Alternative Materials for Dense Medium Separations

摘要

In response to concerns regarding cost and future supply of magnetite, a study has been performed to evaluate the potential of alternative materials that can be used to generate a dense medium for coal-cleaning applications. Alternative materials included waste steel slag, fine sand, and high-density material existing in run-of-mine feed. Under certain conditions, each of the materials tested provided separation efficiencies that meet industrial standards including probable error values of around 0.03. Dense medium derived from the non-magnetite sources achieved organic efficiency values exceeding the 95% level over a medium density range from 1.3 RD to 1.6 RD with lower than normal density offsets. Lower cost, coarse magnetite provided excellent separation efficiencies when medium density values above 1.6 RD are sufficient to meet product grade requirements.