Crushing and grinding

Crushing and grinding are the primary technological processes of the beneficiation process. The raw ore enters the ball mill after being crushed, and the mill will accept the crushed product at a controllable feed rate, and enter the next production process after finally reaching the qualified particle size. In hydrometallurgy, a certain amount of water needs to be added to the mill to maintain the density of the mill.

Leaching

Leaching is to select a suitable solvent to selectively dissolve valuable metal elements or harmful impurities in ores, concentrates or smelting intermediate products, and transfer them into the solution to achieve the purpose of separating valuable elements from harmful impurities or gangues. In addition to ores and concentrates, the leaching materials may also be residues after smelting, anode slime, waste alloys, etc.

Ore and concentrate are usually composed of a variety of minerals, the composition is very complex, and the valuable elements often exist in compounds such as oxides, sulfides, arsenides, carbonates, sulfates, and phosphates. It also exists in the form of metals, such as gold, silver, natural copper and so on. The appropriate solvent and leaching method must be selected according to the characteristics of the raw material.

Washing and extraction

The purification of the solution from leaching is the process of separating the target metal from impurities in the solution and removing harmful impurities in the leaching solution. During the leaching process of ore or concentrate, when the target metal is transferred from the raw material to the solution, certain impurities will also enter the solution.

In order to facilitate precipitation and extraction of the metal of interest, certain impurities must be removed prior to precipitation in order to obtain a solution as pure as possible. The purification of leaching solution is relative. The impurity metals separated by purification are often important raw materials to be recovered as valuable semi-products.

Electrowinning

The operation process of separating and recovering the metal materials contained in the aqueous solution through the conversion of the metal state from the solution is one of the important steps of hydrometallurgy. There are two methods of extracting metals from solution: electrolytic method and chemical method.

Electrolytic extraction, also known as electrolytic deposition, is a process in which some metals are deposited on the cathode by passing direct current into an aqueous solution or suspension containing metal salts.

Chemical extraction is the process of reducing metal ions in aqueous solution to metals with a reducing agent.