References  Abraitis, P. Many researchers Konishi et al. When the very reactive sulfide radical from H2O2 comes in contact with the highly reactive sulfide mineral, elemental sulfur is formed.
Hydrometallurgy, 27, - Abstract Waste materials from metal mining, such as mineral tailings, often contain significant amounts of potentially valuable metals particularly where, as in many historic operations, the efficiency of flotation technologies used to concentrate target minerals was not as good as those currently available.
The future of biomining is challenging, as it offers advantages of operational simplicity, low capital and operational cost and shorter construction which no other alternative process can provide.
Metallurgical and Minig Industry, 2 3 Schultze, L. Their results showed that the leaching of metals from chalcopyrite occurs according to the following reactions: Complex sulfide ores are in many cases difficult to treat with conventional mineral processing method and the concentrate produced is often not clean enough.
Muniz - Ribadeneira and Gomberg also reported that 0. He suggested that NaCl act on the elemental sulphur layer and also on the solubility of copper complexes in the reaction system with aim to improving the copper extraction from the sulfide mineral in a relatively short time with low operation cost, taking into consideration the influence of a cationic surfactant.
Carbon dioxide is obtained from ambient air, nutrients are added to the leach liquor and retention time is about 30 days. Copper recoveries were found to be significantly increased as the concentration of sulfuric acid and hydrogen peroxide increased.
Based on this, several works in terms of theories and hypothesis have been proposed.
The off-line system used allowed the copper present in PLS to be precipitated selectively without the need to adjust the pH of the PLS, though small amounts of silver present in PLS from one of the tailings samples co-precipitated with copper sulfide.
According to Abraitis et al. Bioleaching CWD Innovation, p. Then hydrogen sulfide is oxidized by ferric ion to cupric ions and elemental sulfur. Science Engineering, 1, 4 - Hydrometallurgy consists of crushing, leaching non-oxidation leaching, atmospheric leaching and pressure leachingsolvent extraction and electrowinning and can be effectively applied for oxidized ores as well as for sulfide ores with chalcopyrite as a predominant copper mineral.
The thermo-tolerant acidophiles Acidithiobacillus caldus and Sulfobacillus thermosulfidooxidans emerged as the dominant bacteria present in both tailings leachates under these conditions.
Agitation was found to have a negative effect on cupric ion, the fact that cupric complexes are formed during the leaching process where the cupric ion is considered as a string oxidant.
Patent 5, - The most important one is the conventional - pyrometallurgy method comprised numerous types of shaft and flash technologies, which consists of crushing, grinding, flotation, smelting refining and electro-refining. Sulfide oxidation chemistry is similar to the CESL process.
Geologica Acta 7 3 The results of this study have shown that sulfuric acid leaching in the presence of hydrogen peroxide is an effective route for copper and zinc recovery from Nigerian complex sulfide ore.
These authors did not address some kinetic parameters such as activation energy Eareaction order, Arrhenius constant etc. In general, experiences have been shared based on various researches on hydrometallurgical process and now we find that many deposit around the world that have previously not been regarded as suitable for economic exploitation are being re-considered and this will hopefully lead to the valuable economic regeneration of other mineralogical areas.
Hydrometallurgy of copper, Book 1, Vol.
Leaching of chalcopyrite concentrate is complete within 10 days Dresher, Microbial Leaching Studies on Chalcopyrite Biohydrometallurgy treatments have been practiced extensively for metal recovery from low-grade sulfide - bearing materials Maouf, They consider that the limiting step of the chalcopyrite dissolution with ferric ion is the transport of electrons needed for the cathode reduction reaction through an insulating layer of elemental sulfur.
Therefore, 26 From the latter equation, the kinetic parameters of the reaction were calculated: The basis of hydrometallurgy is justified not only by economical, but also ecological reasons. Recent studies by Bryn et al. In recent times, attention has been drawn to low-grade complex sulfide ores due to the decline in the world deposits of high - grade ores.
The test shows evidence that the electro-leaching process makes possible the production of chlorate ion that dissolves the copper sulphides releasing copper ion to solution, which are simultaneously reduced in the cathode surface.
Their approach enabled to analyze chalcopyrite dissolution kinetic according to the shrinking core model and to propose a mechanism for the control of the dissolution rate. According to this model, the rate of H2S decreases with increasing chalcopyrite surface potential from 0.
The thiobacillus ferrooxidans which is responsible for metal dissolution derives the necessary energy for its life process from oxidation of ferrous iron Silverman, and reduced valence inorganic sulfur compounds Silver and Torma, and thus utilizes carbon dioxide for growth when cultured on metal plates.
The Free Encylopaedia, Copper, http: According to Nowaczyk et al.The most successful copper heap leaching operations have been those processing copper oxides and secondary copper sulphides ().Chalcocite (Cu 2 S) is the main copper sulphide mineral mined at bioleaching operations.
Some of the chalcocite heap operations began as oxide (chemical) leach operations and were converted to bioleach (oxidative) operations by heap aeration and/or inoculation.
New approaches for extracting and recovering metals from mine tailings. Chalcopyrite ores are usually processed by means of hydrometallurgical or pyrometallurgical processes, but due to environmental aspects and the possibility of increased exploitation of mixed and lower grade ores and relatively small isolated deposits, there has been a worldwide upsurge of interest in the hydrometallurgical processes of this ore as compared to pyrometallurgy.Download