scholarly journals The Effects of Sulphuric Acid and Sodium Chloride Agglomeration and Curing on Chalcopyrite Leaching

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 873
Author(s):  
Víctor Quezada ◽  
Antoni Roca ◽  
Oscar Benavente ◽  
Montserrat Cruells ◽  
Evelyn Melo
Keyword(s):  
Sodium Chloride ◽  
Sulphuric Acid ◽  
Copper Extraction ◽  
Curing Time ◽  
X Ray Diffraction ◽  
Sulphide Ores ◽  
Reflected Light ◽  
Copper Leaching ◽  
Kinetics Of ◽  
Leaching Efficiency

An option to improve the leaching efficiency of chalcopyrite is pretreatment prior to leaching. Pretreatment variables, such as the curing time and the addition of chloride, can increase the kinetics of copper extraction, particularly for sulphide ores. However, there has been little research on the topic. The reactions that govern this phenomenon have not been clearly identified. In this study, the effects of sulphuric acid and sodium chloride agglomeration and curing on chalcopyrite leaching were evaluated at various temperatures: 25, 50, 70, and 90 °C. The pretreated ore and leach residues were characterised by X-ray diffraction, scanning electron microscopy, and reflected light microscopy. Under the conditions of 15 kg/t of H2SO4, 25 kg/t of NaCl, and 15 days of curing time (as pretreatment), the following products were identified: CuSO4, NaFe3(SO4)2(OH)6, Cu2Cl(OH), and S0. Increasing the curing time and leaching temperature increased copper leaching. The copper extraction was 94% when leaching at 90 °C after pretreatment with 50 g/L of Cl- and 0.2 M of H2SO4. Elemental sulphur, jarosite, and copper polysulphide (CuS2) were detected in the leaching residues.

scholarly journals Pretreatment to Leaching for a Primary Copper Sulphide Ore in Chloride Media

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1260
Author(s):  
Víctor Quezada ◽  
Antoni Roca ◽  
Oscar Benavente ◽  
Montserrat Cruells ◽  
Evelyn Melo ◽  
...  
Keyword(s):  
Copper Extraction ◽  
Copper Sulphide ◽  
Curing Time ◽  
X Ray Diffraction ◽  
Initial Sample ◽  
Mining Company ◽  
Sulphide Ore ◽  
Sulphide Ores ◽  
Reflected Light ◽  
Mineral Sample

The dissolution of copper sulphide ores continues to be a challenge for the copper industry. Several media and leaching alternatives have been proposed to improve the dissolution of these minerals, especially for the leaching of chalcopyrite. Among the alternatives, pretreatment prior to leaching was proposed as an option that increases the dissolution of copper from sulphide ores. In this study, a mineral sample from a copper mining company was used. The copper grade of the sample was 0.79%, and its main contributor was chalcopyrite (84%). The effect of curing time (as pretreatment) in a chloride media on copper sulphide ore was evaluated at various temperatures: 25, 50, 70 and 90 °C. The pretreated sample and leaching residues were characterized by X-ray diffraction, scanning electron microscopy, and reflected light microscopy. Pretreatment products such as CuSO4, NaFe3(SO4)2(OH)6, and S0 were identified although with difficulty, due to the low presence of chalcopyrite in the initial sample (1.99%). Under the conditions of 15 kg/t of H2SO4, 25 kg/t of NaCl, and 15 days of curing time, a copper extraction of 93.1% was obtained at 90 °C with 50 g/L of Cl− and 0.2 M of H2SO4.

scholarly journals Leaching of Chalcopyrite under Bacteria–Mineral Contact/Noncontact Leaching Model

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 230
Author(s):  
Pengcheng Ma ◽  
Hongying Yang ◽  
Zuochun Luan ◽  
Qifei Sun ◽  
Auwalu Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Passivation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Process ◽  
Copper Leaching ◽  
Hydrolysis Of ◽  
Leaching Efficiency ◽  
Leaching Models ◽  
Scanning Electron

