Better knowledge of leaching characteristics of nickel sulfide minerals and gangue and processing characteristics of sulfide concentrates can improve recoveries and kinetics during leaching, particularly in the development of lower cost leaching options possibly carried out at atmospheric pressure or without the need for ultra-fine grinding as ...Web

In this review, the main mathematical models of leaching and all possible scenarios are presented and discussed. The effect of various leaching parameters …Web

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

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

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

This research was aimed to investigate the leaching behavior of zinc and copper from a porcelain stone tailings sample using RSM-CCD modeling. The synergetic and individual effects of five main factors including liquid/solid ratio, sulfuric acid concentration, agitation speed, leaching time, and temperature were examined on the …Web

The economic and technical values of the hydrometallurgical or leaching processing are a function of its reaction rates and these reaction rates are enhanced by mechanical activation (MA) in hydrometallurgical processing. This study presents a novel derived theoretical model for MA-assisted leaching in investigating the effects of ball mill …Web

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

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 2 SO 4, HCl, HNO 3, and their mixtures) at room temperature to boiling point temperature and various acid concentrations (1.5 to 3.0 mol/L), ratios of waste to solution ...Web

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

Insight into the effects of grinding media on the flotation kinetics of chalcopyrite. ... for low leaching rates in the curing-leaching process of vanadium-bearing stone coal and to find a ...Web

W recovery was 4.8 times higher at 38 °C, 1.8 times higher at 60 °C, and 0.5 times lower at 80 °C after 6 h of leaching, meaning that the grinding improved the leaching kinetics for the lower temperatures, but …Web

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

The results have shown that the ball movement regime for good grinding efficiency of the planetary ball mill is "cascading" or light "cataracting", and contact forces have a greater effect on the grinding of powders than collision forces. ... Comparison of atmospheric citric acid leaching kinetics of nickel from different Indonesian ...Web

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

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

Liu et al. (2012) investigated the leaching kinetics of copper from low-grade copper ore containing calcium-magnesium carbonate in an ammoniacal leaching medium. When leaching carbonaceous ore, an ammoniacal leaching medium is occasionally preferred over an acid medium because it does not react with carbonates and siliceous …Web

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

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

The effects of grinding fineness, sulfuric acid concentration, liquid-to-solid ratio, agitation rate and leaching time on the leaching efficiency were studied to optimize the traditional hydrometallurgical process. Moreover, the kinetic model of the leaching process was investigated. 2. Materials and methods2.1. MaterialsWeb

However, Mo extraction was increased significantly after co-grinding of MoS 2 with NaClO 2 and Na 2 CO 3, e.g., more than 58% in any leaching solution applied. Prolonging the grinding time improved Mo extraction but the efficiency was declined gradually, giving rise to an optimum grinding efficiency at 4 h with a molar ratio of 1:3:5 …Web

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

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

The sulfuric-acid leaching kinetics of nickel as the main component of grinding wastes originating from machining a rhenium-containing heat-resistant ZhS …Web

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

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

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

The particle coarsening appears when the grinding time increases to 120 min from 100 min. A fitted grinding kinetics function of MMS has been established based on the measured PSDs with six grinding time. ... The leaching kinetics of alumina extraction from coal gangue with hydrochloric acid was investigated. The effects of …Web

The leaching rates were slow and the activation energy was estimated to be 116 kJ/mol. The addition of sulphate ions to the FeCl3-HCl system reduces the tetrahedrite leaching rate to values similar to those realized in the Fe2(SO4)3-H2SO4 system. However, the rate of dissolving mineral particle in leaching process decreasesWeb

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

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

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

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

The effect of mechanical activation on the atmospheric pressure leaching of a lateritic nickel ore was investigated to develop a superior alternative. Under the influence of mechanical activation, certain physico-chemical changes were observed. Accelerated leaching kinetics and less sulfuric acid consumption were found as the …Web

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

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

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

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

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

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