Prediction of the Performance of Regrind / Flotation Circuits using Laboratory tests and Quantitative Mineralogical Information

Abstract

Three different regrind circuits were studied to assess whether it possible to predict the performance of the regrind circuits and the subsequent enrichment process. Process audits were conducted on one iron ore regrind circuit and two base metal regrind circuits to determine the performance of the regrind mills, classification equipment and either magnetic separation or froth flotation enrichment. Both laboratory grinding and enrichment tests were conducted to assess the suitability of currently available tests to predict the performance of the associated regrind circuit and enrichment. Simulated particle breakage of the regrind feed particles was also assessed using automated mineralogy and tessellation of the particles. The simulated mill product was then manipulated to simulate a downstream classification and enrichment process. The laboratory methods and simulation showed good correlation with both the regrinding and enrichment phases for the iron ore regrind circuit. It was concluded that either method was suitable for iron ore regrind circuit design or optimization. Due to the complexity of the base metal mineralogy and the flotation process after the regrind circuits it was more difficult to predict the performance of the base metal regrind circuits. The laboratory regrind tests showed good correlation for one circuit. The simulated breakage data provided a poor correlation for the product size distribution compared to the audit data, resulting in poor correlation of the liberation data. It was concluded that the simulated breakage, at very fine grind sizes required a modified method.