Copper Recovery from Silicate-Containing Low-Grade Copper Ore Using Flotation Followed by High-Pressure Oxidative Leaching

Abstract

In this paper, we present the results for recovery of copper from silicate-containing low-grade copper ore using flotation followed by atmospheric and high-pressure oxidative leaching. The effects of various flotation parameters, such as flotation time, PAX dosage, slurry pH and air injection rate on beneficiation of copper from the low-grade copper ore were studied. The recovery of copper reached 93.1% and the grade of copper improved to 18.2 mass% from 0.4 mass% under collector-less optimum flotation conditions. The enrichment ratio of copper in the concentrate was 45. The copper concentrate obtained from flotation of the low-grade copper ore was treated by atmospheric leaching and high-pressure oxidative leaching processes. A maximum recovery (>93.0%) of copper was obtained by high-pressure oxidative leaching in the water, whereas the copper recovery was lower than 12% in the sulfuric acid solution under atmospheric leaching conditions. The copper concentration in a pregnant leach solution enriched up to 15.0 g/L under the optimized leaching conditions. The effect of impurity such as iron in the sample on the froth flotation and both leaching processes is also considered. A process flow for the recovery of copper from silicate-containing low-grade copper ores is proposed as a result of these studies.