Millions of tonnes of low-grade ore and copper-rich tailings await the development of an efficient and economic bioleach process for chalcopyrite (CuFeS 2).The bioleaching of chalcopyrite in situ and in dumps is a practical option only because the low and slow recoveries are countered by the low processing costs (Schnell, 1997).
The Aripuanã Zinc Joint Venture Project is one of the world's tenth largest undeveloped zinc projects and covers a complete mineralized massive sulphide district, with five areas of mineralization (Arex, Ambrex, Babacu, Massaranduba and Mocoto) over a 25 kilometer strike length.
Within the flotation process the pulp phase chemistry has a strong effect on the froth phase and therefore the manipulation of pulp chemistry factors such as the pulp potential (Eh), pH, dissolved oxygen (DO) and ionic strength (IS) can improve flotation performance.
Froth flotation is considered to be the most widely used method for ore beneficiation. In ore beneficiation, flotation is a process in which valuable minerals are separated from worthless material or other valuable minerals by inducing them to gather in and on the surface of a froth layer.
The process of extracting copper from copper ore varies according to the type of ore and the desired purity of the final product. Each process consists of several steps in which unwanted materials are physically or chemically removed, and the concentration of copper is progressively increased.
Copper mining in the United States has been a major industry since the rise of the northern Michigan copper district in the 1840s. In 2017 the United States produced 1.27 million metric tonnes of copper, worth $8 billion, making it the world's fourth largest copper producer, after Chile, China, and Peru.