The Effect of Basicity and Calcium Fluoride on Glass-Ceramic Production and Iron Recovery from Copper Slag

摘要

Glass-ceramics can be prepared and the iron can be effectively extracted from iron-rich copper slag in the same process to achieve the comprehensive utilization of the solid wastes. However, it is a great challenge to get the glass-ceramics with good properties and the iron with low sulfur concentration at the same time. In this paper, the effects of basicity and calcium fluoride on sulfur content of the obtained iron and production of the glassceramics from copper slag are investigated. The sulfur content of the recovered iron is determined by carbon sulfur analyzer, and the as-prepared glass-ceramics are characterized by DSC, XRD, and SEM. The results show that with the increase in the basicity, the sulfur content of the recovered iron greatly decreases, while the properties of the as prepared glass-ceramics firstly increase and then decrease, reaching the maximum value for the basicity of 0.6. The crystalline phases of the glass-ceramics are anthorite, diopside, wollastonite, and gehlenite, and the increase in the basicity favors the formation of gehlenite. The substitution of CaF2 for CaO obviously increases the sulfur content of the recovered iron. Moreover, the increase of CaF2 increases the crystal size and negatively affects the properties of the glass-ceramics.