Development of a Sustainable Metallurgical Process to Valorize Copper Smelting Wastes with Olive Stones-Based Biochar

Abstract

Flue dust waste coming from a copper (Cu) smelting company has been valorized using a newly developed metallurgical process with the aim of recovering a dust concentrated in valuable metals, such as lead (Pb) and zinc (Zn), and studying the feasibility of replacing anthracite with biochar as reducing agent. Metallurgical trials using different mixtures of reducing agents have been performed in a furnace at 1400 °C. This furnace employs a high-power thermal plasma (HPTP) system as energy source. Using copper as the base metal, pellets containing a mixture of the waste, different reducing agents, and binder were introduced into the furnace for their dissolution. Recovery yields in the range of 45–85 wt.% for Pb and Zn were obtained in the flue dusts. All the trials proved the effectiveness of the developed process to enrich the flue dusts in valuable metals, including those only using biochar as reducing agent. Further trials will be carried out in order to better control the parameters involved in the metallurgical process developed and improve its efficiency.

Determining the Reactivity of Selected Biomass Types Considering Their Application in Pyrometallurgical Processes of Metal Production

“…Among high-temperature procedures of copper slag processing aimed at valuable metal recovery, reduction processes with coke as a reducer are of the greatest importance. In addition, for several years, there have been attempts to apply alternative reducers, such as various types of biomass or carboniferous waste generated in the coal enrichment processes [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ].…”

Extraction of Pb, Cu, Zn and As from Fine Dust of Copper Smelting Industry via Leaching with Sulfuric Acid

“…The chemical composition of fine dust from the copper smelting industry depends mainly on the smelting process conditions and the type and composition of the concentrate. Minor deviations of the furnace operating modes, the chemical composition of the concentrate and other factors from the specified parameters can lead to changes in the metal content in the dust [11][12][13][14][15][16]. Dust from copper smelters is characterized by a heterogeneity of particle size, chemical and mineralogical composition [17][18][19], which must be taken into account when choosing a technology for processing the dust of a specific composition.…”