Dense Medium Cyclone Separation of Fine Particles Part 2. The Effect of Medium Composition on Dense Medium Cyclone Performance

Abstract

The effect of medium composition on dense medium cyclone performance is investigated. It is found that a change in composition affects medium stability and rheology, and may lead to different responses in separation efficiency and cutpoint shift. The final result depends on whether the medium stability or rheology is the dominant factor, and also on the feed particle size.

An ideal medium composition is found to be one with a bimodal panicle size distribution. Such a medium exhibits low viscosity and improved stability. Optimum dense medium cyclone performance is achieved with the magnetite dense medium characterized by a bimodal panicle size distribution when the medium contains approximately 25% fine and 75% coarse magnetite. With a bimodal dense medium, separation efficiency is more closely related to medium rheology, while the cutpoint shift is more closely dependent on medium stability.

Keywords:

• Gravity separation
• dense medium
• dense medium rheology. dense medium stability
• magnetite dense medium
• dense medium cyclone
• separation efficiency
• rheology
• Casson viscosity
• Casson yield stress
• particle size distribution
• bimodal size distribution