bacterial leaching process indirect procees

Sociedad Minera Pudahuel bacterial thin-layer leaching ...

The thin-layer leaching process originally conceived and developed for leaching oxide ores has been successfully adapted to bacterial leaching of mixed and secondary sulphide ores. The process is currently being applied at the Socicdad Minera Pudahuel Lo Aguirre Plant.

(Bio)chemistry of bacterial leaching—Direct vs. indirect ...

Request PDF | (Bio)chemistry of bacterial leaching—Direct vs. indirect bioleaching | Bioleaching of metal sulfides is effected by bacteria, like Thiobacillus ferrooxidans, Leptospirillum ...

Leaching Process

2021-10-20 · Leaching Process Examples. An example of the leaching process would be the leaching of Al 2 O 3.2H 2 O (or bauxite) with a heated and concentrated solution of sodium hydroxide. In this example, the concentrated NaOH dissolves the aluminium present in the bauxite whereas the impurities such as Fe 2 O 3, TiO 2, and SiO 2, are not dissolved by ...

Bioleaching: A microbial process of metal recovery; A ...

The present review describes the historical development and mechanisms of bioleaching. Recent development has shown commercial application of the process and, concurrently, details pertaining to the key microorganisms involved in these processes have been …

(DOC) bacteria leaching | Syahid Hidayatullah

Bacteria leaching is process to extract ores from minerals by using microorganism to accelerate the process. A. Historical Background One of the first reports where leaching might have been involved in the mobilization of metals is given by the Roman writer Gaius Plinius Secundus (23– 79 A.D.).

Bioleaching and Biomining

2020-12-3 · Indirect bacterial leaching •In this process the microbes are not in direct contact with minerals, but bacteria produces strong oxidising agents such as ferric ion and sulfuric acid on oxidation of soluble iron or soluble sulfur respectively. •For indirect bioleaching, acidic environment is absolutely essential in order

Bacterial Leaching

2019-4-9 · Bacterial Leaching Biotechnology in the Mining Industry Preston Devasia and K A Natarajan Bacterial leaching is the extraction of metals from their ores using microorganisms. Microbial technology offers an eco­ nomic alternative for the mining industry, at a time when high-grade mineral resources are being depleted. Why Bacterial Leaching

Microbial leaching

2020-8-27 · According to equation 3, iron is dissolved through direct bacterial leaching. In addition to this leaching process performed only by micro-organisms, there is another process, ''indirect, bacterially supported leaching'', which takes place slowly in the absence of microbes. The oxidation of pyrite can be used as an example.

A review of sulfide minerals microbially assisted leaching ...

Bacterial assisted leaching processes are based on the ability of certain microorganisms to solubilize/or expose the metals contained in the ores and concentrates by direct oxidation, or through indirect chemical oxidation instigated by the corrosive metabolic by-products generated by an electrochemical option, or a combination of both of these.

BIOLEACHING & LEACHING: DEFINITION, IMPORTANCE …

2021-3-14 · Indirect bacterial leaching involves the production of chemical substances which chemically oxidizes the sulphide mineral; and the bioleaching bacteria do not need to be in direct physical contact with the mineral surface (as is applicable in direct bacterial leaching). Further reading. Jee C and Shagufta (2007). Environmental Biotechnology.

Leaching Process

b) Dump Leaching c) Heap Leaching d) Vat Leaching. Answer: b Clarification: Dump leaching involves uncrushed waste rock which is piled up. It is an industrial process to extract rare metal ores or copper. This process is similar to heap leaching but in case of dump …

microbial leaching of iron

Bacterial Leaching – Biotechnology in the Mining Industry. Bacterial leaching is the extraction of metals from their ores using microorganisms. … is further confirmed by the leaching of synthetic sulphides free of iron, … »More detailed

Bacteria Leaching | PDF | Chemical Elements | Atoms

2014-11-17 · Bacterial Leaching Bryner (1954) cooper in the effluent waters of the open-pit mining operations of the Bingham Canyon, Utah, was partially due to the action of bacteria present in the ore deposit. Ruzzle and Trussell (1963) the leaching operations in Rio Tinto, Spain, were partly due to …

Gold & Copper Bioleaching

2015-2-28 · Bacterial Leaching of Copper Ores. Several types of bacteria capable of living in an acid environment have been isolated from copper mine waters. The foremost of these are of the genus Thiobacillus (T.). Thiobacillus bacteria are acidophilic …

Bacterial Leaching to precious metals process

Bacterial Leaching to precious metals process Process which uses microorganisms for the recovery of precious metals from metal-containing processes and streams. This technology is targeted at using naturally-occurring, sulfate-reducing bacteria for the recovery of gold and silver from ores, instead of the more traditional — and more toxic ...

Direct and Indirect Bio-Leaching of Co and Ni from an Iron ...

In this research work, the bio-leaching of Co and Ni from an iron-rich laterite ore is assessed using the acidophilic heterotrophic (Delftia acidovorans)and autotrophic (Acidithiobacillus ferrooxidans) bacteria. The metabolic products of the acidophilic bacteria play an important role in bio-leaching. The results obtained from the indirect bio-leaching indicate the highest nickel recoveries of ...

(Bio)chemistry of bacterial leaching—direct vs. indirect ...

Bioleaching of metal sulfides is effected by bacteria, like Thiobacillus ferrooxidans, Leptospirillum ferrooxidans, Sulfolobus/Acidianus, etc., via the (re)generation of iron(III) ions and sulfuric acid.. According to the new integral model for bioleaching presented here, metal sulfides are degraded by a chemical attack of iron(III) ions and/or protons on the crystal lattice.

