Industrial Heap Bioleaching of Copper Sulfide Ore Started with Only Water Irrigation

Abstract

Sulfuric acid solution containing ferric iron is the extractant for industrial heap bioleaching of copper sulfides. To start a heap bioleaching plant, sulfuric acid is usually added to the irrigation solution to maintain adequate acidity (pH 1.0–2.0) for copper dissolution. An industrial practice of heap bioleaching of secondary copper sulfide ore that began with only water irrigation without the addition of sulfuric acid was successfully implemented and introduced in this manuscript. The mineral composition and their behavior related to the production and consumption of sulfuric acid during the bioleaching in heaps was analyzed. This indicated the possibility of self-generating of sulfuric acid in heaps without exogenous addition. After proving by batches of laboratory tests, industrial measures were implemented to promote the sulfide mineral oxidation in heaps throughout the acidifying stages, from a pH of 7.0 to 1.0, thus sulfuric acid and iron was produced especially by pyrite oxidation. After acidifying of the heaps, adapted microbial consortium was inoculated and established in a leaching system. The launch of the bioleaching heap and finally the production expansion were realized without the addition of sulfuric acid, showing great efficiency under low operation costs.

Yard phytoarchitecture for onsite sanitation of household wastewater containing copper

“…Microbial treatments can extract or recover copper from ores, waste materials, or industrial processes. This method, known as bioleaching [24] or biomining, is an environmentally friendly alternative to traditional copper extraction techniques such as smelting or roasting. The selection of microorganisms generally uses certain types of bacteria, archaea, or fungi because of their ability to interact with copper ore. Microorganisms acidithiobacillus ferrooxidans (23) are the most commonly used microorganisms, which oxidize metal sulfides to soluble metal sulfates.…”

Osmotic response in Leptospirillum ferriphilum isolated from an industrial copper bioleaching environment to sulfate

“…In addition, bioleaching operations located in desert areas optimize the usage of water by constantly recirculating the solutions in the industrial circuit and thus, increasing the concentration of inorganic compounds and therefore the osmotic strength. Among all species of acidophilic prokaryotes identified in heap bioleaching operations, the most widely reported are members of Acidithiobacillus, Leptospirillum, Sulfobacillus, Ferroplasma and Acidiphilium genera (Demergasso et al, 2005;Schippers et al, 2014;Jia et al, 2021). These species have shown different osmo-tolerance level to osmotic strength produced by increasing chloride ions, thus their tolerance to sodium chloride (halo-tolerance) varies widely, with some of the "primary" (iron-oxidizing autotrophic) species being far less tolerant to chloride that some sulfur-oxidizers and heterotrophic species (Boxall et al, 2017;Corbett et al, 2022).…”

A Comparative Study on Bioleaching Properties of Various Sulfide Minerals Using Acidiphilium cryptum

“…Bioleaching is considered a green alternative to chemical leaching processes as it is a method of extracting metals through biologically produced metabolites [4]. If valuable metals in sulfide minerals are recovered using bioleaching, ore transportation costs can be reduced, and environmental pollution can be mitigated by recirculating the leaching solution [5][6][7]. The understanding of bioleaching, the application of microbial processes to extract metals from near-insoluble ores, has been rapidly established over the past few decades [8].…”