Extraction of Mn from Black Copper Using Iron Oxides from Tailings and Fe2+ as Reducing Agents in Acid Medium

Exotic type deposits include several species of minerals, such as atacamite, chrysocolla, copper pitch, and copper wad. Among these, copper pitch and copper wad have considerable concentrations of manganese. However, their non-crystalline and amorphous structure makes it challenging to recover the elements of interest (like Cu or Mn) by conventional hydrometallurgical methods. For this reason, black copper ores are generally not incorporated into the extraction circuits or left unprocessed, whether in stock, leach pads, or waste. Therefore, to dilute MnO2, the use of reducing agents is essential. In the present research, agitated leaching was performed to dissolve Mn of black copper in an acidic medium, comparing the use of ferrous ions and tailings as reducing agents. Two samples of black copper were studied, of high and low grade of Mn, respectively, the latter with a high content of clays. The effect on the reducing agent/black copper ratio and the concentration of sulfuric acid in the system were evaluated. Better results in removing Mn were achieved using the highest-grade black copper sample when working with ferrous ions at a ratio of Fe2+/black copper of 2/1 and 1 mol/L of sulfuric acid. Besides, the low-grade sample induced a significant consumption of H2SO4 due to the high presence of gangue and clays.

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Preliminary Studies on Acid Leaching of Finely-Ground Malaysian Low Grade Manganese Ore (LGMO)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.840.364 ◽

2016 ◽

Vol 840 ◽

pp. 364-368 ◽

Cited By ~ 1

Author(s):

Mohd Fasyraf Hafizi Mohd Rozali ◽

Nurulfazielah Nasir ◽

Suhaina Ismail ◽

Norazharuddin Shah Abdullah

Keyword(s):

Sulfuric Acid ◽

Fine Particle ◽

Acid Leaching ◽

Reducing Agents ◽

Low Grade ◽

Manganese Ore ◽

Particle Sizes ◽

Leaching Process

Ore samples, believed to be low grade manganese ore were characterized using XRD, XRF and SEM, before being ground further into very fine particle sizes going through a preliminary leaching process. Sulfuric acid was chosen as the leachant, and leaching was done without any presence of reducing agents.

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Reducing-Effect of Chloride for the Dissolution of Black Copper

Metals ◽

10.3390/met10010123 ◽

2020 ◽

Vol 10 (1) ◽

pp. 123 ◽

Cited By ~ 1

Author(s):

David Torres ◽

Kevin Pérez ◽

Emilio Trigueros ◽

Ricardo I. Jeldres ◽

Eleazar Salinas-Rodríguez ◽

...

Keyword(s):

Standard Condition ◽

Amorphous Structure ◽

Reducing Agents ◽

Reducing Agent ◽

Copper Mineral ◽

Conventional Methods ◽

Pre Treatment ◽

High Concentrations ◽

Copper Ores

Oxidized black copper ores are known for their difficulty in dissolving their components of interest through conventional methods. This is due to its non-crystalline and amorphous structure. Among these minerals, copper pitch and copper wad are of great interest because of their considerable concentrations of copper and manganese. Currently, these minerals are not incorporated into the extraction circuits or left untreated, whether in stock, leach pads, or waste. For the recovery of its main elements of interest (Cu and Mn), it is necessary to use reducing agents that dissolve the present MnO2, while allowing the recovery of Cu. In this research, the results for the dissolution of Mn and Cu from a black copper mineral are exposed, evaluating the reducing effect of NaCl for MnO2 through pre-treatment of agglomerate and curing, and subsequently leaching in standard condition with the use of a reducing agent (Fe2+). High concentrations of chloride in the agglomerate process and prolonged curing times would favor the reduction of MnO2, increasing the dissolution of Mn, while the addition of NaCl did not benefit Cu extractions. Under standard conditions, low Mn extractions were obtained, while in an acid-reducing medium, a significant dissolution of MnO2 was achieved, which supports the removal of Cu.