Bacteria–mineral contact and noncontact leaching models coexist in the bioleaching process. In the present paper, dialysis bags were used to study the bioleaching process by separating the bacteria from the mineral, and the reasons for chalcopyrite surface passivation were discussed. The results show that the copper leaching efficiency of the bacteria–mineral contact model was higher than that of the bacteria–mineral noncontact model. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) were used to discover that the leaching process led to the formation of a sulfur film to inhibit the diffusion of reactive ions. In addition, the deposited jarosite on chalcopyrite surface was crystallized by the hydrolysis of the excess Fe3+ ions. The depositions passivated the chalcopyrite leaching process. The crystallized jarosite in the bacteria EPS layer belonged to bacteria–mineral contact leaching system, while that in the sulfur films belonged to the bacteria–mineral noncontact system.

Column Bioleaching of Low Grade Copper Sulfide Ore at Extreme Conditions for Most Mineral Processing Bacteria

2013 ◽  
Vol 825 ◽  
pp. 318-321 ◽  
Author(s):  
Gang Zou ◽  
Zeng Ling Wu ◽  
Xiao Kang Lai ◽  
Lai Chang Zou ◽  
Ren Man Ruan ◽  
...  
Keyword(s):  
Iron Concentration ◽  
Heap Leaching ◽  
Operating Conditions ◽  
Industrial Plant ◽  
Copper Extraction ◽  
Low Grade ◽  
Extreme Conditions ◽  
Leaching Rate ◽  
Copper Leaching ◽  
Leaching Efficiency

This study is prompted by the high leaching efficiency of Zijinshan copper bio-heap leaching industrial plant. Bioleaching columns with 100 mm diameter and 1 m height were used to investigate copper bioleaching at different operating conditions. Elevated temperature, high total iron concentration and high acidity significantly increased copper leaching rate as determined by solution and residue assays. At 60 °C with 50 g/L iron (initial Fe3+/Fe2+ gram ratio 2.5), pH 1.0 and no aeration, copper extraction was achieved 90% after 60 days. However, at 30°C, 5 g/L total Fe, pH 1.5 and no aeration, copper extraction reached 80% and 85% after 90 and 200 days, respectively. Real-time PCR assay showed that only 105 cells/ml and 2×105 cells/g are in solution and on the ore surface at the condition of 60 °C 50 g/L iron and pH 1.0, respectively. In addition, a similar leaching rate was observed in the tests with and without inoculation. The column without inoculation was directly irrigated with acid mine drainage (AMD). Our results indicate high copper leaching efficiency at extreme conditions for mineral oxidizing bacteria. Inoculation and aeration are not necessary in Zijinshan copper mine bio-heap leaching process.

scholarly journals Sequential leaching of copper from mill tailings with aqueous solutions of hydrochloric acid and sodium hypochlorite

2021 ◽  
Vol 340 ◽  
pp. 01029
Author(s):  
Leilya Syzdykova ◽  
Nargiza Nurtazina ◽  
Aidana Erdenbekova
Keyword(s):  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Sodium Hypochlorite ◽  
Maximum Degree ◽  
Room Temperature ◽  
Copper Extraction ◽  
Sequential Leaching ◽  
Mill Tailings ◽  
Copper Leaching ◽  
Kinetics Of

This work presents an investigation of kinetics of copper leaching from mill tailings with hydrochloric acid and sodium hypochlorite at room temperature in filtration mode. The concentration of hydrochloric acid and sodium hypochlorite varied from 0.05 to 0.5 M and 0.025 to 0.1 M respectively. When the samples were leached in the sequence of five-hour leaching with solutions of hydrochloric acid, and then six-hour with sodium hypochlorite, the maximum degree of copper extraction into the solution was 32.62 %. And in case of leaching samples in the inverse direction, with a solution of sodium hypochlorite for two hours, and then with hydrochloric acid for seven hours, 87.10 % of copper was extracted, which is 2.67 times more than in the previous case. It has been shown that the sequence of using reagents in leaching has a significant impact on the efficiency of copper extraction from the tailings.

scholarly journals Kinetics of Cu 2+ Copper Sorption from Water Systems by Modified Aluminum Silicates

