Gas Dispersion Measurements in Coal Flotation Cells

Abstract

Coal flotation across the world has undergone major changes over the past thirty years. In a number of new coal flotation plants, the traditional mechanical flota-tion cells have been replaced by pneumatic flotation cells, such as the Jameson Cell and Microcel column cells. Significant steps have also been taken in the under-standing of what happens "beneath the froth". New per-formance evaluation technology has been developed as part of the Australian Mineral Industries Research Association (AMIRA) P9 project. This involves the measurement of gas dispersion characteristics, such as gas, hold-up, super-ficial gas velocity and bubble size in industrial flota-tion cells. A good understanding of these characteristics leads to improvements in coal recovery and reduction in ash content to the final product. This paper describes the variation of gas dispersion chara-cteristics between different flotation machines and looks at a number of case studies within the Australian coal industry. The studies have allowed plant personnel at each coal operation to identify optimum operating conditions for their flotation cells as well as provide information on future plant capacity increases.