Main metallurgical technology

2018-07-11

Fire metallurgy

Pyro metallurgy is a metallurgical process under high temperature. A series of physical and chemical changes in the minerals or minerals in the ore or concentrate, formed by a series of physical and chemical changes, to produce another form of compound or substance, enriched in gas, liquid or solid products, to achieve the purpose of separating the metal from the gangue and other impurities. The heat energy needed to realize the process of fire metallurgy is usually supplied by fuel combustion and by chemical reaction in the process. For example, the oxidation roasting and smelting of sulfide ores do not need to be heated by fuel; the process of metal thermal reduction is also self heated. Pyro metallurgy includes drying, roasting, roasting, smelting, refining, distillation and so on.

Hydrometallurgy

Hydrometallurgy is a metallurgical process in solution. The temperature of hydrometallurgy is not high, generally lower than that. The high temperature and high pressure process in modern hydrometallurgy, the temperature is only about $, and the temperature can reach% in very few cases. Hydrometallurgy includes processes of leaching, purification and preparation of metals.

1. Leaching of ore or concentrate with appropriate solvents, so that the metal to be extracted into a solution of some ion (cation or complex anion) form, while the gangue and other impurities do not dissolve, such process is called leaching. After leaching, the leaching solution containing metal (ions) and the insoluble residue from the gangue mineral (leaching residue) were obtained after being cleaned and filtered. For some refractory ores or concentrates, preparatory treatment is often needed before leaching so that the extracted metals are converted to some kind of compounds or salts that are easily leached. For example, sulfated roasting, which is converted to soluble sulfate.

Both are commonly used preparation methods.

1. During the leaching process, some metal or nonmetallic impurities are often entered into the solution with the extracted metal, and the process of removing these impurities from the solution is called purification.

2, preparation of metal replacement, reduction, electrodeposition and other methods to extract metal from the purification process.

Electrometallurgy

Electrometallurgy is a method of extracting metals by using electrical energy. According to the difference of electric energy effect, electrometallurgy is divided into electrothermal metallurgy and electrochemical metallurgy.

1, electrothermal metallurgy is a method of making electricity by changing electric energy into heat energy. In the course of electrothermal metallurgy, according to the substance of its physical and chemical changes, there is little difference from the process of fire metallurgy. The main difference between the two is that the source of heat energy is different in the process of smelting.

2, electrochemical metallurgy (electrolysis and electrodeposition) uses electrochemical reaction to precipitate metals from solution or melt containing metal salts. The former is called solution electrolysis, such as electrolytic refining of actinides and electrodeposition of zinc, which can be included in hydrometallurgy; the latter is called molten salt electrolysis, which not only uses the chemical effects of electric energy, but also uses electric energy into heat to heat metal salts to melt, so it can also be classified into a kind of fire metallurgy. The production process of metal extraction from ore or concentrate is often a process of both fire and wet process. Even if the process flow is based on fire method, for example, the process of fire smelting in the vulcanizing pot concentrate, the process of electrolytic refining is necessary, and the zinc sulfide concentrate also needs high temperature in the wet process of zinc smelting. The raw materials are treated by oxidation roasting.