2012 ◽  
pp. 99-110
Author(s):  
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Sodium Chloride ◽  
Sodium Hydroxide ◽  
Water Systems ◽  
Copper Extraction ◽  
Natural Sorbents ◽  
Kinetics Of ◽  
Modified Sorbents ◽  
Copper Sorption

Regent methods of natural sorbents modification on the basis of opal/ cristobalite rocks have been developed. Optimal reagents for the natural sorbents modification are solutions of sodium hydroxide and sodium chloride. Kinetics of Cu2+ copper extraction from water systems with the modified sorbents has been studied in different conditions: depending on the velocity of stirring, sorbent particle size, and the extracted metal concentration. The conducted research enables to recommend the modified sorbents on the basis of opal/cristobalite rocks for extraction of heavy metals from water systems.

scholarly journals Final flotation waste kinetics of sintering at different heating regimes

2016 ◽  
Vol 48 (2) ◽  
pp. 197-208
Author(s):  
Mira Cocic ◽  
Mihovil Logar ◽  
Branko Matovic ◽  
Snezana Devic ◽  
Tatjana Husovic-Volkov ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Fluorescence Analysis ◽  
Ceramic Materials ◽  
Copper Extraction ◽  
Heating Regime ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pyrometallurgical Processing ◽  
Kinetics Of

In the copper extraction, especially during the process of flotation enrichment and the pyrometallurgical processing, the waste materials that represent huge polluters of environment are being generated. In order to examine the application of Final flotation waste (FFW) in the manufacturing of new materials from the glass-ceramic group phase and mineral composition were examined as well as thermal properties. FFW kinetics of sintering has been tested at different dyamics (1?C/min, 29?C/min and 43?C/min), in order to find the optimum conditions for sintering with a minimum amount of energy and time consumption. The samples were examined using: X-ray diffraction, X-ray fluorescence analysis, SEM (Scanning Electron Microscopy) and thermal microscopy. The best results for the production of glass ceramic materials were obtained during the sintering at heating regime of 29?C/min.

Removal of Metal Impurities from the Spent Hydroprocessing Catalyst and Acid Leaching Kinetics of Aluminum

2020 ◽  
Vol 993 ◽  
pp. 1438-1444
Author(s):  
Zi Jie Yang ◽  
Hui Yu ◽  
Li Wen Ma ◽  
Xiao Li Xi ◽  
Yun He Zhang
Keyword(s):  
Acid Leaching ◽  
X Ray Diffraction ◽  
Leaching Behavior ◽  
X Ray ◽  
Metal Impurities ◽  
Leaching Residue ◽  
Efficient Recovery ◽  
Leaching Reaction ◽  
Kinetics Of ◽  
Leaching Efficiency

The impurity metal of Al in spent hydroprocessing catalyst (Mo-Ni/Al2O3) was removed by HCl, and the metals of Mo and Ni were preliminarily enriched. The results show that the leaching efficiency of Al was 88.62%, and the leaching efficiency of Mo and Ni were 16.32% and 28.74%, respectively. The results were achieved under optimal leaching conditions: the particle size was 150 μm, the concentration of HCl was 4 mol/L, the leaching temperature was 90 °C, and the leaching time was 120 min. The kinetics of the leaching behavior of Al showed that the acid leaching reaction of Al was in accorded with the equation 1-2/3X-(1-X) 2/3=K2t, R2=0.97734, which was controlled by internal diffusion. X-ray diffraction analysis of the leaching residue revealed the existence of residual metals Mo(MoO3, MoO2(ClO4)2)and Ni(NiS). The separation of Al from Mo and Ni has been preliminarily realized, which is conducive to further efficient recovery of Mo and Ni.

