Computational Simulation of Spiral Concentrator Flows in the Mineral Processing Industry

Spiral separators are gravity concentrating devices that play an important role in the fine coal and mineral processing industries. Particles are separated on the basis of their density and size and, in an attempt to optimise the separation mechanisms, the spiral design has evolved almost exclusively through empirical analysis. To understand the underlying physical processes at a more fundamental level, the past decade has seen developments in theoretical considerations of spiral performance. The present paper is a continuation of this approach, and uses computational fluid dynamics (CFD) to examine the fluid flow behaviour of the LD9 spiral unit used for fine coal processing. Results are obtained using a commercially available CFD code, FLUENT, and are validated against an ongoing collaborative experimental research program. It is envisaged that the model will provide the basic framework for an ultimate parametric assessment of the spiral design.