Kinetics of Extracting Vanadium from Stonecoal by Alkali Leaching
The kinetics analysis for the process is presented by the shrinking core model. The results show that the vanadium leaching ratio of roasted stone coal can be beyond 75% at the …Web
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Thermal and Mechanical Activation in Acid Leaching Processes …
The dissolution kinetics of aluminosilicate minerals is highly related to their crystal structure during leaching. In general, these minerals are known for their low solubility and slow dissolution. The crystal lattice of these minerals is characterized by strong covalent or ionic Si–O bonds forming tetrahedral layer, and ionic Al–O bonds ...Web
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Leaching Kinetics of Rare Earth Elements from Fire Clay Seam …
The kinetic data obtained from leaching over a range of temperatures suggested that the leaching process follows the shrinking core model with possibly a mixed control mechanism that may be a result of several heterogenous materials leaching simultaneously. ... The high ash-based REE content value provided an indication that the …Web
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Kinetics and Optimization of Metal Leaching from Heat-Resistant …
The kinetics and conditions of the acid leaching process of the grinding waste of a heat-resistant nickel alloy are studied depending on the composition of the acid solution (H …Web
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Mechanical activation in hydrometallurgy
The review paper deals with the results of the utilization of mechanical activation in hydrometallurgy. The definition of mechanochemistry is given as well as physicochemical changes in mechanically activated minerals are described. The enhancement of the leaching processes in hydrometallurgy is illustrated. The chemical …Web
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A fundamental study of leaching kinetics and mechanisms of …
Fig. 2 (b) shows the effects of grinding ball size (60 g) on Mo extraction, with the grinding and leaching conditions being same to that applied in Fig. 2 (a). It can be seen that Mo extraction was remained at approximately 60% when the diameter of grinding ball was increased from 3 mm to 10 mm. ... Selective leaching kinetics of low-grade ...Web
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Kinetics of Extracting Vanadium from Stonecoal by Alkali Leaching
Vanadium was leached from roasted stone coal by NaOH solution, and the effect of leaching temperature, leaching time, addition of NaOH liquid to solid ratio, the grinding fineness of stone coal, and stirring speed on the vanadium leaching rate was studied. The kinetics analysis for the process is presented by the shrinking core model. …Web
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Leaching Kinetics of Valuable Metals
1. Introduction and Scope Leaching is a primary extractive operation in hydrometallurgical processing, by which a metal of interest is transferred from naturally-occurring minerals …Web
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Effect of activator on kinetics of direct acid leaching of vanadium
The leaching efficiency is the key parameter for the acid leaching of vanadium without roasting, a high leaching efficiency is often obtained by fine grinding or pressurization. It was found that the clay vanadium ore can be easily slimed after fine grinding, and the resulting fine slime will give rise to problems such as difficult …Web
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Fundamental kinetic models for gold ore cyanide leaching
Semantic Scholar extracted view of "Fundamental kinetic models for gold ore cyanide leaching" by D. Rubisov et al. ... ore was investigated within a diagnostic approach. Ultrafine grinding prior to cyanide leaching was also examined to enhance the … Expand. 2. PDF. 1 Excerpt; Save. Integrated modeling of grinding, liberation and leaching of ...Web
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Surface chemistry of oxidised pyrite during grinding: ToF-SIMS …
The various factors affecting TCCA leaching carbonaceous pressure-oxidized gold ore were investigated and the leaching kinetics were established. According to the results of orthogonal experiments, ... Beneficial effects emerging from the chemical conditioning during grinding were observed regarding kinetics, selectivity, and overall ...Web
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Kinetics and mechanisms of leaching of rare earth elements from
The controlling mechanisms could be determined via the kinetics curves of the amount of leached metals as a function of time. Case studies of REEs leaching …Web
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Grinding kinetics of lead–zinc tailing powders and its optimal …
In addition, the leaching toxicity of Pb, Cr, and Cd of LZTPs cement mortar block is below the standard limit of TCLP 1211 and it is safe to use the mortar with the addition of 30% LZTPs. ... This study aims to explore grinding kinetics, particle characteristics of LZTPs, the optimal economic grinding time, and particle size range as …Web
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Direct leach approaches to Platinum Group Metal (PGM) ores and
Where appropriate, the key thermodynamic and kinetic factors are given and compared. Introduction. The ... 2002). Ore is first ground by conventional multistage crushing and ball milling, or by semi-autogenous grinding (SAG), and then smelted. The matte is hydrometallurgically treated to leach and separate Fe, Co, Ni and Cu leaving a …Web
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Eco-friendly and reagent recyclable gold extraction by iodination
The kinetic analysis shows that the gold leaching process conforms to the shrinkage kinetics model, and the control step was the solid film diffusion control. The apparent activation energy of this reaction was 8.642 kJ/mol, and the reaction order of initial iodine concentration and initial iodide ion concentration were 0.72 and 0.52, respectively.Web
