Effect of Magnesium Sulfate Solution on Pore Structure of Ionic Rare Earth Ore during Leaching Process

Gao, Zhongquan; Rao, Yunzhang; Shi, Liang; Xiang, Run; Yang, Zhihua

doi:10.3390/min13020294

Cited by 6 publications

(4 citation statements)

References 23 publications

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“…The gas in the pores was gradually replaced by pore solution, and the pore solution volume, the saturation, and the conductive path 2 in Figure 2 increased. The micro and small pores in the ore body evolved into medium and large pores under the action of seepage, and the pore size of the ore body increased, the seepage effect was enhanced, and the solution connectivity was improved [51][52][53][54][55]. Due to the continuous addition of ammonium sulfate leaching solution, the number of ions in the pore solution increased, and the improvement in pore connectivity led to an increase in the freely moving anion number in the solution, so the conductive capacity of the solution was enhanced.…”

Section: Equivalent Circuit Parameter Analysismentioning

confidence: 99%

Characteristics of Electrical Resistance Alteration during In Situ Leaching of Ion-Adsorption-Type Rare Earth Ore

Feng,

Wang

2024

Minerals

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The chemical reaction of ion-adsorption-type rare earth ore during the in situ leaching process is accompanied by ion migration and charge movement, making the leaching process electrochemical in nature. The chemical reaction rate plays an important role in the leaching rate of rare earth elements. In this work, electrochemical impedance spectroscopy (EIS) was used to reveal the characteristics of electrical resistance alterations and leaching rate of rare earth elements during in situ leaching. The equivalent circuit model of the leaching process was established, and two critical parameters of solution resistance Rs and charge transfer resistance Rt were analyzed to reflect the electrochemical characteristics. According to the characteristics of electrical resistance alteration, the leaching process was divided into four stages: wetting, reaction, equilibrium, and top water stage. The resistance parameters Rs and Rt decreased first and then increased during the leaching process. The maximum value of Rs was 1330 Ω∙cm2 at the end of the top water stage, and the minimum value was 125 Ω∙cm2 at the beginning of the equilibrium stage. The maximum value of Rt was 8310 Ω∙cm2 at the beginning of the leaching stage, and the minimum value was 21 Ω∙cm2 at the end of the reaction stage. Rs and Rt were negatively correlated with the pore size and chemical reaction rate during leaching. With an increasing pore size and reaction rate, the resistance parameters decrease. This study provides a new idea for the intelligent monitoring of rare earth ore.

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Section: Equivalent Circuit Parameter Analysismentioning

confidence: 99%

Characteristics of Electrical Resistance Alteration during In Situ Leaching of Ion-Adsorption-Type Rare Earth Ore

Feng,

Wang

2024

Minerals

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“…The variation of surface potential was also the largest, increasing by 49.77%. Due to the strong hydrophobicity of the surface of rare earth minerals, more Mg 2+ entered the particle surface, and the ionized impurity ions were adsorbed onto the particle surface to compress the double layer, resulting in a decrease in the absolute value of Zeta potential [5,38,39].…”

Section: Comparative Analysis Of Zeta Potential and Surface Potential...mentioning

confidence: 99%

“…It mainly exists on the surface of minerals in the form of ions, such as halloysite, illite, kaolinite, and a small amount of montmorillonite in the deposit. The only way to extract rare earth elements is to use a salt electrolyte solution to leach ion-adsorbed rare earth deposits [2][3][4][5]. Flotation is usually used to pre-treat ores containing valuable metals before leaching [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Calculation of Shear Layer Thickness of Ionic Rare Earth Particles in Mixture Electrolytes during In-Situ Leaching Process

Gao,

Rao,

Zhang

et al. 2023

Minerals

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During in-situ mining and leaching of ionic rare earth ore, a chemical replacement reaction occurs between the leaching agent and rare earth ore. The thickness of the shear layer on the surface of colloidal particles is an important physical parameter. Based on the Gouy–Chapman double-layer theory and Poisson–Boltzmann equation, the relational expression for the thickness of the shear layer in the electric double layer on the particle surface under the condition of 2:2 + 3:2 mixture electrolytes (MgSO4 + RE2(SO4)3) is derived. On this basis, an indoor column leaching experiment of MgSO4 solution is conducted, and the surface Zeta potential of rare earth ore particles is measured using a Zetaprobe potential analyzer. The surface potential and the thickness of the shear layer in the leaching process with different concentrations solutions (2.5%, 3.0%, and 3.5%) are calculated. The effects of a MgSO4 solution concentration and particle surface potential on the thickness of the shear layer in the electric double layer are analyzed. It provides a theoretical basis for the study of the internal seepage of the ore body under the condition of the coexistence of multiple ions in the leaching process.

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“…In this experiment, only the process from non-saturation to saturation of the ore sample was tested. Gao et al [26] found that the porosity did not change during the saturation process when the ore was leached with clean water. Thus, the test was not conducted after saturation.…”

Section: Fitting and Analysis Of Swccmentioning

confidence: 99%

Experimental Study on Pore Structure and Soil-Water Characteristic Curve of Ionic Rare Earth Ore under Seepage

et al. 2023

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The ionic rare earth (RE) ore body undergoes particle transport and pore structure change during the leaching process, resulting in "uneven percolation, preferential channel, leaching blind area," and other problems, leading to structural changes in the ore body, low leaching efficiency, and waste of resources. The unsaturated infiltration process is also the key stage that causes these problems. The initial pore structure evolution of the ore body plays a decisive role in the permeability coefficient of the ore body, and the direct influencing factor of the permeability coefficient is the distribution of the pore radius. We carried out research through indoor simulated leaching, the filter paper method for determining matrix suction, and nuclear magnetic resonance (NMR) testing. An ionic rare earth ore soil-water characteristic curve within a large matrix suction range was obtained by the filter paper method. With the increase in volumetric water content, the matrix suction presents a sharp downward trend. When the volumetric water content is less than 20%, this rule is particularly obvious. With the increase in matrix suction, the thickness of the adsorbed water film on the particle surface and pore radius show a decreasing power function trend. Under percolation, the porosity of an ionic rare earth ore sample tends to increase linearly with the increase in volumetric water content during the process from non-saturation to saturation; the porosity of a saturated ore sample after seepage expanded by 17.5 times compared to that of an unsaturated ore sample before seepage. The change rule of the internal microstructure of the ore sample is reflected in the gradual disappearance of micro pores and the gradual formation of small, medium, large, and mega pores, which shows a gradual increase trend. In the pore radius distribution, the more large and medium pores, the larger the permeability coefficient; the more micro and small pores, the smaller the permeability coefficient. For some ore bodies with poor permeability, the ore body is infiltrated with clear water under small water pressure before leaching with a leaching solution, which can improve the permeability of the ore body, effectively improve the efficiency of rare earth leaching, and increase the economic benefits.

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Effect of Magnesium Sulfate Solution on Pore Structure of Ionic Rare Earth Ore during Leaching Process

Cited by 6 publications

References 23 publications

Characteristics of Electrical Resistance Alteration during In Situ Leaching of Ion-Adsorption-Type Rare Earth Ore

Characteristics of Electrical Resistance Alteration during In Situ Leaching of Ion-Adsorption-Type Rare Earth Ore

Calculation of Shear Layer Thickness of Ionic Rare Earth Particles in Mixture Electrolytes during In-Situ Leaching Process

Experimental Study on Pore Structure and Soil-Water Characteristic Curve of Ionic Rare Earth Ore under Seepage

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