Thus, it can be determined that the kinetic equation of leaching of low-grade magnesite in ammonium bisulfate solution is consistent with the surface chemical reaction model. Fig. 6 (a) Plots of 1 − 2/3x − (1 − ... Based on the kinetic data in this study, the above analysis further suggests that the leaching process of low-grade magnesite ...Web

In the present investigation, the kinetic study of the hydrometallurgical based leaching of Zn and Cu from the spent low-temperature shift catalyst (CuO/ZnO/Al 2 O 3) have been performed. Additionally, the process parameters affecting the leaching process have been optimized by Taguchi's orthogonal array design.Web

The goal of this study was to investigate the influence of leaching temperature on Ni and Fe recovery, as well as the best kinetic model to represent the leaching process of these metals.Web

A novel process for the integral treatment of polymetallic sulphide ores is proposed. The process consists of a global flotation, two stages of ferric leaching, the first stage dissolves the sphalerite and the rest of secondary sulphides, and the second dissolves the chalcopyrite with a silver catalyst, and finally a brine leaching to recover lead and …Web

respectively. The apparent activation energy for the leaching process has been calculated using the Arrhenius expression and was found to be 51.7 kJ/mol. Keywords: low-grade manganese ore; pretreated sawdust; reductive leaching; kinetic study 1. Introduction Manganese, one of the important strategic metals, is widely used in metallurgy, the ...Web

The results of a leaching kinetics study of spent nickel oxide catalyst with sulfuric acid are presented. The effects of spent catalyst particle size, sulfuric acid concentration, and reaction temperature on Ni extraction rate were determined. The results obtained show that extraction of about 94% is achieved using −200+270 mesh spent ...Web

The current study was carried out to investigate the kinetics of pressure leaching of niobium ore in sulfuric acid media. The effects of stirring speed, oxygen pressure, sulfuric acid concentration, particle size and temperature on the leaching efficiency of niobium were studied. ... A kinetic study of the leaching of a low-grade …Web

This study aims to develop a mathematical model that can explain the mechanism of the leaching process of laterite ore using a low concentration of the citric acid solution and evaluate that model ...Web

A new leaching process for a low-grade refractory tantalumniobium ore by KOH sub-molten salt was studied. The effects of leaching temperature, initial KOH …Web

Kinetics, as a fundamental requirement of nearly all industrial activities and engineering researches, plays a great role in leaching processes. Although there are …Web

Abstract: Process improvement and kinetic study on copper leaching from low-grade cuprite ores in sulfuric acid solution are presented in this paper. Effects of major leaching parameters on copper leaching efficiency are determined. The results indicate that copper minerals in the raw ores are mainly cuprites.Web

Kinetic data obtained from leaching over a range of temperatures shows that leaching with higher concentrations follows the diffusion reaction. Based on the results of the percentage recovery in various operating conditions, the best conditions were at a concentration of 6 mol/L with a temperature of 60 °C which reached a percentage of more ...Web

High-sulfur coal gangue (HS-CG) is extremely unstable in the environment, releasing acid mine drainage with high concentrations of harmful heavy metals (HMs). The effects of HS-CG particle size, leaching solution pH, Fe 3+ and acidophilic microorganisms on the release of HMs from the HS-CG and their kinetic behavior were studied using …Web

The optimal leaching recovery of Mo was attained at 94.96% within a leaching of 20 min, whereas the leaching ratio of Al was maintained in a low level. From the current researches, it is apparent that the combinations of ultrasound and organic acids or other techniques can largely promote the dissolution of Mo from various secondary …Web

Kinetic Investigation on Leaching of Copper from a Low-Grade Copper Oxide Deposit in Sulfuric Acid Solution: A Case Study of the Crushing Circuit Reject of a …Web

In this work, a novel approach of leaching valuable metals, such as niobium, yttrium and cerium, from a niobium-bearing ore of low grade by roasting …Web

