Recovery of Ultra-Fine Tungsten and Tin from Slimes Using Large-Scale SLon-2400 Centrifugal Separator

Abstract

China is very rich in tungsten and tin resources, but most of them are finely disseminated with gangues, and thus, fine grinding is required for effective separation, which results in the abundant production of ultra-fine tungsten and tin values into slimes and tailings. The SLon centrifugal separator is highly effective in recovering ultra-fine heavy particles, because it operates on the centrifugal acceleration of particles in the flowing film of a few millimeters thick. The recovery of ultra-fine tungsten minerals from a slime assaying 0.22% WO3, in which 81.85% distributed in −40 µm fraction, was investigated using large-scale SLon-2400 centrifugal separator. Under optimized operating conditions, it produced a primary tungsten concentrate assaying 1.65% WO3 at a high recovery of 77.83%. Moreover, it produced a primary tin concentrate assaying 1.56% Sn at a high recovery of 79.85% from a tin slime assaying 0.27% Sn, in which 74.78% Sn was distributed in −40 µm fraction; then, followed by the flotation cleaning process, a final tin concentrate assaying 16.23% Sn with 66.7% recovery was produced. It was particularly noted that in this large-scale centrifugal separator, the three-conical separation drum stuck with abrasion-resistant ceramic slices on its inner surface played a key role for achieving high constant separation performance. It was concluded that the SLon centrifugal separator has important application prospects for high-efficient recovery of ultra-fine heavy minerals from slimes and tailings.