Bioleaching of Copper Slag Material

2017 ◽  
Vol 262 ◽  
pp. 61-64 ◽  
Author(s):  
Axel Schippers
Keyword(s):  
Elemental Sulfur ◽  
Copper Slag ◽  
Economic Feasibility ◽  
Copper Recovery ◽  
Processing Route ◽  
Low Grade ◽  
Acidithiobacillus Thiooxidans ◽  
Biological Assays ◽  
Copper Release ◽  
Mineral Phases

Bioleaching is applied mainly for copper recovery from low-grade sulfide ores via heap leaching. The main copper processing route includes pyrometallurgy and the remaining copper slag from smelting may still contain copper in amounts found in the ore. Here bioleaching of copper slag material with a copper content of about 1 % (grain size < 63 µm) and fayalite (Fe2SiO4) und magnetite (Fe3O4) as main mineral phases was tested in aerobic shake flask experiments with a mixed culture of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium spp..To additionally test for reductive bioleaching, experiments under anaerobic conditions (80% N2, 20% CO2, v/v) with or without addition of elemental sulfur were run. The pH was adjusted to < 3 by addition of sulfuric acid. After the incubation period of more than 50 days at 30°C cell growth was observed in all biological assays. The redox potential was above 800 mV SHE in the aerobic biological assays and dropped to around 500 mV in the chemical control assays as well as in the anaerobic biological and chemical assays. A significant copper bioleaching was observed in the aerobic experiments with 91 % copper release (max. 35 % in the chemical controls). Anaerobic bioleaching experiments did not show a significant copper release, however the release of iron (as iron(II)) and sulfate was much higher than in the abiotic assays and several fold higher than in the classical aerobic bioleaching experiments. Overall the results show that copper bioleaching from slag material is possible, however the economic feasibility needs to be demonstrated.

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

scholarly journals Cost–Benefit Analysis of Municipal Sludge as a Low-Grade Nutrient Source: A Case Study from South Africa

2020 ◽  
Vol 12 (23) ◽  
pp. 9950
Author(s):  
Eyob Habte Tesfamariam ◽  
Zekarias Mihreteab Ogbazghi ◽  
John George Annandale ◽  
Yemane Gebrehiwot
Keyword(s):  
Cost Benefit Analysis ◽  
Arid Zone ◽  
Economic Value ◽  
Cost Benefit ◽  
Economic Feasibility ◽  
Inorganic Fertilizer ◽  
Bench Mark ◽  
Low Grade ◽  
Municipal Sludge ◽  
Humid Zone

Municipal sludge has economic value as a low-grade fertilizer as it consists of appreciable amounts of the macro and micronutrients. When using sludge as fertilizer, the economic aspect should be taken into account. In this study, the following specific objectives were identified: (a) to investigate the economic feasibility of using sludge as a fertilizer; (b) to estimate the maximum economic distance sludge can be transported as a fertilizer; and (c) to test the economic feasibility of selling sludge using commercial inorganic fertilizer as a bench mark. The study showed that for anaerobically digested, paddy dried, municipal sludge consisting of 3% N, 2% P, and 0.3% K the economic feasibility of transporting the sludge was limited to a diameter of 20 km in the arid zone, 28 km in the semi-arid zone, 51 km in the sub humid zone, 66 km in the humid zone, and 75 km in the super-humid zone. Therefore, the economic feasibility of using sludge as a substitute for or complementary to commercial inorganic fertilizer is dictated by the distance between the wastewater care work and the farm, sludge nutrient concentration, agro-ecological zone (rain and temperature), and the real-time commercial inorganic fertilizer price.

scholarly journals Distinct Roles of Acidophiles in Complete Oxidation of High-Sulfur Ferric Leach Product of Zinc Sulfide Concentrate

