Improving Beneficiation of Copper and Iron from Copper Slag by Modifying the Molten Copper Slag

Abstract

Abstract:In the paper, a new technology was developed to improve the beneficiation of copper and iron components from copper slag, by modifying the molten slag to promote the mineralization of valuable minerals and to induce the growth of mineral grains. Various parameters, including binary basicity, dosage of compound additive, modification temperature, cooling rate and the end point temperature of slow cooling were investigated. Meanwhile, optical microscope, scanning electron microscope and energy dispersive spectrometer (SEM-EDS) was employed to determine the mineralogy of the modified and unmodified slag, as well as to reveal the mechanisms of enhancing beneficiation. The results show that under the proper conditions, the copper grade of rougher copper concentrate was increased from 6.43% to 11.04%, iron recovery of magnetic separation was increased significantly from 32.40% to 63.26%, and other evaluation indexes were changed slightly, in comparison with unmodified copper slag. Moreover, matte and magnetite grains in the modified slag aggregated together and grew obviously to the mean size of over 50 µm, resulting in an improvement of beneficiation of copper and iron.

A Study on Reduction of Copper Smelting Slag by Carbon for Recycling into Metal Values and Cement Raw Material

“…Physical separation is an appropriate method for the recovery of iron from copper slag, but the recovery rate with magnetic separation is lower by about 40% due to its difficult processing of fayalite. Therefore, most studies have conducted roasting-magnetic separation to recover iron from the copper slag, and the recovery rate with this method obtained about 80% [12][13][14]. The roasting-magnetic process involves a reduction process by a reducing agent and converting from the main phase as fayalite to calcium silicates and magnetite by mixing fluxes as CaO added at a high temperature of about 1050-1300 • C [15,16], and then magnetic separation is used to recover iron from roasted slag after a cooling process.…”

Recovery of iron from red mud by high-temperature reduction of carbon-bearing briquettes

“…In recent years, direct reduction and magnetic separation technology has been developed to treat iron-bearing wastes such as copper and chromium slags, pyrite cinder, and red mud (Long et al, , 2016Chun, Long, and Li et al, 2015;Guo et al, 2016). During reduction roasting, iron oxides are reduced to metallic iron, which could be upgraded by magnetic separation.…”

A Study on Reduction of Copper Smelting Slag by Carbon for Recycling into Metal Values and Cement Raw Material

“…Chemical analysis both of the produced slag and Blast-Furnace slag show that the major oxides as the CaO, SiO2, MgO and Al2O3 are contained up about 95% of the total in accordance with requirements of BFS for cement material, as shown in Table 5. The application and recycling of the BFS for cement and concrete materials were also developed about 100 years ago with attention paid to effective utilization of a slag in steel industry [16,17]. Therefore, the produced slag with upto 15 wt.% of CaO additives seems that is achievable as a raw material for Portland cement.…”