in this research work, the zinc extraction was investigated, using bioleaching process from a low grade zinc concentrate which was produced from the accumulated flotation tailings. zinc content was initially upgraded to 11.97% by flotation process. bioleaching experiments were designed and carried out by a mixed culture of acidithiobacillus ferrooxidans, acidithiobacillus thiooxidans, leptospir...

Mineral ores are full of metals, some very precious – but how to extract them? The Hamersley mines in the Pilbara in Western Australia contain such rich iron ore that it can almost be welded as it comes out of the ground. Traditionally, metals are extracted by ‘smelting’ or pyrometallurgy, the thermal treatment of minerals and metallurgical ores and concentrates to bring about physical and chem...

The use of recoverable sulfur particles will enhance the feasibility and reduce the cost of bioleaching process. Three different forms of sulfur particles, powder, pastilles and pellets were used to study the utilization and recovery of sulfur, used as energy source for thiobacilli in the bioleaching process. The Langmuir isotherm was used to explain the adsorption equilibrium existing between ...

Bioleaching, a novel biotechnological process, is used to eliminate heavy metals from contaminated sediments by acidification as well as solubilization of heavy metals. Metals from poor-quality ore and mineral compounds are removed by Bioleaching process, which is simple and low cost effective technology. Acidophilic sulfur oxidizing bacteria (Acidithiobacillus ferrooxidans, Acidithiobacillus t...

In an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment (WEEE), this research evaluated the bioleaching efficiency of gold (Au), copper (Cu) and nickel (Ni) by two strains of Aspergillus niger in the presence of gold-plated finger integrated circuits found in computer motherboards (GFICMs) and cellular phone printed circuit boards (PCBs). Th...

Bioleaching has been employed commercially to recover metals from low grade ores, but the production efficiency remains to be improved due to limited understanding of the system. This study examined the shift of microbial communities and S&Fe cycling in three subsystems within a copper ore bioleaching system: leaching heap (LH), leaching solution (LS) and sediment under LS. Results showed that ...

Bioleaching of heavy metals from contaminated soil using Penicillium chrysogenum strain F1 was investigated. Batch experiments were performed to compare leaching efficiencies of heavy metals between one-step and two-step processes and to determine the transformation of heavy metal fractions before and after bioleaching. The results showed that two-step process had higher leaching efficiencies o...

Leptospirillum sp. str. ZC isolated from bioleaching pulp of zinc concentrate is capable of oxidizing Fe (II) with the optimal temperature of 37oC. In pure culture bacteria is unable to oxidize pyrite, however, its growth together with sulfur oxidizing A.albertensis str.SO-2 significantly enhances the efficiency of pyrite bioleaching. The correlation between pyrite biooxidation and adhesion of ...

A specific and very sensitive dot-immunobinding assay for the detection and enumeration of the bioleaching microorganism Thiobacillus ferrooxidans was developed. Nitrocellulose spotted with samples was incubated with polyclonal antisera against whole T. ferrooxidans cells and then in I-labeled protein A or I-labeled goat antirabbit immunoglobulin G; incubation was followed by autoradiography. S...

BACKGROUND Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. This technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. So far the most studied microorganism in bioleaching is Acidithiobacillus ferrooxid...