TY - CPAPER T1 - Challenges Faced by Dexing Copper Mine ― A Case Study of Dump Leaching in China T2 - Rock Dumps 2008: First International Seminar on the Management of Rock Dumps, Stockpiles and Heap Leach Pads AU - Yin, SH AU - Wu, AX AU - Wang, HJ AU - Zhou, B ED - Fourie, AB A2 - Fourie, AB DA - 2008/03/05 PY - 2008 PB - Australian Centre for Geomechanics PP - Perth CY - Perth C1 - Perth SP - 179 EP - 191 AB - Dexing Copper Deposit, located in Jiangxi province, China, is one of the largest porphyry copper deposits in the world, the copper content of which exceeds eight million tonnes. Fine hundred million tonnes of waste rock with grades between 0.1 and 0.3 will be produced during open pit mining of Dexing. The amount of copper metal is 1.2 million tonnes. In order to extract copper metal from those secondary resources and resolve the environmental problems caused by acidic water and heavy metals released from the waste rock dump, a dump bioleaching-solvent extraction-electrowinning plant was designed based on a series of experimental investigations. Presently, there are a number of challenges faced by this plant, such as low recovery efficiency, low Cu2+ concentration and limited production. The investigation shows that the low- grade of the dump, refractoriness of chalcopyrite, small sprinkling area, leakage of pad, small bacteria population, low dump permeability are the main factors that contribute to the challenges. Several measures were exercised by the plant, such as separating ores from rocks, stripping and loosening the surface layer of dump, loosening the entire dump by use of explosives. Besides those challenges, stability of the high and steep slope of the dump is a hidden danger to which much attention is not paid. The height of the dump exceeds 70 m, and the inclination of the slope is 55°. The failure of dump could result in a dangerous disaster. Mechanical properties of the waste rock before and after leaching were investigated. The result shows that the normal stress, shear strength and cohesion decreased sharply during the leaching process. UR - https://papers.acg.uwa.edu.au/p/802_16_Yin/ ER - DO - 10.36487/ACG_repo/802_16