Modernization of Chinalco Toromocho Copper Tailings Thickeners

Abstract

The Chinalco Toromocho copper mine uses four (4) 43-m diameter paste-type tailings thickener, each is designed to process over 1,300 dry metric tons per hour, mtph and 3,600 cubic meters per hour, m3/h of slurry. The target non-Newtonian underflow was designed to be pumped to the tailings storage facility, TSF to be surface stacked. Difficulty has been experienced achieving the target underflow causing water balance, pumping capacity and other issues. Chinalco contracted WesTech to perform an optimization study to evaluate the benefit of retrofitting their feed system and mechanism of their thickeners with the latest advances in the market. Plant trend data was analyzed over the past 1.5 years, establishing the current operation of the site. The tailings stream variation range in dry mtph, particle size distribution, PSD, and flocculant consumption, are shown. The underflow weight percent and overflow clarity operating ranges were tracked. The analysis gives the effect these critical parameters have on thickener performance. A comparison is provided of the predicted modernization performance in response to the established operating variability. This paper provides a review of the Toromocho thickeners trend data based performance, optimization study results, and the mine’s way forward to optimize their tailings thickeners.