Development and use of a Taylor-Vortex column for fine coal beneficiation

A Taylor-Vortex column was designed and constructed at the University of Pittsburgh to explore its potential advantages for solid-solid separations. The Taylor-Vortex column is a simple device that utilizes the principle of Taylor-Vortex flow to achieve an effective multi-stage solid-solid particle separation based on density differences. The Taylor-Vortex column consists of two vertical concentric cylinders mounted on a base. The inner cylinder can be rotated at low speeds (1--28 rpm) using a variable speed motor. As the inner cylinder rotates, stable vortex rings are formed throughout the column. These rings are evenly spaced along the axial direction of the cylinder, and each of these vortex rings may be regarded as a ``barrierless`` mixing stage. When a density gradient is imposed, such a column can be operated as a continuous multi-stage separation device for solid-solid separations, much like a distillation column is used in an oil refinery.