Bioleaching, or microbial ore leaching, is a process used to extract metals from their ores using bacterial micro-organisms. The bacteria feed on nutrients …
It can therefore be concluded that leaching Zn stants for bioleaching were 1.4-, 9.4-, 4.3-, and 6.8-fold from the sewage sludge was dominated by the chemical higher than those of chemical leaching for Zn, Cu, Pb, and leaching.
Bioleaching and bio-oxidation processes are alternatives to conventional smelting processes, which discharge large amounts of carbon dioxide, sulfur dioxide, and various toxic materials such as arsenic. The overall advantages of integrating bio-leaching into mining strategies, in addition to sustainability and maintenance are listed below.
Acidithiobacillus thiooxidans FG -01 strain and chemical leaching. The spent catalyst is a hazardous waste due to the presence of organochlorine compounds, petroleum hydrocarbons, and heavy metals. Chemical leaching tests were performed with solutions of citric acid (20 g …
In general, bioleaching is cleaner and safer for the environment than chemical processing. However environmental pollution with toxic products, like sulfuric acid from the pyrite leaching, and heavy metals is still possible. Another drawback of microbial leaching is the slow rate at which microbes work.
the safe disposal of spent catalyst. The leaching yields and fractionation behavior of metals during chemical leaching was found to be identical. The results of the present study strongly suggest that bioleaching is an effective method for removing metals from the spent catalyst. Keywords Bioleaching.Fractionation .Metals.Spent catalyst 1 ...
Leaching vs Extraction The difference between leaching and extraction can be explained in terms of the chemical principles used in these two processes. Both leaching and extraction refer to the isolation of one or several compounds from a mixture that they are originally present in.
The results showed that except for Zn, the microbial leaching achieved higher removal efficiencies than the chemical leaching with As, Cu, Mn, and Fe after 300 h of incubation. It was observed that 95% Mn, 38% Cu, 67% Zn, 41% As, and 47% Fe were removed from the mine tailings by the microbial leaching …
At present bioleaching is used essentially for the recovery of copper, uranium and gold, and the main techniques employed are heap, dump and in situ leaching. Tank leaching is practised for the treatment of refractory gold ores.
Bioleaching - Wikipedia, Fe 3+ ions are used to oxidize the ore, but also the regeneration of the chemical oxidant Fe 3+ from Fe 2+, Pyrite leaching .
Bioleaching of chalcopyrite By Woranart Jonglertjunya A thesis submitted to The University of Birmingham ... including the chemical leaching of chalcopyrite by sulphuric acid and ferric sulphate solutions, bioleaching of ... bioleaching time as described in the SEM analysis of the bioleaching …
metals from ores. Although bioleaching is an environmentally-friendly alternative to chemical leaching, one of the principal shortcomings is the slow rate of leaching which needs to be addressed. The application of ultrasound in bioleaching, termed sonobioleaching, is a technique which has
A comparison of bioleaching efficiency and the results of sequential extraction shows that bioleaching can be used to remove elements which are in an exchangeable form or are bound to carbonates, meaning that they are bound in bio-available forms.
Although bioleaching generally requires a longer period of operation compared to chemical leaching, these results suggest that bioleaching by A. niger may be an alternative or adjunct to ...
bioleaching or leaching with cell-free spent medium at releasing rare earths from monazite, indicating that compounds other than the identiﬁed organic acids contribute to leaching performance.
Jarosite precipitation, a com- bioleaching and chemical leaching with addition of 0.1 M and mon component in chalcopyrite passivation coating, is believed to 0.25 M Fe3+ in shake flasks subjected to 8500-lux and 0-lux light inhibit the rate of copper dissolution by decreasing the concentra- conditions.
effect on the bioleaching and chemical leaching of realgar (As 2 S 2). Hu et al.  added 0.32g of silver ions, 4 grams of Ag 2 S, and 20 grams of Ag-C to each kilogram of chalcopyrite. After bacterial leaching in a shake flask for 20 days, the copper leaching rates were increased from 25% (without
· Comparison of chemical leaching and bioleaching of nickel from nickel . Gold solubilisation by the cyanide producing bacteria Chromobacterium Adhesion of microorganism cells and jarosite particles on the mineral surface (Sadowski, Z.).
