Business Scope

Metallurgical industry

Release Time:

2023-05-27 16:37

Metallurgy refers to the process and technology of extracting metals or metal compounds from minerals and using various processing methods to make metals into metal materials with certain properties.
Metallurgy has a long history of development, from the Stone Age to the subsequent Bronze Age, and then to the large-scale development of modern steel smelting. The history of human development is integrated with the history of metallurgical development.
The main technologies of metallurgy include pyrometallurgy, hydrometallurgy, and electrometallurgy. With the successful application of physical chemistry in metallurgy, metallurgy has moved from technology to science, and thus there is a metallurgical engineering major in universities.

Pyrometallurgy
Pyrometallurgy is a metallurgical process carried out at high temperatures. Part or all of the minerals in the ore or concentrate undergo a series of physical and chemical changes at high temperatures to generate another form of compound or element, which are respectively enriched in gaseous, liquid, or solid products to achieve the purpose of separating the metal to be extracted from the gangue and other impurities. The heat energy required to realize the pyrometallurgical process is usually supplied by fuel combustion, and some are supplied by chemical reactions in the process. For example, the oxidation roasting and smelting of sulfide ore do not require fuel heating; the metal thermal reduction process is also self-heating. Pyrometallurgy includes: drying, calcination, roasting, smelting, refining, distillation and other processes.

Hydrometallurgy

Hydrometallurgy is a metallurgical process carried out in solution. Hydrometallurgy does not have high temperatures, generally below 100°C. The temperature of high-temperature and high-pressure processes in modern hydrometallurgy is only about 200°C, and in very few cases, the temperature can reach 300°C. Hydrometallurgy includes: leaching, purification, metal preparation and other processes.

1. Leaching uses an appropriate solvent to treat the ore or concentrate, so that the metal to be extracted enters the solution in the form of a certain ion (cation or complex anion), while the gangue and other impurities do not dissolve. This process is called leaching. After leaching, clarification and filtration, a leachate containing metal (ions) and an insoluble residue (leaching residue) made of gangue minerals are obtained. For some ores or concentrates that are difficult to leach, pre-treatment is often required before leaching to convert the metal to be extracted into a certain compound or salt that is easy to leach. For example, sulfation roasting to convert to soluble sulfate, etc.

are commonly used pre-treatment methods.

1. Purification In the leaching process, some metal or non-metal impurities often enter the solution together with the metal to be extracted. The process of removing these impurities from the solution is called purification.

2. Metal preparation The process of extracting metal from the purified solution by displacement, reduction, electrodeposition and other methods.

Electrometallurgy
Electrometallurgy is a method of extracting metals using electrical energy. According to the different effects of using electrical energy, electrometallurgy is divided into electrothermal metallurgy and electrochemical metallurgy.

Metallurgy

1. Electrothermal metallurgy is a method of smelting using electrical energy converted into thermal energy. In the process of electrothermal metallurgy, in terms of the essence of its physical and chemical changes, there is little difference from the pyrometallurgical process. The main difference between the two is the different sources of heat energy during smelting.

2. Electrochemical metallurgy (electrolysis and electrodeposition) uses electrochemical reactions to precipitate metals from solutions or melts containing metal salts. The former is called solution electrolysis, such as the electrolytic refining of actinium and the electrodeposition of zinc, which can be classified as hydrometallurgy; the latter is called molten salt electrolysis, which not only uses the chemical effect of electrical energy, but also uses electrical energy to convert into thermal energy to heat metal salts to make them into a melt, so it can also be classified as pyrometallurgy. The production process of extracting metals from ore or concentrate often has both pyrometallurgical and hydrometallurgical processes. Even the pyrometallurgical process, for example, the pyrometallurgical smelting of sulfide pot concentrate, still requires a hydrometallurgical electrolytic refining process at the end; and in hydrometallurgical zinc smelting, zinc sulfide concentrate also needs to be pre-treated with high-temperature oxidation roasting.