CA2663356C

A process for the indirect bioleaching of zinc sulphide is disclosed, and includes leaching, solvent extraction, electrowinning, and oxidant regeneration steps in a closed circuit. The leaching step utilizes ferric iron as an oxidant, the solvent extraction step utilizes di-2 ethylhexyl phosphoric acid (D2EHPA) as a solvent extraction reagent, the oxidant regeneration step includes the ...

Direct and Indirect Bio-Leaching of Co and Ni from an …

2021-10-26 · the indirect bio-leaching of Delftia acidovorans are, respectively, 29.84% and 23.75% higher than those for the direct bio-leaching, performed at 30 °C and 150 rpm of an incubator shaker for 30 days. For the indirect bio-leaching, the chemical control has a

Bacterial leaching

Direct versus indirect bioleaching - ScienceDirect

Bacterial Leaching of Metal Sulfides Proceeds by Two ...

The acid-insoluble metal sulfides FeS2, MoS2, and WS2 are chemically attacked by iron(III) hexahydrate ions, generating thiosulfate, which is oxidized to sulfuric acid. Other metal sulfides are attacked by iron(III) ions and by protons, resulting in the formation of elemental sulfur via intermediary polysulfides. Sulfur is biooxidized to sulfuric acid. This explains leaching of metal sulfides ...

Direct versus indirect bioleaching

2001-2-1 · 1.. IntroductionThe mechanism of bacterial leaching of sulfides has interested researchers for a long time, .While many parameters affecting the leaching process have been known as empirical factors, a more profound understanding of the heterogeneous mechanism of sulfide degradation has only gradually emerged as a consequence of advances in semiconductor electrochemistry, sulfide surface ...

A BACTERIAL HEAP LEACHING APPROACH FOR THE …

2009-8-26 · During sulphide heap leaching, bacterial activity can be utilised to catalyse the oxidation of iron, which acts as an electron carrier between the mineral and oxygen for the conversion of sulphides. Indirect or direct bacterial attack on sulphur species can also generate sulphuric acid, which can improve the acid balance, and exothermic heat,

Bioleaching: Extraction of Metals by Microorganisms ...

2020-6-1 · INDIRECT LEACHING (Non-contact leaching) In this type of biomining, there is no need of microbial attachment on the metal surface and the electrons are not gained by the metals directly from microbes, but the reduced metals are oxidized by taking …

A METHOD OF ADAPTATION OF A BACTERIAL CULTURE …

A leaching process according to claim 10, wherein the adaptation of the bacterial culture of step (i) adapts that bacterial culture to operate at a pH of about 5. 14. A leaching process according to claim 10, wherein the leaching of step (ii) is conducted at the same or similar pH to that to which the bacterial culture has been adapted in step (i).

Microbes and mineral recovery: Bioleaching of copper, …

2020-4-22 · There are two major mechanisms of bacterial leaching: 1) involves the ferric-ferrous cycle (indirect mechanism) 2) involves physical contact of the organism with the insoluble sulphide (direct mechanism). An important reaction mediated by Acidithiobacillus ferrooxidans is: 4FeSO₄+ O₂+ 2H₂SO₄→ 2Fe₂(SO₄)₃+ 2H₂O.

(PDF) Bioleaching: A microbial process of metal recovery ...

2021-10-27 · The thin-layer leaching process originally conceived and developed for leaching oxide ores has been successfully adapted to bacterial leaching of mixed and secondary sulphide ores.

Bacterial Leaching of Pyrite

2009-9-17 · bacterial leaching as a pre-treatment step for the extraction of gold from refractory ores and concentrates, offering potentially significant advantages over the conventional oxidative pre-treatment alternatives (Komnitsas and Pooley, 1989). Bacterial leaching has been shown in numerous dump and heap leaching situations to be

Bacteria Leaching Low Grade Ores

2016-12-9 · Bacteria Leaching Low Grade Ores. USING BACTERIA to leach and recover a metal from any metallurgical raw material with a ferric sulphate sulphuric acid lixiviant has been patented by Kennecott. Kennecott Copper Corp. just recently obtained a U.S. patent on bacteria leaching of ores containing sulphides and/or iron sulphate.

(PDF) Bacterial Leaching of Metal Sulfides Proceeds by Two ...

Bacterial Leaching of Metal Sulfides Proceeds by Two Indirect Mechanisms via Thiosulfate or via Polysulfides and Sulfur February 1999 Applied and Environmental …

Process for leaching copper from copper sulfide using …

1997-9-24 · The process comprises using an acid leaching solution that includes both or any one of iron oxidizing bacteria and sulfur oxidizing bacteria in a concentration of 106 microbes/mL, the acid leaching solution having a redox potential of from 550 to 750 mV and 5 g/L or more of iron, the ratio of trivalent iron ions to bivalent iron ions (Fe 3 ...

(PDF) Bacterial Leaching of Metal Sulfides Proceeds by Two ...

Bacterial Leaching of Metal Sulfides Proceeds by Two Indirect Mechanisms via Thiosulfate or via Polysulfides and Sulfur February 1999 Applied and Environmental Microbiology 65(1):319-21

(Bio)chemistry of bacterial leaching

Exclusively iron(III) ions are the oxidizing agents for the dissolution. Thiosulfate is, consequently, degraded in a cyclic process to sulfate, with elemental sulfur being a side product. This explains, why only iron(II) ion-oxidizing bacteria are able to oxidize these metal sulfides.

(Bio)chemistry of bacterial leaching—direct vs. indirect ...

Thiosulfate is, consequently, degraded in a cyclic process to sulfate, with elemental sulfur being a side product. This explains, why only iron(II) ion-oxidizing bacteria are able to oxidize these metal sulfides.