· Bioleaching processes in mechanically-agitated tanks are usually applied for the minerals and exposing the gold for subsequent leaching, including roasting, Mintek has developed a considerable understanding of the chemical and
The surface characterizations have been done for samples before and after biological and chemical leaching. The SEM images illustrated that the minerals surfaces were smooth before processing, while they covered with an ash layer after biological treatment.
In bioleaching of pyrite there is an initial chemical leaching where Fe 3+ oxidises the mineral: 4FeS 2 + 4Fe 2 (SO 4 ) 3 → 12Fe(SO 4 ) + 8S The ferrous sulphate and elemental sulphur formed is then oxidised with the aid of microbes according to the following reactions:
The continuous bioleaching of a sphalerite concentrate, assaying 51.4% Zn, 1.9% Pb, 31.8% S and 9.0% Fe with mesophile iron and sulphur-oxidizing bacteria followed by chemical leaching of the bioleaching residue were assessed.
In addition, the biooxidation process and chemical-leaching process during the whole bioleaching process of PCBs were investigated and compared to confirm the role of bacteria in bioleaching of PCBs. Besides, the toxic effect of PCBs on bacteria was investigated.
Biological leaching of fly ash from municipal waste incineration by Aspergillus niger was examined in batch cultures and compared with chemical leaching. A. niger grew in the presence of up to 10% (w/v) of fly ash in the medium. In the presence of fly ash A. niger produced gluconate, whereas in its absence citrate was produced.
The Scientific World Journal is a peer-reviewed, Open Access journal that publishes original research, reviews, and clinical studies covering a wide range of subjects in science, technology, and medicine. The journal is divided into 81 subject areas.
· Bioleaching and chemical leaching as an integrated process in the . This work sought to integrate bioleaching and chemical leaching as a cost-effective process to treat zinc sulphides. The continuous bioleaching of a sphalerite
Abstract Chemical and biological leaching is practiced on a commercial scale for the mining of metals from ores. Although bioleaching is an environmentally-friendly alternative to chemical leaching, one of the principal shortcomings is the slow rate of leaching which needs to be addressed.
A theoretical analysis indicates that the leach rate of uraninite at 70 °C is around twelve times higher than that at 35 °C. The use of bioleaching as a cost-effective alternative to conventional oxidative leaching processes is being evaluated.
Chemical Leaching It can be seen from Figure 1 that 95% of copper was solubilized with 1.5% concentration of citric acid. This greater recovery of copper might be due to the formation of copper citrate complex in the solution (Mulligan, Kamali, and Gibbs 2004 Mulligan, C. A., Kamali, M., and Gibbs, F. B., 2004, "Bioleaching of heavy ...
The course of pH changes in biological and chemical leaching solutions is different from each other. Explanation for the effects of pH changes observed in samples containing H 2 SO 4 or 9K medium inoculated with bacteria, is a different course of reactions occurring in both systems. In the H 2 SO 4 test, chemical leaching process may occur.
Mechanism of bioleaching: The mechanism of bioleaching is rather complex and not well understood. The chemical transformation of metals by microorganisms may occur by direct or indirect bioleaching. Direct bioleaching: In this process, there is a direct enzymatic attack on the minerals (which are susceptible to oxidation) by the microorganisms.
Fungal bioleaching could be more environmentally friendly than bacterial and acid leaching for metal removal and recovery from spent LIBs. Biological Leaching and Chemical Precipitation Methods for Recovery of Co and Li from Spent Lithium-Ion Batteries - ACS Sustainable Chemistry & Engineering (ACS Publications)