Recovery of γ-Fe₂O₃ from copper ore tailings by magnetization roasting and magnetic separation

Abstract

To comprehensively reuse copper ore tailings, the recovery of γ-Fe2O3 from magnetic roasted slag after sulfur release from copper ore tailings followed by magnetic separation is performed. In this work, after analysis of chemical composition and mineralogical phase composition, the effects of parameters in both magnetization roasting and magnetic separation process with respect to roasting temperature, residence time, airflow, particle size distribution, magnetic field intensity, and the ratio of sodium dodecyl sulfonate to roasted slag were investigated. Under optimum parameters, a great number of γ-Fe2O3 is recycled with a grade of 66.86% and a yield rate of 67.21%. Meanwhile, the microstructure, phase transformation and magnetic property of copper ore tailings, roasted slag, and magnetic concentrate are carried out.

Preparation and Crystallization of Magnetic Glass‐Ceramics from the Residues after Sulfur Release and Iron Recovery from Copper Ore Tailings with Varied CaO Content

“…In order to actively respond to the call for comprehensive utilization of COT, a systematic approach for the successive release of sulfur and the recovery of iron by a linear route, including oxidation roasting and magnetic separation, were investigated in our previous study. [2] We showed that sulfur could be released in a first step, followed by iron recovery. However, this process generates residues after sulfur release and iron recovery.…”

“…Residues collected from a previous study have been used as raw material in this study. [2] The residues were produced successively through a series of treatments including oxidizing roasting, sulfur release and magnetic separation of the copper ore tailings in optimum conditions. The residues as samples were grounded into powders below 200 meshes and dried at 105 � 2 °C for 24 h. The main chemical components with more than 0.4 wt.% are shown in Table 1 Based on the CaOÀ FeOÀ SiO 2 phase diagram [25] shown in Figure 1, three groups of formulations were designed and labelled as BZ-0 wt.%, BZ-5 wt.% and BZ-10 wt.%.…”

“…It was estimated that approximately 400 t of COT were produced for 1 t of copper. [1,2] COT contain several valuable resources, such as sulfides (SO x ), iron oxide, aluminum oxide, silicon oxide and other trace amounts of components. It has previously been suggested that COT could be recycled and thus utilized.…”