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Shuang Qiu - One of the best experts on this subject based on the ideXlab platform.

  • leaching of a complex sulfidic silicate containing zinc Ore in sulfuric acid solution under oxygen pressure
    Separation and Purification Technology, 2012
    Co-Authors: Chang Wei, Gang Fan, Zhigan Deng, Xuejiao Zhou, Shuang Qiu
    Abstract:

    Abstract This paper reports an acid leaching process study on the selective extraction of base metals from complex sulfidic, silicate-containing zinc Ore containing sphalerite, hemimorphite, smithsonite, quartz, galena, pyrite, troilite, muscovite, calcium aluminate, calcite, gypsum and cerussite with traces of other minerals under oxygen pressure. The effects of influential factors (leaching temperature, sulfuric acid concentration, leaching time, Ore Particle size distribution, liquid/solid ratio and pressure) on the dissolution efficiencies of zinc, iron and silica from said Ore were investigated. The optimum conditions, which were sought for reducing downstream purification requirements by limiting iron and silica dissolution, were found to be a leaching temperature of 160 °C, a liquid/solid ratio of 6 mL/g, a sulfuric acid concentration of 0.42 mol/L, a leaching time of 150 min, a Particle size of −98 + 74 μm and 1.6 MPa partial pressure. Under these conditions, the zinc extraction was above 97%, with an iron and silica dissolution of less than 25% and 0.3%, respectively. The reduction of silica dissolution during leaching also promotes easier solid–liquid separation.

Yanxin Wang - One of the best experts on this subject based on the ideXlab platform.

Zhi Hong Zheng - One of the best experts on this subject based on the ideXlab platform.

E A Abdelaal - One of the best experts on this subject based on the ideXlab platform.

  • kinetics of sulfuric acid leaching of low grade zinc silicate Ore
    Hydrometallurgy, 2000
    Co-Authors: E A Abdelaal
    Abstract:

    Abstract The results of a leaching kinetics study of low-grade zinc silicate Ore with sulfuric acid are presented. Effect of Ore Particle size, reaction temperature, and acid concentration on zinc dissolution rate were determined. The results obtained show that leaching of about 94% of zinc is achieved using −200+270 mesh Ore Particle size at a reaction temperature of 70°C for 180 min reaction time with 10% sulfuric acid concentration. The solid:liquid ratio was maintained constant at 1:20 g/ml. Leaching kinetics indicate that diffusion through the product layer is the rate controlling process during the reaction. The activation energy was determined to be about 3.2 kcal/mol, which is characteristic for a diffusion-controlled process.

Shikang Qin - One of the best experts on this subject based on the ideXlab platform.

  • Quantitative Study on the Contact Force and Force Chain Characteristics of Ore Particle Systems during Ore Drawing from a Single Drawpoint under the Influence of a Flexible Barrier
    Geofluids, 2020
    Co-Authors: Qingfa Chen, Shikang Qin
    Abstract:

    It is of great significance to carry out quantitative research on the contact force chain characteristics of Ore Particle systems during Ore drawing to reveal the microscopic and mesoscopic characteristics of Ore Particle systems during implementation of the synchronous filling shrinkage stoping method. Based on the Particle discrete element method, combined with the relevant knowledge of contact mechanics and statistical mechanics, microscopic properties of the Ore Particle system were studied quantitatively. (1) The probability distributions of the normal and tangential contact forces during Ore drawing from a single drawpoint under a flexible barrier are similar, and both show exponential decay. (2) In the regions on both sides of the model, the Ore Particles will not be released because they are far from the drawpoint; there, the coordination number is stable, and the density of contact network is large. In the upper part of the drawpoint, Ore Particles flow, the coordination number fluctuates violently, and the density of contact network is small. (3) In the initial stage, the stress distribution of the Ore Particle system is uniform, and the strong force chain does not show obvious directivity. After that, the directions of the strong force chains in the Ore Particle system are inclined to the vertical direction, and the strong force chains mainly bear the load in the vertical direction. (4) In the initial stage of drawing, the normal contact force is mainly concentrated in the vertical direction. With the progression of drawing, the normal contact force at an angle of 30° to the horizontal direction increases gradually, and the number of the main direction of the average contact force distribution changes from one to three (the vertical direction and the direction with a ±30° angle to the horizontal direction).

