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Extractive metallurgy is a branch of metallurgical engineering wherein process and methods of extraction of metals from their natural mineral deposits are studied. The field is a materials science, covering all aspects of the types of ore, washing, concentration, separation, chemical processes and extraction of pure metal and their alloying to suit various applications, sometimes for direct ...
A good example of the autoclave leach process can also be found in the metallurgy of zinc. It is best described by the following chemical reaction: [citation needed] 2 ZnS + O 2 + 2 H 2 SO 4 → 2 ZnSO 4 + 2 H 2 O + 2 S. This reaction proceeds at temperatures above the boiling point of water, thus creating a vapour pressure inside the vessel.
Similar to the Anglo-Saxon method for cupellation, the Chinese employed the use of a base metal to extract the target metal from its impurities. First, the base metal, iron, is hammered into thin sheets. The sheets are then placed into a trough filled with “vitriol water” i.e., copper mining water which is then left to steep for several day.
The main types of metal recovery processes are electrolysis, gaseous reduction, and precipitation. For example, a major target of hydrometallurgy is copper, which is conveniently obtained by electrolysis. Cu 2+ ions are reduced to Cu metal at low potentials, leaving behind contaminating metal ions such as Fe 2+ and Zn 2+.
Smelting involves more than just melting the metal out of its ore. Most ores are the chemical compound of the metal and other elements, such as oxygen (as an oxide), sulfur (as a sulfide), or carbon and oxygen together (as a carbonate). To extract the metal, workers must make these compounds undergo a chemical reaction.
Bioleaching is the extraction or liberation of metals from their ores through the use of living organisms.Bioleaching is one of several applications within biohydrometallurgy and several methods are used to treat ores or concentrates containing copper, zinc, lead, arsenic, antimony, nickel, molybdenum, gold, silver, and cobalt.
Volatilizing roasting, involves oxidation at elevated temperatures of the ores, to eliminate impurity elements in the form of their volatile oxides. Examples of such volatile oxides include As 2 O 3, Sb 2 O 3, ZnO and sulfur oxides. Careful control of the oxygen content in the roaster is necessary, as excessive oxidation can form non-volatile ...
An electrolytic cell is made of a steel shell with a series of insulating linings of refractory materials. The cell consists of a brick-lined outer steel shell as a container and support. Inside the shell, cathode blocks are cemented together by ramming paste. The top lining is in contact with the molten metal and acts as the cathode.