Kinetics of ultrasound-assisted silver leaching from sintering dust using thiourea

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Jun Chang ◽  
Erdong Zhang ◽  
Changjiang Yang ◽  
Junwen Zhou ◽  
Jinhui Peng ◽  
...  
Keyword(s):  
Noble Metals ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Water Leaching ◽  
X Ray ◽  
Diffusion Controlled ◽  
Order Kinetic Model ◽  
Thiourea Concentration ◽  
Kinetics Of ◽  
Leaching Efficiency

AbstractIn the process of steel manufacture, up to tens of millions of tons of sintering dusts are produced annually in China, which contain noble metals such as Ag. Therefore, the recovery of Ag from sintering dust could be a potential economic and environmental activity. The present work attempts to use ultrasound for leaching silver from the water-leaching residue of sintering dust (WLR-SD) by acidic thiourea at atmospheric pressure. The effects of particle size, leaching temperature, and thiourea concentration were assessed on the leaching efficiency. Mineralogical changes of the WLR-SD were estimated using X-ray fluorescence, X-ray diffraction, and scanning electron microscope. The results have shown that under the conditions used, up to 94% silver could be leached. The leaching kinetics was estimated to follow the first-order kinetic model, and the activation energy was estimated to be 20.7 kJ/mol, confirming an internal diffusion-controlled leaching process. The order of the reaction with respect to the thiourea concentration was estimated to be 0.68.

scholarly journals Tamuraite, Ir5Fe10S16, a New Species of Platinum-Group Mineral from the Sisim Placer Zone, Eastern Sayans, Russia

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 545
Author(s):  
Andrei Y. Barkov ◽  
Nadezhda D. Tolstykh ◽  
Robert F. Martin ◽  
Andrew M. McDonald
Keyword(s):  
National Laboratory ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
Cell Parameters ◽  
Reflected Light ◽  
Platinum Group Minerals ◽  
Platinum Group ◽  
Probable Space ◽  
Layered Complex ◽  
Residual Melt

Tamuraite, ideally Ir5Fe10S16, occurs as discrete phases (≤20 μm) in composite inclusions hosted by grains of osmium (≤0.5 mm across) rich in Ir, in association with other platinum-group minerals in the River Ko deposit of the Sisim Placer Zone, southern Krasnoyarskiy Kray, Russia. In droplet-like inclusions, tamuraite is typically intergrown with Rh-rich pentlandite and Ir-bearing members of the laurite–erlichmanite series (up to ~20 mol.% “IrS2”). Tamuraite is gray to brownish gray in reflected light. It is opaque, with a metallic luster. Its bireflectance is very weak to absent. It is nonpleochroic to slightly pleochroic (grayish to light brown tints). It appears to be very weakly anisotropic. The calculated density is 6.30 g·cm−3. The results of six WDS analyses are Ir 29.30 (27.75–30.68), Rh 9.57 (8.46–10.71), Pt 1.85 (1.43–2.10), Ru 0.05 (0.02–0.07), Os 0.06 (0.03–0.13), Fe 13.09 (12.38–13.74), Ni 12.18 (11.78–13.12), Cu 6.30 (6.06–6.56), Co 0.06 (0.04–0.07), S 27.23 (26.14–27.89), for a total of 99.69 wt %. This composition corresponds to (Ir2.87Rh1.75Pt0.18Ru0.01Os0.01)Σ4.82(Fe4.41Ni3.90Cu1.87Co0.02)Σ10.20S15.98, calculated based on a total of 31 atoms per formula unit. The general formula is (Ir,Rh)5(Fe,Ni,Cu)10S16. Results of synchrotron micro-Laue diffraction studies indicate that tamuraite is trigonal. Its probable space group is R–3m (#166), and the unit-cell parameters are a = 7.073(1) Å, c = 34.277(8) Å, V = 1485(1) Å3, and Z = 3. The c:a ratio is 4.8462. The strongest eight peaks in the X-ray diffraction pattern [d in Å(hkl)(I)] are: 3.0106(26)(100), 1.7699(40)(71), 1.7583(2016)(65), 2.7994(205)(56), 2.9963(1010)(50), 5.7740(10)(45), 3.0534(20)(43) and 2.4948(208)(38). The crystal structure is derivative of pentlandite and related to that of oberthürite and torryweiserite. Tamuraite crystallized from a residual melt enriched in S, Fe, Ni, Cu, and Rh; these elements were incompatible in the Os–Ir alloy that nucleated in lode zones of chromitites in the Lysanskiy layered complex, Eastern Sayans, Russia. The name honors Nobumichi Tamura, senior scientist at the Advanced Light Source of the Lawrence Berkeley National Laboratory, Berkeley, California.

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