The process of extracting copper from copper ore mainly includes pyrometallurgy and hydrometallurgy, with pyrometallurgy being the predominant method for copper smelting. The principle of pyrometallurgical copper smelting is to use high-temperature oxidation-reduction reactions to convert copper-containing substances into pure metallic copper, primarily suitable for sulfide copper ores with higher sulfur content.
The steps involved in pyrometallurgical copper smelting are as follows:
1. Select appropriate sulfide copper ores, which undergo pre-treatment such as leaching and concentration to obtain a refined concentrate.
2. Mix the refined concentrate with coke and place it into a pyrometallurgical reactor, where it undergoes oxidation-reduction reactions at high temperatures. The produced SO2 gas is processed through cooling, washing, and other procedures before emission.
After several iterations of this process, relatively pure metallic copper is obtained.
Hydrometallurgical extraction of copper, also known as heap leaching or solution mining, essentially uses metals more reactive than copper (excluding K, Ca, Na) to displace less reactive metals. For example, adding zinc or iron to a copper sulfate solution can displace metallic copper.
The main steps in hydrometallurgical copper extraction include:
Leaching: Place iron in a copper sulfate solution, causing the copper ions in the solution to be displaced by iron and precipitate as elemental copper.
Collect the precipitated copper powder, then smelt it further to obtain pure copper.
Additionally, the processing of copper ores involves preparatory steps such as crushing, screening, grinding, and classification to prepare the ore for subsequent smelting processes. These steps ensure that the ore reaches the appropriate particle size and purity for smelting.
In summary, the process of extracting copper from ores is a complex and precise technology involving various methods and steps to ensure the final product is of high-purity metallic copper.
