High-grade copper-bearing ores have been increasingly depleted and instead, low-grade and complex ores have now become dominant in copper production. The existing production process for low-grade copper molybdenum ore has the disadvantage of high cost and high energy consumption. Therefore, a great deal of attention is being paid to the simple and environmentally-friendly bioleaching. Without proper heap bioleaching technology, millions of tonnes of low-grade copper ore might be left as waste.
While many studies have been carried out on the bioleaching of chalcopyrite, which is the main copper-bearing material, few studies have been reported on the direct bioleaching of complex minerals containing chalcopyrite.
Cha Kwang Chon, a post-graduate student at the Faculty of Mining Engineering, investigated the feasibility of bioleaching for copper recovery from low-grade, complex chalcopyrite in a column reactor.
The ore mainly contains pyrite and chalcopyrite as sulphide minerals and quartz as the main gangue minerals.
He carried out the tests in a column reactor using a mixture of inoculums used for bioleaching of pyrite.
The results showed that the dissolution of copper reached 85% after 120 days at 35-45℃.