In the current study, a numerical mechanistic kinetic model for direct leaching of zinc from iron containing sphalerite concentrate is presented. The model is based on the well-known shrinking-core model approach. However, in order to consider possible chemical changes that might take place in the liquid phase the model is solved …Web

Therefore, it is necessary to explore the leaching behavior of low nickel matte in the presence of solutions saturated with sulfate. In this study, the leaching kinetics of low nickel matte in H 2 SO 4 solutions saturated with FeSO 4 and NiSO 4 was investigated. Kinetic data of the dissolution of nickel for various parameters showed best fit to ...Web

Kinetic models were also evaluated to determine the rate-limiting step of the sphalerite leaching; it was concluded that the type of the sulfur layer formed in the residue (porous or non-porous ...Web

A kinetic study of the leaching of a low-grade niobium–tantalum ore by concentrated KOH solution under atmospheric pressure has been investigated. The …Web

Leaching kinetics of K, S, ash, N, and Cl (the trend line shown in each figure is of the second-order kinetics model, and the data points are from the experimental results). Comparison between ...Web

Process improvement and kinetic study on copper leaching from low-grade cuprite ores in sulfuric acid solution are presented in this paper. Effects of major …Web

In this paper, leaching characteristics are presented, and a cost-effective process for extracting uranium, copper, and cadmium from Talet Seleim's Gibbsite is developed. H2SO4 was chosen as the preferable leaching agent based on the agitation experiment's findings. The leaching efficiencies of U, Cu, and Cd attained 95%, 90%, …Web

The inefficient leaching of manganese is the main factor hindering the commercialization of the reduction process during manganese recovery using pyrite as the reducing agent. Hence, a new method for improving recovery efficiency and reducing the cost is required. This study uses microwave heating as a strengthening method to …Web

A kinetic study of the leaching of a low-grade niobium–tantalum ore by concentrated KOH solution under atmospheric pressure has been investigated. The effects of reaction temperature, KOH concentration, agitation speed, particle size and alkali-to …Web

The kinetics of the leaching process of oxide minerals depends on the activity of the protons in the solution (Kursunoglu & Kaya, 2016). The kinetic study was carried out using a shrinking core model, in which the mathematical equation follows the equation from Astuti et al. (2015), Mubarok & Fathoni (2016), Wanta et al. (2018), and Xiao et al ...Web

For adsorption kinetic study, the reaction time varied from 0 to 100 min with solution initial concentration of 100 mg/L at 298 K. For adsorption isotherms study, solution initial concentrations ranged from 60 to 200 mg/L with reaction time 24 h at 298 K, 318 K and 338 K, respectively. ... In this research, the low-cost acid leaching ...Web

Kinetic data are obtained for the leaching of Raney Ag–Al alloy (50 wt% Ag) at constant temperature and constant alkali concentration in the temperature range of 283–313 K for different average particle size.The data fit well into a developed model based on autocatalytic reactions, log(y/(1−y))=−a/t+ab, where y is the fractional leaching, t is …Web

The kinetic analysis was carried out based on the shrinking core model, which indicated that the reductive leaching process was controlled by the chemical reaction. The …Web

In this research work, the pressure leaching of chalcopyrite concentrate with oxygen was studied. Experiments were carried out under conditions of the solid–liquid ratio of 0.1, agitation speed of 750 rpm, and sulfuric acid concentration of 2 M in a stainless-steel autoclave system under 0.6 to 1 MPa oxygen gas. Central composite design was used to …Web

Kinetic Study of the Leaching of Low-Grade Manganese Ores by Using Pretreated Sawdust as Reductant by Yang Sun, Gaofeng Fu * and Lan Jiang School of …Web

A kinetic study of the leaching of manganese mining residue by sulphuric acid and potassium oxalate has been investigated. The effects of the agitation speed, manganese ore particle size, acid concentration, oxalate concentration and temperature on the manganese dissolution rate was determined. The leaching rate is significantly …Web