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Silver catalyzed bioleaching of low-grade copper ores. Part III: Column reactors

Hydrometallurgy ◽

10.1016/j.hydromet.2007.04.003 ◽

2007 ◽

Vol 88 (1-4) ◽

pp. 35-51 ◽

Cited By ~ 19

Author(s):

J.A. Muñoz ◽

D.B. Dreisinger ◽

W.C. Cooper ◽

S.K. Young

Keyword(s):

Low Grade ◽

Copper Ores

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Reductive Mobilization of Iron from Intact Ferritin: Mechanisms and Physiological Implication

Pharmaceuticals ◽

10.3390/ph11040120 ◽

2018 ◽

Vol 11 (4) ◽

pp. 120 ◽

Cited By ~ 16

Author(s):

Fadi Bou-Abdallah ◽

John Paliakkara ◽

Galina Melman ◽

Artem Melman

Keyword(s):

Protein Structures ◽

Reducing Agents ◽

Iron Core ◽

Ferrous Ions ◽

Major Pathway ◽

Iron Mobilization ◽

Iron Mineral ◽

Mineral Core

Ferritins are highly conserved supramolecular protein nanostructures composed of two different subunit types, H (heavy) and L (light). The two subunits co-assemble into a 24-subunit heteropolymer, with tissue specific distributions, to form shell-like protein structures within which thousands of iron atoms are stored as a soluble inorganic ferric iron core. In-vitro (or in cell free systems), the mechanisms of iron(II) oxidation and formation of the mineral core have been extensively investigated, although it is still unclear how iron is loaded into the protein in-vivo. In contrast, there is a wide spread belief that the major pathway of iron mobilization from ferritin involves a lysosomal proteolytic degradation of ferritin, and the dissolution of the iron mineral core. However, it is still unclear whether other auxiliary iron mobilization mechanisms, involving physiological reducing agents and/or cellular reductases, contribute to the release of iron from ferritin. In vitro iron mobilization from ferritin can be achieved using different reducing agents, capable of easily reducing the ferritin iron core, to produce soluble ferrous ions that are subsequently chelated by strong iron(II)-chelating agents. Here, we review our current understanding of iron mobilization from ferritin by various reducing agents, and report on recent results from our laboratory, in support of a mechanism that involves a one-electron transfer through the protein shell to the iron mineral core. The physiological significance of the iron reductive mobilization from ferritin by the non-enzymatic FMN/NAD(P)H system is also discussed.

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Uranium Bioleaching from Low Grade Ore

Materials Science Forum ◽

10.4028/www.scientific.net/msf.989.559 ◽

2020 ◽

Vol 989 ◽

pp. 559-563

Author(s):

Ashimkhan T. Kanayev ◽

Khussain Valiyev ◽

Aleksandr Bulaev

Keyword(s):

Sulfuric Acid ◽

Acid Mine Drainage ◽

Mine Drainage ◽

Sulfuric Acid Concentration ◽

Acid Leaching ◽

Leach Solution ◽

Low Grade ◽

Bacterial Cells ◽

Acid Mine

The goal of the present work was to perform bioleaching of uranium from low grade ore from Vostok deposit (Republic of Kazakhstan), which was previously subjected to long-term acid leaching. The ore initially contained from 0.15 to 0.20% of uranium in the form of uraninite, but ore samples used in the study contained about 0.05% of uranium, as it was exhausted during acid leaching, and uranium was partially leached. Representative samples of ore were processed in 1 m columns, leach solutions containing 5, 10, 20 g/L of sulfuric acid and bacterial cells (about 104) were percolated through the ore. Leaching was performed at ambient temperature for 70 days. In one of the percolators, the leaching was performed with leaching solution containing 10 g/L of H2SO4, cells of A. ferrooxidans, and 0.5 g/L of formaldehyde. Leaching with the solution containing 5, 10, and 20 g/L of sulfuric acid made it possible to extract 50, 53, and 58% of uranium. Addition of formaldehyde in leach solution led to the decrease in uranium extraction extent down to 37%. Thus, the results of the present work demonstrated that uranium ore exhausted during long-term acid leaching may be successfully subjected to bioleaching, that allows extracting residual quantities of uranium. Leaching rate of uranium from exhausted ore depended on both sulfuric acid concentration and microbial activity of bacteria isolated from acid mine drainage, formed on uranium deposit. In the same time, acid mine drainage may be used as a source of inoculate, to start bioleaching process.

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The Effect of Different Oxidants on Extraction of Uranium from Low Grade Ore

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.299.1104 ◽

2020 ◽

Vol 299 ◽

pp. 1104-1108

Author(s):

Ashimkhan T. Kanayev ◽

Khussain Valiyev ◽

Aleksandr Bulaev

Keyword(s):

