A method for catalytic reduction of selenium

A reducing agent and catalyst technology, which is applied in the field of reducing hexavalent selenium to elemental selenium, and achieves the effects of good effect, short reaction process and reduced descending speed

Active Publication Date: 2017-02-08
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The method is simple and convenient to operate, has high industrial feasibility, and effectively solves the technical problems in the existing selenium production process

Method used

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  • A method for catalytic reduction of selenium
  • A method for catalytic reduction of selenium

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Effect test

Embodiment 1

[0026] A kind of method of catalytic reduction selenium of the present invention, concrete steps are as follows:

[0027] Sodium selenate (Na 2 SeO 4 ) is dissolved in ultrapure water and is prepared into a sodium selenate solution, so that the selenium content in the solution is 1g / L, and the initial pH of the solution is 2, and 100mL of the solution is taken, and 15mL of analytically pure hydrogen peroxide is added with a constant flow pump, and after mixing evenly, feed Industrial-grade sulfur dioxide gas (gas flow rate is 1L / min), while using a water bath to control the temperature of the reaction system is 60 ° C, reacted for 2 hours, filtered and detected the remaining selenium content in the solution, the final selenium reduction rate was 99.97%, and the reduced solid product was carried out X-ray diffraction detection (such as figure 1 shown), scanning electron microscope detection and inductively coupled plasma atomic emission spectrometry detection results (see Tab...

Embodiment 2

[0029] A kind of method of catalytic reduction selenium of the present invention, concrete steps are as follows:

[0030] Sodium selenate (Na 2 SeO 4 ) is dissolved in ultrapure water and prepared as a sodium selenate solution, making the selenium content 1g / L, adjusting the initial pH of the solution=2, taking 100mL of the solution, adding 15mL of analytically pure hydrogen peroxide with a constant flow pump, and feeding into industrial grade sulfur dioxide after mixing Gas (the gas flow rate is 1L / min), while using an ice-water bath to control the temperature of the reaction system to be 0°C, react for 2 hours, detect the remaining selenium content in the solution after filtration, calculate the selenium reduction rate to be 99.89%, and carry out X-ray diffraction on the solid product detection (such as figure 2 shown), scanning electron microscope detection and inductively coupled plasma atomic emission spectrometry detection results (see Table 1), as can be seen from Ta...

Embodiment 3

[0032] A kind of method of catalytic reduction selenium of the present invention, concrete steps are as follows:

[0033] Take 1L of wastewater containing hexavalent selenium from a smelter, in which the concentration of selenium is 5.5g / L, and other impurities include arsenic ions, sodium ions, chromium ions and organic matter. After adding excess hydrogen peroxide 500mL to decompose impurities such as organic matter therein, add 30g of sodium sulfite, control the temperature in a water bath at 50°C, react for 2 hours and then filter, detect the remaining selenium content in the solution, and calculate the selenium reduction rate to be 97.87%. The X-ray detection result of selenium element is the same as that of Example 1, and the detection result of inductively coupled plasma atomic emission spectrometry is shown in Table 1.

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Abstract

Provided is a method for catalytically reducing selenium. Hydrogen peroxide is used as a catalyst, and a reducer is added to a hexavalent-selenium-containing solution for reaction so as to reduce the selenium to elemental selenium, wherein the standard oxidation-reduction potential of the reducer is lower than the standard oxidation-reduction potential of the conversion of the hexavalent selenium to elemental selenium. The present method can further reduce a hexavalent-selenium element-containing selenic acid or selenate solution to an elemental selenium product in one step. In the present method, the hydrogen peroxide effectively lowers the descending speed of the reduction potential of the solution while having a catalytic effect, so that the reduction reaction process is carried out gently, thereby effectively preventing the selenium in the solution from overreducing to generate negatively bivalent selenium ions or compounds thereof, and solving problems such as a low recovery rate caused by selenium overreduction.

Description

technical field [0001] The invention relates to a method for catalytically reducing selenium, in particular to a method for reducing hexavalent selenium into elemental selenium. Background technique [0002] Selenium is a typical element between metals and non-metals. It is widely used in glass and dyeing industries. It is irreplaceable in optimizing glass performance and preparing high-temperature resistant pure red dyes. In the field of materials, different proportions of selenium Adding steel, copper, rubber, etc. can significantly improve its oxidation resistance, mechanical properties and wear resistance; the most important development field of selenium is the optoelectronic industry. These unique characteristics have brought about its huge utilization value and demand. [0003] At present, the recovery of industrial selenium is mainly concentrated in the field of hydrometallurgy, which is mainly extracted and prepared from the traditional process of steaming selenium-...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B19/02
CPCC01B19/02C01P2002/72C01P2006/80C01B15/01C01P2002/70
Inventor 郭学益徐润泽李栋田庆华
Owner CENT SOUTH UNIV
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