2020 ◽  
Vol 8 (3) ◽  
pp. 386 ◽  
Author(s):  
Maxim Muravyov ◽  
Anna Panyushkina
Keyword(s):  
Microbial Community ◽  
Zinc Sulfide ◽  
Elemental Sulfur ◽  
Waste Product ◽  
Sulfur Oxidation ◽  
Low Grade ◽  
Sulfide Concentrates ◽  
Sulfide Concentrate ◽  
Elemental Sulfur Oxidation ◽  
Ferric Leaching

A two-step process, which involved ferric leaching with biologically generated solution and subsequent biooxidation with the microbial community, has been previously proposed for the processing of low-grade zinc sulfide concentrates. In this study, we carried out the process of complete biological oxidation of the product of ferric leaching of the zinc concentrate, which contained 9% of sphalerite, 5% of chalcopyrite, and 29.7% of elemental sulfur. After 21 days of biooxidation at 40 °C, sphalerite and chalcopyrite oxidation reached 99 and 69%, respectively, while the level of elemental sulfur oxidation was 97%. The biooxidation residue could be considered a waste product that is inert under aerobic conditions. The results of this study showed that zinc sulfide concentrate processing using a two-step treatment is efficient and promising. The microbial community, which developed during biooxidation, was dominated by Acidithiobacillus caldus, Leptospirillum ferriphilum, Ferroplasma acidiphilum, Sulfobacillus thermotolerans, S. thermosulfidooxidans, and Cuniculiplasma sp. At the same time, F. acidiphilum and A. caldus played crucial roles in the oxidation of sulfide minerals and elemental sulfur, respectively. The addition of L. ferriphilum to A. caldus during biooxidation of the ferric leach product proved to inhibit elemental sulfur oxidation.

scholarly journals Effect of Surface Modification with Different Acids on the Functional Groups of AF 5 Catalyst and Its Catalytic Effect on the Atmospheric Leaching of Enargite

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Jahromi ◽  
Ghahreman
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Elemental Sulfur ◽  
Catalytic Properties ◽  
Copper Recovery ◽  
Pre Treatment ◽  
Sulfur Adsorption

Carbon-based catalysts can assist the oxidative leaching of sulfide minerals. Recently, we presented that AF 5 Lewatit® is among the catalysts with superior enargite oxidation capacity and capability to collect elemental sulfur on its surface. Herein, the effect of acid pre-treatment of the AF 5 catalyst was studied on the AF 5 surface, to further enhance the catalytic properties of AF 5. The AF 5 catalyst was pretreated by hydrochloric acid, nitric acid and sulfuric acid. The results showed that the acid treatment drastically changes the surface properties of AF 5. For instance, the concentration of quinone-like functional groups, which are ascribed to the catalytic properties of AF 5, is 45.4% in the sulfuric acid pre-treatment AF 5 and only 29.8% in the hydrochloric acid-treated AF 5. Based on the C 1s X-ray photoelectron spectroscopy (XPS) results the oxygenated carbon is 30.6% in the sulfuric acid-treated AF 5, 29.2% in the nitric acid-treated AF 5 and 28.3% in the hydrochloric acid-treated AF 5. The nitric acid pre-treated AF 5 resulted in the highest copper recovery during the oxidative enargite leaching process, recovering 98.8% of the copper. The sulfuric acid-treated AF 5 recovered 97.1% of the enargite copper into the leach solution. Among different leaching media and pre-treatment the lowest copper recovery was achieved with the HCl pre-treated AF 5 which was 88.6%. The pre-treatment of AF 5 with acids also had modified its elemental sulfur adsorption capacity, where the sulfur adsorption on AF 5 was increased from 30.9% for the HCl treated AF 5 to 51.1% for the sulfuric acid-treated AF 5.

scholarly journals Rare Earth Elements and Other Critical Metals in Deep Seabed Mineral Deposits: Composition and Implications for Resource Potential

Minerals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 3 ◽  
Author(s):  
Sang-Joon Pak ◽  
Inah Seo ◽  
Kyeong-Yong Lee ◽  
Kiseong Hyeong
Keyword(s):  
Rare Earth ◽  
Deep Sea ◽  
Mineral Resources ◽  
Rare Earth Oxide ◽  
Economic Feasibility ◽  
Mineral Deposits ◽  
Low Grade ◽  
Ion Adsorption ◽  
Critical Metals ◽  
Deep Sea Sediment

