Material composition of copper slag of the Almalyk copper-smelting plant (Uzbekistan)

Abstract

Relevance. Copper production is accompanied by release of a large volume of slag. Today, huge quantities of copper slags have accumulated all over the world, in which the copper content is even greater than that in original ores. The slags that result from the smelting of ores and concentrates of both ferrous and non-ferrous metals, together with other metallurgical wastes such as tailings, are increasingly the subject of significant environmental controversy. The only way to reduce the negative impact of slag waste on the environment can be their disposal, by complex extraction of valuable components from them and further use of slag waste for construction purposes. In addition to the main component of copper, copper slags contain elevated contents of gold, silver, zinc, iron, etc. The form of finding valuable metals such as iron, copper, lead and zinc in copper slags is complex. A detailed study of the mineral composition of slags is used in development of an effective technology for processing slags. Aim. To study mineral composition of copper slags, the form of finding valuable components. Object. Copper slag waste from the copper-smelting plant of the Almalyk MMC. Methods. Chemical composition of copper slags was established by phase analysis, atomic absorption, X-ray fluorescence research methods. Mineral composition of the ores was established as a result of complex studies, including: optical microscopy in transmitted and reflected light, X-ray diffraction, microprobe studies and electron microscopy. Results. Copper content in composition of copper slag samples is higher than in copper ores and it is 0.77–0.97%. In addition to copper, copper slags contain elevated contents of a complex of metals (g/t): Au – 0.17–0.26; Ag 8.42–10.64, Zn 4.288–10216, Pb – 2014-3360. Ferrous silicates (fayalite, ferrosillite), vitreous mass of ferruginous-silicate composition predominate in the composition of copper slags. Ore minerals are mainly represented by magnetite. The mineral content is approximately 10–15%. Among сopper sulfides minerals bornite, chalcocite, less often cubanite, chalcopyrite, covellite sharply predominate. Cuprite is observed in small amounts, and native copper is metallic. The mineral form of finding molybdenum is molybdenite. Among the native silver minerals, native silver was found in association with lead minerals. Gold is included in the composition of native copper and chalcocite as an impurity and passes into copper concentrate during processing slags.

Keywords

• copper slags
• chemical
• mineral composition
• form of location
• copper
• iron