Bioleaching and selective biorecovery of zinc from zinc metallurgical leach residues from the Três Marias zinc plant (Minas Gerais, Brazil)

Abstract

BACKGROUND Gradual depletion of high‐grade ores for heavy metals has encouraged industries to search for alternative methods to recover metals. Wastes generated from metallurgical industries can be used as a secondary resource as it contains high concentrations of metals. RESULTS The bioleaching kinetics and biorecovery of zinc from Zn‐plant leach residues (ZLR), collected from a currently operating Zn‐plant in Três Marias (Minas Gerais, Brazil) were investigated using sulfuric acid producing Acidithiobacillus thiooxidans (A. thiooxidans). Response surface methodology (RSM) with full factorial central composite design (CCD) was applied to optimize Zn bioleaching by A. thiooxidans. The experiments were performed by varying the initial elemental sulfur concentration (5–30 g L−1), pulp density (5–50 g L−1) and initial pH (3.0–4.0 pH units). More than 75% of Zn was extracted from ZLR by A. thiooxidans under optimized conditions (sulfur concentration 25.1 g L−1, pulp density 21.5 g L−1 and initial pH 3.3). The leaching efficiencies of culture supernatant (biogenic sulfuric acid) and chemical sulfuric acid were compared to understand the leaching kinetics. The Zn leaching kinetics of ZLR followed the shrinking core diffusion model. Zn was selectively recovered from the Fe‐rich acidic bioleachate by biogenic sulfide precipitation. Fe was first removed (more than 85% of total Fe in the leachate) by adjusting the initial pH to 5.0, followed by selective Zn biorecovery. CONCLUSIONS Zn (>95%) was selectively recovered from Fe‐depleted ZLR by biogenic sulfides (with 1:1, Zn:biogenic sulfide mass ratio). Biohydrometallurgy can be a potential alternative resource recovery strategy for the selective recovery of Zn from ZLR. © 2016 Society of Chemical Industry

Expanding beyond canonical metabolism: Interfacing alternative elements, synthetic biology, and metabolic engineering

“… [183] Zinc A 75% Zn extraction was obtained from Zn-plant leach residues under optimized conditions Bioleaching Acidithiobacillus thiooxidans Sethurajan et al. [184] …”

Integration of microbial and chemical processing for a sustainable metallurgy

“…Depletion of primary reserves of metals has shown unprecedented growth in the recycling of metals from divergent secondary/spent/waste materials, which have also been explored with the aid of bio‐chemical processing in recent years . Useful research carried out in this direction is summarized in Table . Some of the important contributions with possible potential to achieve sustainability are discussed in this section.…”

“…Depletion of primary reserves of metals has shown unprecedented growth in the recycling of metals from divergent wileyonlinelibrary.com/jctb 79 secondary/spent/waste materials, which have also been explored with the aid of bio-chemical processing in recent years. 15 Useful research carried out in this direction is summarized in Table 2.…”

Bioleaching of Iron and Zinc from a galvanized steel waste from automotive industry using Acidithiobacillus thiooxidans: a case of study of the bajío area in México

“…Additional authors have explored the use of A. thiooxidans in the recovery of metals from residues of the mining industry. An example of this is the work of Nguyen et al (Nguyen et al, 2015) regarding bioleaching of Cu, Mn, Zn and As from mine tailings, and the study conducted by Sethurajan et al (Sethurajan et al, 2016) related to the biorecovery of Zn from zinc plant leach residues. A report also exists on the use of this bacterium species in the recovery of copper, lead and zinc from printed wire boards (Wang et al, 2009), either as a pure culture or as a mixed culture along with A. ferrooxidans, showing promising results.…”