The critical metal contents of four types of seabed mineral resources, including a deep-sea sediment deposit, are evaluated as potential rare earth element (REE) resources. The deep-sea resources have relatively low total rare earth oxide (TREO) contents, a narrow range of TREO grades (0.049–0.185%), and show characteristics that are consistent with those of land-based ion adsorption REE deposits. The relative REO distributions of the deep-seabed resources are also consistent with those of ion adsorption REE deposits on land. REEs that are not part of a crystal lattice of host minerals within deep-sea mineral deposits are favorable for mining, as there is no requirement for crushing and/or pulverizing during ore processing. Furthermore, low concentrations of Th and U reduce the risk of adverse environmental impacts. Despite the low TREO grades of the deep-seabed mineral deposits, a significant TREO yield from polymetallic nodules and REE-bearing deep-sea sediments from the Korean tenements has been estimated (1 Mt and 8 Mt, respectively). Compared with land-based REE deposits, deep-sea mineral deposits can be considered as low-grade mineral deposits with a large tonnage. The REEs and critical metals from deep-sea mineral deposits are important by-products and co-products of the main commodities (e.g., Co and Ni), and may increase the economic feasibility of their extraction.

Copper Recovery by Bioleaching of Chalcopyrite: A Microcalorimetric Approach for the Fast Determination of Bioleaching Activity

2013 ◽  
Vol 825 ◽  
pp. 322-325
Author(s):  
Beate Krok ◽  
Axel Schippers ◽  
Wolfgang Sand
Keyword(s):  
Enrichment Culture ◽  
Sulfide Oxidation ◽  
Exothermic Reaction ◽  
Metal Sulfide ◽  
Copper Recovery ◽  
Heat Output ◽  
Low Grade ◽  
Non Invasive ◽  
Pure Cultures ◽  
Invasive Method

Low grade copper ores containing chalcopyrite are increasingly used for copper recovery via biomining. Since metal sulfide oxidation is an exothememic process, bioleaching activity can be measured due to the heat output by microcalorimetry, which is a non-destructive and non-invasive method. The bioleaching activity of pure cultures ofSulfolobus metallicus,Metallosphaera hakonensisand a moderate thermophilic enrichment culture on high grade chalcopyrite was evaluated. Chalcopyrite leaching by microorganisms showed a higher copper recovery than sterile controls. Chemical chalcopyrite leaching by acid produced heat due to the exothermic reaction, the heat output was increased while metal sulfide oxidation by microorganisms.

Bioleaching of Low-Grade Copper Sulfide Ore Using a Colum Reactor

2009 ◽  
Vol 71-73 ◽  
pp. 409-412
Author(s):  
Wen Qing Qin ◽  
Yan Sheng Zhang ◽  
Shi Jie Zhen ◽  
Jun Wang ◽  
Jian Wen Zhang ◽  
...  
Keyword(s):  
Iron Concentration ◽  
Mixed Cultures ◽  
Copper Recovery ◽  
Low Grade ◽  
Leaching Rate ◽  
Ministry Of Education ◽  
Copper Ore ◽  
Copper Leaching ◽  
Pure Cultures ◽  
Mixed Bacteria

The effects of several variables on the column bioleaching of copper sulphide ore have been investigated. The copper ore contained chalcopyrite as the main sulfide minerals and bornite and chalcocite as the minor minerals. The experiment was carried out using bench-scale column leach reactors designed in Key Lab of Biometallurgy of Ministry of Education, which were inoculated with the pure mesophile bacteria (Acidithiobacillus ferrooxidans) and thermophile bacteria (Sulfobacillus), respectively, and the mixed bacteria which contain both iron- and sulfur-oxidizing bacteria. The results show that the mixed cultures were more efficient than the pure cultures alone and the maximum copper recovery 53.64% was achieved using the mixed cultures after 85 days. The leaching rate of chalcopyrite tended to increase with the increased dissolved ferric iron concentration. The effect of particle size on the rate of the copper leaching was also investigated, and it was shown that the copper bioleaching rate decreases as the amount of fines increase, which limits the permeability, thus decreases leaching rate. Jarosite and elemental sulphur formed in the column were characterized by the X-ray and EDS.

