A modified release analysis procedure using advanced froth flotation mechanisms. Technical report, September 1--November 30, 1995

Abstract

The objective of this study is to reinvestigate the release analysis procedure, which is traditionally conducted using a laboratory Denver cell, and to develop a modified process that can be used for all froth flotation technologies. Recent studies have found that the separation performance achieved by multiple stage cleaning and, in some cases, single stage cleaning using column flotation is superior to the performance achieved by the traditional release procedure. These findings are a result of the advanced flotation mechanisms provided by column flotation, which will be incorporated into a modified release analysis procedure developed in this study. A fundamental model of an open column has been developed which incorporates the effects of system hydrodynamics, froth drop-back, selective and non-selective detachment, operating parameters, feed solids content, and feed component flotation kinetics. Simulation results obtained during this reporting period indicate that the ultimate separation that can be achieved by a column flotation process can only be obtained in a single cleaning stage if the detachment mechanism in the froth phase is highly selective, which does not appear to occur in practice based on experimental results. Two to three cleaning stages were found to be required to obtain the ultimate performance if non-selective detachment or kinetic limiting conditions are assumed. this simulated finding agrees well with the experimental results obtained from the multiple stage cleaning of an Illinois No. 5 seam coal using the Packed-Column. Simulated results also indicate that the separation performance achieved by column flotation improves with increasing feed solids content after carrying-capacity limiting conditions are realized. These findings will be utilized in the next reporting period to modify the traditional release analysis procedure.