Removal of Copper from the Sulphide Copper Smelting Waste Slag

The applicability of chloridizing roasting for removal of copper from the sulphide copper smelting waste slag of the ”Karabashmed'” copper-smelting plant is investigated. Calcium chloride CaCl2 was used as chlorination agent. It is established that the chlorinating roasting of the initial slag presented by fayalite 2FeO∙SiO2, hasn't led to noticeable removal of copper. Considerable degree of removal of copper (more than 90 %) has been reached as a result of the chlorinating of preliminary oxidized slag in which fayalite was oxidized to form Fe2O3 and SiO2. Using a fractional factorial experiment 23–1, dependence of degree of copper removal from preliminary oxidized slag upon temperature of the chlorinating roasting, time of isothermal roasting period and content of CaCl2 was established. It is found that increase of temperature and of CaCl2 content leads to increase in degree of copper removal. The influence of time of isothermal roasting period in the studied interval (2–4 h) is statistically insignificant.