Study on Mechanism of Oxidation Modification of Copper Slag

The pyrometallurgical processing of copper concentrates generates large amounts of iron and copper-containing slag. It is an available way to separate and recover iron and copper by oxidative modification slag. The copper slag used in this experiment is water-quenched copper slag tailings. The method of the experiment is to separate copper and iron in the copper slag by oxidation-magnetic separation method, and the amount of copper and iron recovered in the later stage is also greatly reduced. Mineralogical phase transform of copper slag during oxidation modification process has been investigated with the goal to provide valuable information for the recovery of copper and iron. The influence of temperature and time on the mineral phase transformation has mainly been studied during the oxidation modification. XRD combined with FT-IR has been used to characterise the mineral phase change. The experimental results showed that the oxidation temperature and time were favorable for modification of copper slag under medium- and low-temperature conditions. When the oxidation temperature was 950 degrees C, fayalite was transformed to hematite and quartz, which provided the necessary conditions for separating iron and silicon, and copper embedded in fayalite was also released. In addition, the copper slag particles were significantly grown under the action of oxidation reaction which was also beneficial to subsequent selection and treatment.