Removal of impurity Pb during crude selenium purification by controlling potential oxidation and vacuum distillation

Luo, Huan; Jiang, Wenlong; Zha, Guozheng; Zhen, TianTian; Yang, Bin; Xu, Baoqiang

doi:10.1016/j.vacuum.2021.110674

Cited by 12 publications

(4 citation statements)

References 16 publications

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“…The above processes can achieve mercury removal and crude selenium purification, but the waste liquid containing selenium needs to be disposed of in an environmentally friendly manner, which complicates the process. In recent years, some physical methods such as fractional crystallization and controlling potential oxidation-vacuum distillation have been used to remove Hg from crude selenium [14,15].…”

Section: Introductionmentioning

confidence: 99%

Combined Sulfidation and Vacuum Distillation for the Directional Removal of Hazardous Mercury from Crude Selenium

Zha

2023

Metals

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In this work, an innovative process involving directional sulfurization–vacuum distillation is proposed to effectively remove trace levels of mercury impurities from crude selenium. First, a reaction between sulfur and mercury is used to break the strong chemical Se-Hg bond to achieve the sulfide mineralization of mercury. Second, selenium and mercury are separated by vacuum distillation based on a difference in volatility. Thermodynamic analysis confirms the feasibility of this method. The experimental results show that the sulfidation reaction potential energy of different sulfidizing agents is in the order S > Na2S > FeS, and the optimum conditions are determined to be the following: a sulfidation temperature of 473 K and time of 30 min, and vacuum distillation experimental parameters of 503 K, 60 min, and 10–20 Pa system pressure. The overall experimental results show that the maximum removal of mercury is 97.49%. The content of mercury in the refined selenium was reduced from 0.32% to 0.0088% in the volatile matter. The results have practical value for the separation of selenium and mercury from hazardous wastes.

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Section: Introductionmentioning

confidence: 99%

Combined Sulfidation and Vacuum Distillation for the Directional Removal of Hazardous Mercury from Crude Selenium

Zha

2023

Metals

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“…With the increasing demand for indium in the high-tech field, the purity of indium has become more demanding. High-purity indium is mainly used in semiconductors, fluorescent materials, ITO films, and photovoltaic solar cells ( Xu et al, 2021 ; Luo et al, 2022 ). In addition, high purity indium has become the top classification of critical materials due to its wide application, such as liquid crystal displays and light-emitting diodes ( Fontana et al, 2015 ; Rakhymbay et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

“…Pettit et al ( 2002 ) researched the kinetics of indium deposition on molybdenum substrates and concluded that SHG and FFT-EIS can be used to investigate electrodeposition surface modification processes. Luo et al ( 2022 ) analyzed the removal mechanism of lead and the behavior of selenium in the purification process by controlling the potential oxidation and vacuum distillation, indicating that lead impurities can be removed by combining these two methods effectively.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Mechanism of the Preparation of High-Purity Indium by Electrodeposition

Hou

Wang

et al. 2022

Front. Chem.

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Indium is a crucial material and is widely used in high-tech industries, and electrodeposition is an efficient method to recover rare metal resources. In this work, the electrochemical behavior of In3+ was investigated by using different electrochemical methods in electrolytes containing sodium and indium sulfate. Cyclic voltammetry (CV), chronoamperometry (CA), and alternating current impedance (EIS) techniques were used to investigate the reduction reaction of In3+ and the electrocrystallization mechanism of indium in the indium sulfate system. The cyclic voltammetry results showed that the electrodeposition process is irreversible. The average charge transfer coefficient a of In3+ was calculated to be 0.116 from the relationship between the cathodic peak potential and the half-peak potential, and the H+ discharge occurred at a higher negative potential of In3+. The nucleation mechanism of indium electrodeposition was analyzed by chronoamperometry. The mechanism of indium at potential steps of −0.3 to −0.6 V was close to diffusion-controlled instantaneous nucleation with a diffusion coefficient of 7.31 × 10−9 cm2 s−1. The EIS results demonstrated that the reduction process of In3+ is subject to a diffusion-controlled step when pH = 2.5 and the applied potential was −0.5 V. SEM and XRD techniques indicated that the cathodic products deposited on the titanium electrode have excellent cleanliness and purity.

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“…Chemical purification of selenium, such as oxidative volatilization and H 2 Se thermal decomposition, converts elemental selenium Se into compounds containing Se 4+ , Se 6+ or Se 2− through oxidation or reduction. Then, according to their differences in physical and chemical properties, volatilization, selective precipitation, coordinated extraction, ion exchange and other methods are used to separate impurities from selenium [16][17][18][19][20][21][22]. Finally, after reduction or oxidation, Se 4+ , Se 6+ or Se 2− is converted into elemental selenium, and after repeated purification, high-quality selenium that meets the quality requirements is obtained.…”

Section: Introductionmentioning

confidence: 99%

A clean and efficient method for purifying crude selenium based on a selective leaching - directed decomposition purification process

et al. 2022

Mater. Res. Express

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The rare element selenium is a key material in supporting the development of high-tech and new products. This research has led to the development of a method of purifying crude selenium based on a selective leaching-directed decomposition purification process. The influence of factors such as the concentration of the leaching solution, leaching temperature, solid-liquid ratio, and leaching time on the leaching rate of Se were investigated in detail. The experimental results show that the optimal conditions for selective leaching of selenium were as follows: the concentration of leaching solution (solute: Na2SO3) was 260 g/L, the stirring speed was 300 rpm, the ratio of liquid to solid was 0.10 g/mL, the reaction temperature was 90 °C, the reaction time was 180 min, and the leaching rate of selenium on one run was > 95%. The products of selenium after two runs meet the requirements of Se99.9 in YS/223-2007, the Chinese nonferrous metal industry standard. The direct yield of Se is greater than 90%, and precious metals such as gold, silver and platinum are enriched in the residue. No waste is produced during the whole purification process, and all products can be recycled. This study provides an efficient and environmentally friendly method for the purification of crude selenium, which has important industrial applications.

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Removal of impurity Pb during crude selenium purification by controlling potential oxidation and vacuum distillation

Cited by 12 publications

References 16 publications

Combined Sulfidation and Vacuum Distillation for the Directional Removal of Hazardous Mercury from Crude Selenium

Combined Sulfidation and Vacuum Distillation for the Directional Removal of Hazardous Mercury from Crude Selenium

Electrochemical Mechanism of the Preparation of High-Purity Indium by Electrodeposition

A clean and efficient method for purifying crude selenium based on a selective leaching - directed decomposition purification process

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