Selective reduction and pyrometallurgical extraction of iron from copper production sludge

Copper production is connected with the formation of a large amount of slag which is practically never used in the construction industry due to the increased content of iron oxides. Extraction of iron from these wastes will allow to process the accumulated slag heaps in order to produce two commercial products such as iron-based alloys and building sand. The object of the study was the slag of the Karabash copper plant which was produced during flotation decoppering. The possibility of solid carbothermal reduction of iron from fusible slags of copper smelting production was shown using low-grade thermal coal as a reducer and iron extraction separation melting. Phase and chemical compositions of slags are considered, the initial melting point and the size distributionare set. Experiments on the reduction of iron in the Tamman furnace are made using two options: 1) the reduction of iron from the slurry by lump coal; 2) restoration of briquetted samples prepared from the slurry and coal in fractions less than 1 mm. Features of the reduction process for both options are described, the metallization degree being about 90 %.The recycled material was separated by melting into an iron-based alloy in the form of compact metal and slag. Depending on smelting separation conditions (temperature, time, crucible type) steel, iron or ferrosilicium can be produced. The resulting metal comprises about 1 % copper, the sulfur content ranges from 0.1 to 2 % depending on the resulting alloy. The oxide produced in the form of slag with a low content of iron oxides issuitable for use in the building industry.