Application of the grade-recovery curve in the batch flotation of Polish copper ore ☆

Ores and raw materials are subjected to mineral processing operations to increase the content of their useful components. Upgrading of these materials can proceed with different selectivity and therefore, there is a need to know and monitor the separation results of the process. The separation results can be evaluated using upgrading tables and curves. The shape of lines of the upgrading curves are usually complex and depends on the graph type and process parameters. The grade-recovery curves are frequently used because are practical and indicate several characteristic features of separation results. Separations by means of batch flotation of several different shale, dolomite and sandstone Polish copper ores were performed along with determination of their mineral composition, copper content, liberation degree, and maximum theoretical copper content in the first concentrate. These data, plotted as the grade-recovery curves, allowed finding other characteristic points such as practical maximum copper content in the first concentrate, maximum curvature which, to a great extent coexists with the liberation degree, maximum recovery of ore valuable components, and the slope of the grade-recovery curve at high recoveries as a measure of liberation of middlings. Correlations between theoretical and practical maximum copper contents in the first concentrate, which depend on the ore type, were also presented. It was confirmed that the ore type significantly influences the shape of the grade-recovery curve and its characteristic points.