A Study of the Optimal Model of the Flotation Kinetics of Copper Slag from Copper Mine BOR

2014 ◽  
Vol 59 (3) ◽  
pp. 821-834 ◽  
Author(s):  
Rodoljub D. Stanojlović ◽  
Jovica M. Sokolović
Keyword(s):  
Pure Copper ◽  
Copper Slag ◽  
Copper Recovery ◽  
Optimal Model ◽  
Flotation Kinetics ◽  
Kinetics Parameters ◽  
Flotation Tailings ◽  
Copper Mine ◽  
Flotation Cell ◽  
Kinetics Of

Abstract In this study the effect of mixtures of copper slag and flotation tailings from copper mine Bor, Serbia on the flotation results of copper recovery and flotation kinetics parameters in a batch flotation cell has been investigated. By simultaneous adding old flotation tailings in the ball mill at the rate of 9%, it is possible to increase copper recovery for about 20%. These results are compared with obtained copper recovery of pure copper slag. The results of batch flotation test were fitted by MatLab software for modeling the first-order flotation kinetics in order to determine kinetics parameters and define an optimal model of the flotation kinetics. Six kinetic models are tested on the batch flotation copper recovery against flotation time. All models showed good correlation, however the modified Kelsall model provided the best fit.

scholarly journals Copper Recovery from Silicate-Containing Low-Grade Copper Ore Using Flotation Followed by High-Pressure Oxidative Leaching

2017 ◽  
Vol 64 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Baisui HAN ◽  
Batnasan ALTANSUKH ◽  
Kazutoshi HAGA ◽  
Yasushi TAKASAKI ◽  
Atsushi SHIBAYAMA
Keyword(s):  
High Pressure ◽  
Copper Recovery ◽  
Low Grade ◽  
Copper Ore ◽  
Oxidative Leaching

Bioleaching of Low-Grade Chalcopyrite Ore by the Thermophilic Archaean Acidianus brierleyi

2017 ◽  
Vol 262 ◽  
pp. 237-241 ◽  
Author(s):  
Norizoh Saitoh ◽  
Toshiyuki Nomura ◽  
Yasuhiro Konishi
Keyword(s):  
Environmentally Friendly ◽  
Copper Recovery ◽  
Copper Extraction ◽  
Low Grade ◽  
Column Reactor ◽  
Stirred Reactor ◽  
Acidianus Brierleyi ◽  
Environmentally Friendly Process ◽  
Chalcopyrite Ore

The thermophilic archaean, Acidianus brierleyi, was examined for its feasibility to bioleach copper from a low-grade chalcopyrite ore (1.15 % copper, 20.4 % iron and 2.63 wt% sulfur) at 65°C and pH 1.8-2.5. The chalcopyrite leaching was markedly accelerated in the presence of A. brierleyi, and an extremely high 80% leaching of copper in the low-grade ore (25-38 μm particles) was achieved in 14 days in a batch stirred reactor. By comparison, the leaching of iron was very slow and only a slight 5 % iron was leached in 14 days in the presence or absence of A. brierleyi. In other words, A. brierleyi selectively leached chalcopyrite while magnetite leaching by A. brierleyi was negligible. Moreover, bioleaching of the low-grade ore (53-75 μm particles) yielded 55% copper recovery after 20 days of operation in a column reactor. The good results for the copper bioleaching in the column reactor are very similar to those in the stirred reactor. These results lead to the conclusion that the thermophile bioleaching with A. brierleyi is attractive as an economical and environmentally friendly process for good copper extraction from low-grade chalcopyrite ore.

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