVI model). Material fineness can vary from 0,1 up to 10 mm. This allows to significantly widen the sphere of application of such separators by using them for concentration of weak-magnetic ore and concentrates (see Fig.1 - Magnetic separation of tempered haematite-magnetite concentrate, fineness 92,1%, class: -0,6 +0,074 mm, using magnetic separators, produced by «Erga» LLC). Thanks to magnetic concentration, useful content of the concentrate reaches 95% or more, and content of useful material in the waste product is reduced significantly. Usual ratio of useful product, transferred to the concentrate, can reach up to 75% of its original quantity, or even up to 95% for strong-magnetic materials.

Fig. 1. Magnetic separation of tempered haematite-magnetite concentrate, fineness 92,1%, class: -0,6 +0,074 mm, using magnetic separators, produced by «Erga» LLC