Summary What is Biomining? Biomining is a technique we can use to extract metals from their ore using prokaryotes and fungi. Therefore, this is a biological treatment method that uses living organisms. In this process, microorganisms secrete organic compounds that can chelate the metals in the metal ore.
|Published (Last):||9 February 2012|
|PDF File Size:||9.83 Mb|
|ePub File Size:||4.98 Mb|
|Price:||Free* [*Free Regsitration Required]|
Leaching Process There are three commercial methods used in leaching: i Slope Leaching. About 10, tonnes of ores are ground first to get fine pieces. It is dumped in large piles down a mountain side leaching dump.
Water containing inoculum of Thiobacillus is continuously sprinkled over the pile. Water is collected at bottom. It is used to extract metals and generate bacteria in an oxidation pond. The ore is dumped in large heaps called leach dump. Further steps of treatment are as described for slope leaching. In this process ores remain in its original position in earth. Surface blasting of rock is done just to increase permeability of water. Thereafter, water containing Thiobacillus is pumped through drilled passage to the ores.
Acidic water seeps through the rock and collects at bottom. Again from bottom water is pumped, mineral is extracted and water is reused after generation of bacteria. Examples of Bioleaching Fig. Microbial leaching of copper. Bioleaching has been discussed with copper, uranium, gold, silver and silica. Copper Leaching Throughout the world copper leaching plants have been widely used for many years.
It is operated as simple heap leaching process or combination of both heap leaching and in situ leaching process. Dilute sulphuric acid pH 2 is percolated down through the pile.
The liquid coming out of the bottom of pile reach in mineral. It is collected and transported to precipitation plant, metal is reprecipitated and purified. Liquid is pumped back to top of pile and cycle is repeated. Several other metals are also associated with these ores.
Sulphuric acid is added to maintain pH. An outline of microbial leaching of copper is shown in Fig. Microbial leaching of copper has been widely used in the USA. In the USA tonnes of copper is recovered per day. Uranium Leaching Uranium leaching is more important than copper, although less amount of uranium is obtained than copper.
For getting one tonne of uranium, a thousand tonne of uranium ore must be handled. In situ uranium leaching is gaining vast acceptance. Silver is more readily solubilized than gold during microbial leaching of iron sulfide. Silica Leaching Magnesite, bauxite, dolomite and basalt are the ores of silica. Mohanty et al isolated Bacillus Ucheniformis from magnesite ore deposits.
Later it was shown to be associated with bioleaching, concomitant mineralysis and silican uptake by the bacterium. It was concluded that silican uptake was restricted adsorption of bacterial cell surface rather than internal uptake through the membrane.
The bioleaching technology of silica magnesite by using B. More in this section.
Difference Between Biomining and Bioleaching
Part of the Applied Environmental Science and Engineering for a Sustainable Future book series AESE Abstract Universal reserves of high-grade ores are diminishing at an alarming rate due to the rapid increase in the demand for metals. Biomining is the extraction of specific metals from their ores through biological means, usually microorganism. Biomining is done in two steps often called bioleaching and biooxidation. Bioleaching commonly refers to biomining technology applied to base metals; whereas, biooxidation is normally applied to sulfidic-refractory gold ores and concentrates. The biomining methods are affordable, nontoxic, effective, and likewise environment pleasant.
Biomining and Bioleaching
JoJogul Other uses of biomining New biomining techniques that do not involve oxidation are being tested, which would enable large-scale biomining for different types of minerals and metals. Biomining is an environmentally friendly technique compared to typical mining. Most current biomining operations use naturally occurring microbial communities. This risk can be managed by ensuring that biomining is conducted under controlled conditions with proper sealing and waste management protocols. Microbes are especially good at oxidizing sulfidic minerals, converting metals like iron and copper into forms that can dissolve more easily.
Bioleaching and Biomining