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Metals | Free Full-Text | Leaching Kinetics of Valuable Metals
The kinetics of dissolution of refractory sulfide gold-containing concentrates of the Yenisei ridge (Yakutia, Russia) by a solution of HNO 3 in the temperature range of …Web
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Metals | Free Full-Text | Vanadium–Titanium Magnetite …
The pellet calcium and magnesium complex roasting leaching kinetics were improved, and the subsequent vanadium leaching effect was enhanced. The optimal conditions for acid leaching were a sulfuric acid concentration of 3.0 mol/L, a liquid-to-solid ratio of 4:1, a leaching temperature of 80 °C, and a time of 75 h.Web
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Frontiers | Thermodynamics and Kinetics of Sulfuric Acid Leaching
The stable zone of HF and Nd 3+ was determined from the ɛ-pH diagram, and the reaction conditions were controlled so that NdF 3 could be converted into HF and Nd 3+ as much as possible to ensure the smooth progress of sulfuric acid leaching reaction.It can be seen from Figures 4–7 that with the increase of temperature and activity, the stability …Web
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Kinetics of Sulfuric-Acid Nickel Leaching from the Grinding …
To study the kinetics, a grinding waste fraction (–0.071 mm) obtained with the greatest yield (49.2 wt %) has been used. Convex kinetic curves of nickel leaching from the wastes have been obtained. It has been revealed that, when the temperature changes from 55 to 85°С, the time until the leaching stopsWeb
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Vanadium Transitions during Roasting-Leaching …
In this work, we investigate the vanadium occurrence, not only in stone coal but also in the water leaching and acid leaching residues, to seek the root of the relatively inferior vanadium recovery during the roasting-leaching …Web
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Kinetics of Sulfuric-Acid Nickel Leaching from the Grinding …
The sulfuric-acid leaching kinetics of nickel as the main component of grinding wastes originating from machining a rhenium-containing heat-resistant ZhS-32VI superalloy and containing the impurities of abrasive materials, oils, ceramics and other pollutants has been studied in the agitation mode concentrating refractory metals in the …Web
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A study of the grinding of magnetite/limestone mixture in a stirred
The batch grinding kinetic equation is given by a rate-mass balance equation: dR i t dt = − S i t R i t + ∑ j = 1 i − 1 b ij S j t R j t n ≥ i ≥ j ≥ 1. Materials. Magnetite (Moh's hardness of 5.5–6.5) and limestone (Moh's hardness of 3.0) were used as the feed for grinding experiments, which were obtained from Lingshou County, China.Web
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Kinetics of nickel leaching from low-nickel matte in sulfuric acid
Additionally, the subsequent treatment of the high-nickel matte after the grinding and flotation processes is complicated, and leads to the dispersion of noble metals. Usually, the loss of noble metals is about 10% ~ 20%. ... More importantly, a mathematical model of the leaching kinetics is used to identify the rate determining step of ...Web
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(PDF) Kinetics of leaching: a review
Kinetics, as a fundamental requirement of nearly all industrial activities and engineering researches, plays a great role in leaching processes. Although there are many pieces of research on...Web
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Kinetics of leaching: a review
Kinetics, as a fundamental requirement of nearly all industrial activities and engineering researches, plays a great role in leaching processes. Although there are many pieces of research on its application, there is not a clear pathway for investigating the kinetics of leaching and researchers usually follow different strategies in their studies. The …Web
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Improving the gold leaching process of refractory ores using the
Abstract. Gold ores have been a subject of numerous investigations aimed at enhancing gold recovery and improving leaching kinetics. This is because the cyanidation process cycle, although well established and well researched, remains a process of long duration. To reach the acceptable gold recoveries i.e., +80%, some ores are leached for …Web
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Liuyi REN | Associate Professor | PhD | Wuhan University
Grinding, as an important preparation step for beneficiation is very necessary to study for the finely disseminated extent, vanadium-bearing stone coal with complex chemical composition.Web
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MECHANOCHEMICAL TREATMENT IN METALLURGY AN …
Mechanochemical treatment to enhance leaching kinetics has the potential to be effective for leaching of minerals like chalcopyrite, tetrahedrite, wolframite, scheelite, etc., which all are ... One of the keys to obtain high and fast kinetics has been ultrafine grinding with particle sizes (d80) down to 5-15 µm. A number of processes have been ...Web
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Kinetic Investigation on Leaching of Copper from a Low-Grade
In this study, the reject fraction of the jaw crusher, located in the first part of the crushing circuit, is used as a considerable stock in copper tank-leaching plant. High market value of copper and ease of practice were the motivating forces on studying the leaching kinetics under controlled conditions. In this regard, first, the influencing …Web
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Kinetics of Sulfuric-Acid Nickel Leaching from the Grinding …
The sulfuric-acid leaching kinetics of nickel as the main component of grinding wastes originating from machining a rhenium-containing heat-resistant ZhS …Web
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