Autoclave Ammonia Leaching of Silver from Low-Grade Copper Concentrates

Karimov, К. A.; Rogozhnikov, D. A.; Набойченко, С. С.; Karimova, L. M.; Zakharyan, S. V.

doi:10.1007/s11015-018-0720-0

Cited by 4 publications

(5 citation statements)

References 3 publications

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“…2) solid/liquid ratio was chosen 1:7 and investigated e ciency of HCl, H 2 SO 4 , H 3 PO 4 and HNO 3 acids. In this way comparable with previous studies and easy to prepare [15]. Also, effect of hydrogen peroxide (H 2 O 2 ) was investigated with HCl and H 2 SO 4 media.…”

Section: Preparationsupporting

confidence: 80%

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Effect of Acidic Media During the Hydrothermal Leaching of NiTi Alloy

Özgün

Batibay

Ünal

et al. 2022

Preprint

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Nickel and titanium-based alloys are commonly used for engineering or medical applications. At the end of their lifetime NiTi alloys are recycled as additive materials. Separate recovery of metals present in NiTi alloy is possible via hydrometallurgical methods, however NiTi alloys are highly resistive towards corrosion. Different mineral acids (H2SO4, HCl, HNO3, H3PO4) have been investigated and the effect of presence of H2O2 in leaching medium has also been explored. Different leaching yields have been observed and correlation between them according to treatment conditions have been established. Microstructure and chemical properties of alloys were characterized by SEM, XRF and EDS techniques. Among mineral acids, H2SO4 and HCl illustrated the highest extraction efficiencies. Nevertheless addition of hydrogen peroxide decreased this efficiency severely. Throughout kinetics of dissolution were obtained through decreased leaching efficiency with addition of hydrogen peroxide.

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Section: Preparationsupporting

confidence: 80%

“…Studies demonstrated that using hydrothermal leaching methods under pressure in autoclave are the most suitable recovery processes [13][14][15]. Furthermore, leaching e ciency of other metals and alloys were improved by addition of oxidative chemicals like hydrogen peroxide within hydrometallurgical media.…”

Section: Introductionmentioning

confidence: 99%

Effect of Acidic Media During the Hydrothermal Leaching of NiTi Alloy

Özgün

Batibay

Ünal

et al. 2022

Preprint

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“…The method allowed the recovery of 63% of the silicon into the solution, while the cake had the following Thus, we can assume the inhibitory effect of aluminosilicates, as their layer on the particle surface prevents the diffusion of oxygen and ammonia. Aluminosilicates can also adsorb non-ferrous metals from solution [44,45]. Therefore, the direct pressure ammonia leaching of the concentrate without pre-treatment does not allow copper and silver recovery from a low-grade concentrate into the solution at temperatures below 160 • C, which is explained by the diffusion limitations created by a layer of aluminosilicates on the surface of sulfides.…”

Section: Effect Of Preliminary Desilication On Ammonia Leaching Of Lomentioning

confidence: 99%

Effect of Preliminary Alkali Desilication on Ammonia Pressure Leaching of Low-Grade Copper–Silver Concentrate

Karimov

Shoppert

Rogozhnikov

et al. 2020

Metals

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Ammonia leaching is a promising method for processing low-grade copper ores, especially those containing large amounts of oxidized copper. In this paper, we study the effect of Si-containing minerals on the kinetics of Cu and Ag leaching from low-grade copper concentrates. The results of experiments on the pressure leaching of the initial copper concentrate in an ammonium/ammonium-carbonate solution with oxygen as an oxidizing agent are in good agreement with the shrinking core model in the intra-diffusion mode: in this case, the activation energies were 53.50 kJ/mol for Cu and 90.35 kJ/mol for Ag. Energy-dispersive X-ray spectroscopy analysis (EDX) analysis showed that reagent diffusion to Cu-bearing minerals can be limited by aluminosilicate minerals of the gangue. The recovery rate for copper and silver increases significantly after a preliminary alkaline desilication of the concentrate, and the new shrinking core model is the most adequate, showing that the process is limited by diffusion through the product layer and interfacial diffusion. The activation energy of the process increases to 86.76 kJ/mol for Cu and 92.15 kJ/mol for Ag. Using the time-to-a-given-fraction method, it has been shown that a high activation energy is required in the later stages of the process, when the most resistant sulfide minerals of copper and silver apparently remain.

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“…(1) A good adaptability of raw materials and a high comprehensive utilization of resources. In the leaching kinetic conditions of high temperature and pressure, the pressure hydrometallurgy process has a fast leaching rate and is able to treat a variety of metal sulfide and oxide ores (see Figure 1) as well as complex low-grade materials, including low-grade minerals [2], arsenic-containing materials [3], multimetal-accompanying minerals, intermediate metallurgical materials, and secondary renewable resources. While extracting the main metal, it can also selectively leach and separate the accompanying rare metals or precious metals [4].…”

Section: Introductionmentioning

confidence: 99%

An Overview of Flashing Phenomena in Pressure Hydrometallurgy

Liu

Zhou

et al. 2023

Processes

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Pressure hydrometallurgy has attracted much attention for its characteristics, such as the high adaptability of raw materials and environmental friendliness. Flashing (flash boiling or flash evaporation) refers to the phase change phenomenon from liquid to gas triggered by depressurization, which is an important connection between high-pressure processes and atmospheric ones in pressure hydrometallurgy. This paper takes the flashing process in zinc leaching and alumina Bayer processes as examples, describes the flashing process in pressure hydrometallurgy in detail for the first time, and shows the importance of the flashing process in energy recovery, solution concentration, and liquid balance, as well as increasing equipment life. According to solid holdup (the volume percentage of solid), this paper proposes to divide the flashing process into solution flashing (low solid holdup) and slurry flashing (high solid holdup). A further focus is put on reviewing the state of the art of related studies. The results reveal that the research on the flashing process in pressure hydrometallurgy is scarce and often oversimplified, e.g., ignoring the BPE (boiling point elevation) and NEA (non-equilibrium allowance) in solution flashing and the effect of solid particles in slurry flashing. Computational fluid dynamic (CFD) simulation is a promising tool for investigating the flashing process. Based on the progress made in other fields, e.g., seawater desalination, nuclear safety analysis, and engine fuel atomization, we suggest that solution flashing can be studied using the CFD–PBM (population balance model) coupled two-fluid model, since a wide size range of bubbles will be generated. For slurry flashing, the effect of solid holdup on the bubble nucleation rate and mechanism as well as other bubble dynamics processes should be accounted for additionally, for which a quantitative description is still lacking. Meanwhile, data for validating the numerical method are scarce because of the harsh experimental conditions, and further research is needed. In summary, this work presents an overview of the flashing processes in pressure hydrometallurgy and some guidelines for future numerical studies.

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Autoclave Ammonia Leaching of Silver from Low-Grade Copper Concentrates

Cited by 4 publications

References 3 publications

Effect of Acidic Media During the Hydrothermal Leaching of NiTi Alloy

Effect of Acidic Media During the Hydrothermal Leaching of NiTi Alloy

Effect of Preliminary Alkali Desilication on Ammonia Pressure Leaching of Low-Grade Copper–Silver Concentrate

An Overview of Flashing Phenomena in Pressure Hydrometallurgy

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