Separating and Recycling of Fe, Cu, Zn from Dumped Copper Slag by Microwave Irradiation Assisted Carbothermic Method

Abstract

Iron, copper and zinc were separated and recycled from dumped copper slag using a carbothermic method in the presence of microwave irradiation. Iron in the form of fayalite and magnetite in the slag was reduced to metal iron while zinc was evaporated and captured as zinc oxide powder. Results indicated that metallization rate of iron could reach 91.38~93.45 wt% and zinc recovery efficiency was 90.5 wt% when the new methodology was employed, and that reaction temperature was 100°C lower compared to that of traditional processes, reaction time of the new process was decreased by 90 min.

Copper Overview: From the Ore to the Applications – A Case Study of the Application of Concentrated Solar Energy to the Treatment of Copper Metallurgy Slags

“…Therefore, copper slag represents an environmental impact [39]: risks of heavy metals lixiviation, a visual impact, and sometimes occupation of cultivable areas. Moreover, research has also focused on the recovery of iron from the slag due to the high iron content in the copper slags: by using coke as a reductant of the copper oxide and the magnetite [40]; by modifying the molten slag with the purpose of promoting the mineralization of recoverable mineral phases and inducing the growth of the mineral phases [41]; by using a method based on coal, Direct Reduction Iron (DRI), and magnetic separation [42]; by means of a process based on aluminothermic reduction [43]; by reduction in an electric furnace with the objective of obtaining a Cu-Pb-Fe alloy [44]; by carbothermal reduction to transform the copper slag into pig iron and glassy material [45]; by irradiation with a microwave as a support of the carbothermal method [46]; or by reduction with coke powders and magnetic separation [47]. In the following section, we present a study about the application of concentrated solar energy to recover valuable metals from copper slags.…”

A multilevel sustainability analysis of zinc recovery from wastes

“…It carries the highest concentration among all the heavy metals such as copper, lead, chromium, cadmium and nickel in metallurgical industries, light industries, residential sector and recycled aggregates. Recovery of zinc and copper from secondary resources such as the infrastructural materials and alloys such as brass is usually via a series of pyrometallurgical reduction processes (Lee et al, 2016), microwave irradiation assisted carbothermic methods (Liao et al, 2016) and electrometallurgical processes (Robinson, 2016), etc., discussed in the following section.…”

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

“…The processing technologies are different depending on the metals to be recovered from copper slag. Hydrometallurgical treatment is widely used on copper recovery from copper slag that including direct leaching in sulphuric acid, leaching in sulphuric acid through H2S gas or ferric chloride [10,11], but leaching of the copper slag may be too expensive because it requires high consumption of strong acid and reagents, and very toxic. Magnetic separation and reduction smelting method are used to recover and separate the iron from copper slag.…”