Fifty years of development of copper extraction

During the last 50 years, the art and science of extraction of copper has undergone a remarkable technological development. The advent of froth flotation process has made it possible to treat low-grade sulphide ores. Development of new processes both in the field of pyrometallurgy as well as hydrometallurgy has paved the way for economic recoveries of associated minor metals as well as contributed to the control of environmental pollution. Several improvements in operating techniques, such as autogenous grinding, green-feed reverberatory smelting, automatic punching of converters, slag flotation, gas polling for refining, have contributed towards smooth production of copper as well as result in economy of operations. In electro-refining of copper the ASARCO shaft melting furnace and continuous casting of rods fore improved finished product are the order of the day. These technological developments have made available the valuable metal-copper, in ever increasing and larger quantities to the service of mankind. (J.R. Sampath, Hindustan Copper Ltd., Khetrinagar (Rajasthan)