  • Correlation between Ore Particle flow pattern and velocity field through multiple drawpoints under the influence of a flexible barrier
    Open Geosciences, 2019
    Co-Authors: Shikang Qin, Qingfa Chen, Qinglin Chen, Fuyu Zhao
    Abstract:

    Abstract By means of similar tests, the stope room is scaled and the process of multiple-drawpoint Ore drawing under the influence of a flexible barrier is simulated by the marking Particle method. Based on the experimental phenomena and data, the shape of the barrier, the draw column, and the numerical relations for the discharge between each drawpoint are analysed. The velocity equation for Ore Particles flowing through multiple drawpoints is established and the relationship between Ore Particle flow properties and velocity fields is found. Finally, the following results are derived: 1) For each layer, the morphology of marked Particles is similar to that of vertical velocity. The Particles are quasi-linear in the upper part of the model and wavy in the lower part. The amplitude increases with decreasing height. 2) The distribution of thirteen concentric points of horizontal velocity in each layer illustrate that the Ore Particles drawn from each drawpoint are from the centreline between it and the adjacent drawpoint. 3) The barrier and the marked Particles are at the lowest sag points at the top of the number two and number six drawpoints (close to the model’s side wall) because of the combination of vertical velocity and horizontal velocity.

  • Stress analysis of Ore Particle flow behaviour under the influence of a flexible barrier
    Arabian Journal of Geosciences, 2019
    Co-Authors: Qingfa Chen, Shikang Qin, Qinglin Chen
    Abstract:

    Additional stresses caused by a flexible barrier, drawpoints and the self-weight of Ore Particles were investigated based on a physical experiment of the shrinkage stoping method of synchronous filling, and the flow behaviour of Ore Particles is described by the component forces. This study shows that when Ore Particles are drawn from multiple drawpoints under the influence of a flexible barrier, the stress distribution of the Ore Particles is sinusoidal, with an amplitude that gradually decreases with increasing height. The values of σx and σy gradually decrease with increasing height; the maximum σy values occur at x = 0, the maximum σx values occur at x = ± 10 and the maximum shear stresses occur near the lateral walls. The shape of the draw column is determined by the additional vertical stress, and its contour determines the essential morphology of the drawbody. The surface of the Ore Particles is smoothed by the additional stress caused by the barrier, and the self-weight of the Ore Particles is the inherent cause of the additional stress.

  • Numerical Simulation of Ore Particle Flow Behaviour through a Single Drawpoint under the Influence of a Flexible Barrier
    Hindawi-Wiley, 2019
    Co-Authors: Qingfa Chen, Shikang Qin, Qinglin Chen
    Abstract:

    A model of the mass draw and synchronous filling no-top-pillar shrinkage stoping method was created based on the Particle element theory and PFC2D software. A numerical simulation of the Ore Particle flow behaviour through a single drawpoint under the influence of a flexible barrier was performed; following which, a visualization of the change process in the marked layers, draw column, flexible barrier, and cavity was obtained. Finally, the results demonstrated the following. (1) BefOre the Ore Particles at the highest horizon were drawn, the morphology of the draw column had an ellipsoidal (whole, closed, and approximate) shape, but after the Ore Particles were drawn, the morphology of the draw column had a gyroscopic shape (i.e., the shape of a spinning top). (2) The height of the draw column increased rapidly and exponentially in the early period of the draw, presented a linear growth tendency during the medium period with an increase in the accumulated mass drawn, and remained at a certain value in the later period. (3) The morphology of the flexible barrier presented a Gaussian distribution on the whole, but its bottom had an analogous parabola morphology, particularly in the late stage. (4) The cavity began to form with the Ore Particles at the highest horizon drawn; the cavity development presented an evolutionary process from the microscopic to macroscopic regime, and the morphology of the cavity was crescent in the early stage and triangular in the late stage