Sulfuric Acid ◽

Potassium Permanganate ◽

Ferric Sulfate ◽

Low Grade ◽

Acid Solutions ◽

Uranium Recovery ◽

Ammonium Persulphate ◽

Uranium Extraction ◽

Increase Rate ◽

Sulfuric Acid Solutions

The effect of different oxidants on extraction of uranium from low grade ore was studied. Leaching was performed using sulfuric acid solutions at a concentration of 10 to 30%. Ferric sulfate Fe2(SO4)3, ammonium persulphate (NH4)2S2O8, and potassium permanganate KMnO4 at different concentrations were used as oxidants in different variants of the experiment. In addition, solutions collected at Vostok deposit containing 6.86 g/L Fe3+ and 106 cells/mL of the bacteria Acidithiobacillusferrooxidans were used for leaching. The rate of uranium extraction with sulfuric acid solutions without oxidants was low and did not exceed 19.4%. Addition of oxidants made it possible to increase rate of uranium extraction. In the presence of ferric sulfate, ammonium persulphate, and potassium permanganate rates of uranium extraction were up to 68, 95.2, and 69.6%, respectively. The rate of uranium leaching in the experiments with the AMD sample was high and reached about 95%. Therefore, it can be concluded that using not only oxidizing agents, but AMD, which are formed during the natural oxidation of sulfide minerals contained in the ore of the deposit, can significantly increase the rate of uranium recovery.

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A Novel Technology for Separating Copper, Lead and Zinc in Flotation Concentrate by Oxidizing Roasting and Leaching

Processes ◽

10.3390/pr7060376 ◽

2019 ◽

Vol 7 (6) ◽

pp. 376 ◽

Cited By ~ 2

Author(s):

Qian Zhang ◽

Qicheng Feng ◽

Shuming Wen ◽

Chuanfa Cui ◽

Junbo Liu

Keyword(s):

Sulfuric Acid ◽

Acid Leaching ◽

Mining Area ◽

Low Grade ◽

Flotation Concentrate ◽

Copper And Zinc ◽

Lead And Zinc ◽

Electron Microscopy Analysis ◽

Leaching Parameters ◽

Copper Lead

In this work, oxidizing roasting was combined with leaching to separate copper, lead, and zinc from a concentrate obtained by bulk flotation of a low-grade ore sourced from the Jiama mining area of Tibet. The flotation concentrate contained 7.79% Cu, 22.00% Pb, 4.81% Zn, 8.24% S, and 12.15% CaO; copper sulfide accounted for 76.97% of the copper, lead sulfide for 25.55% of the lead, and zinc sulfide for 67.66% of the zinc. After oxidizing roasting of the flotation concentrate, the S content in the roasting slag decreased to 0.22%, indicating that most sulfide in the concentrate was transformed to oxide, which was beneficial to leaching. The calcine was subjected to sulfuric acid leaching for separation of copper, lead, and zinc; i.e., copper and zinc were leached, and lead was retained in the residue. The optimum parameters of the leaching process were: a leaching temperature of 55 °C; sulfuric acid added at 828 kg/t calcine; a liquid:solid ratio of 3:1; and a leaching time of 1.5 h. Under these conditions, the extents of leaching of copper and zinc were 87.43% and 64.38%, respectively. Copper and zinc in the leaching solution could be further separated by electrowinning. The effects of leaching parameters on the extents of leaching of copper and zinc were further revealed by X-ray diffraction and scanning electron microscopy analysis.

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Reduction-Roast Leaching of Low-Grade Pyrolusite Using Bagasse as a Reducing Agent

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.699.28 ◽

2013 ◽

Vol 699 ◽

pp. 28-33 ◽

Cited By ~ 3

Author(s):

Yun Fei Long ◽

Jing Su ◽

Xian Jia Ye ◽

Hai Feng Su ◽

Yan Xuan Wen

Keyword(s):

Sulfuric Acid ◽

Acid Concentration ◽

Sulfuric Acid Concentration ◽

Weight Ratio ◽

Reducing Agent ◽

Manganese Sulfate ◽

Low Grade ◽

Manganese Ore ◽

Optimal Conditions ◽

Roasting Temperature

Bagasse, a fibrous residue from sugarcane juice extraction, was used as a reducing agent to roast low-grade pyrolusite in N2. The roasted ore was further leached using sulfuric acid, to convert manganese oxide in the ore to manganese sulfate. The effects of weight ratio of bagasse to manganese ore, roasting temperature, roasting time, leaching temperature, leaching time, stirring speed and sulfuric acid concentration on the leaching recovery of manganese were investigated. Optimal conditions were determined to be a bagasse to manganese ore weight ratio of 0.8:10, roasting temperature of 500°C for 40 min, leaching stirring speed of 100 rpm, sulfuric acid concentration of 3 mol•L-1 and leaching temperature of 50°C for 40 min. The leaching recovery rate of manganese was up to 97.8% at the optimal conditions.

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