AMMONIA LEACH-SOLVENT EXTRACTION-ELECTROWINNING PROCESS FOR TREATMENT OF HIGH ALKALINE GANGUE-CONTAINING COPPER ORES

摘要

Tangdan copper mine, which is located in Yunnan Province, China, has a deposit of 1.16 million metric tons of copper. The copper mineral is a high alkaline gangue containing oxide and sulfide copper with CaO and MgO accounting for 40% weight in the ore. The copper concentrate produced from the mixed ore has a relatively low content of 14～16% copper and 3～4% S while CaO and MgO contents are higher than 20%, respectively. The concentrates are not suitable for direct treatment by a smelter, and are therefore used as supplementary concentrates. A process combining roasting, ammonia leaching, solvent extraction and electrowinning has been developed for treatment of the concentrates. The laboratory tests, process development and pilot operation results are discussed in this paper. A pilot plant with a capacity of 500 t copper cathode per annum was built in 1997 and it has been running well since being brought on line. LIX 54-100 is employed to extract copper from ammonia leach liquors. The effects on the extraction and electrowinning, especially the ammonia concentration, are discussed in this paper. The operational measures for the pilot plant are also given. The economical feasibility of this pilot plant is reviewed.