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Method for producing sodium selenite

A technology of sodium selenite and its production method, applied in chemical instruments and methods, selenium/tellurium compounds, inorganic chemistry, etc., can solve problems such as environmental pollution and poisoning, serious equipment corrosion, long production cycle, etc., and achieve low production cost , small equipment investment and simple production process

Active Publication Date: 2011-05-18
广东先导稀贵金属材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process equipment is seriously corroded, the production cycle is long, and the cost is high; moreover, the intermediate product selenium dioxide is a highly toxic substance, which is likely to cause environmental pollution and poisoning incidents

Method used

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  • Method for producing sodium selenite
  • Method for producing sodium selenite

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A kind of sodium selenite production method, preparation process is as follows:

[0028] (1) Grinding elemental selenium into selenium powder by a mill and sieving;

[0029] (2) Water is added in the autoclave, open the reactor stirring paddle, then add solid sodium hydroxide by 152g / L in the kettle with a vacuum feeder to prepare aqueous sodium hydroxide solution (calculation method here is (150 / 78.9) × 2 × 40. Because the molar ratio of sodium hydroxide and selenium powder is 2: 1);

[0030] (3) Reactor is heated to 100 DEG C of insulation, and selenium powder is slowly dropped into reactor under agitation, and the control selenium concentration is 150g / L;

[0031] (4) Introduce high-pressure oxygen, and react at constant temperature and pressure for 10 hours at an oxygen pressure of 2.0 MPa and a temperature of 100° C.;

[0032] (5) Weigh 0.4kg of activated carbon adsorbent and add it to the reaction kettle, stir evenly, and cool down to ≤70°C after stirring for 2...

Embodiment 2

[0036] A kind of sodium selenite production method, preparation process is as follows:

[0037] (1) Grinding elemental selenium into selenium powder by a mill and sieving;

[0038] (2) water is added in the autoclave, open the reactor stirring paddle, then add solid sodium hydroxide by 202.8g / L in the kettle to prepare aqueous sodium hydroxide solution (calculation method is (200 / 78.9) ) × 2 × 40. Because the molar ratio of sodium hydroxide and selenium powder is 2: 1);

[0039] (3) Reactor is heated to 150 ℃ of insulation, and selenium powder is slowly dropped into the reactor under agitation, and the control selenium concentration is 200g / L;

[0040] (4) feed high-pressure oxygen, and react at constant temperature and pressure for 7 hours at an oxygen pressure of 1.5MPa and a temperature of 90°C;

[0041] (5) Weigh 1 kg of activated carbon adsorbent and add it to the reaction kettle, stir evenly, and cool down to ≤70°C after stirring for 3 hours;

[0042] (6) press filter...

Embodiment 3

[0045] A kind of sodium selenite production method, preparation process is as follows:

[0046] (1) Grinding elemental selenium into selenium powder by a mill and sieving;

[0047] (2) water is added in the autoclave, open the reactor stirring paddle, then add solid sodium hydroxide by 253.5g / L in the kettle with a vacuum feeder to prepare aqueous sodium hydroxide solution (calculation method here is (250 / 78.9) × 2 × 40. Because the mol ratio of sodium hydroxide and selenium powder is 2: 1);

[0048] (3) Reactor is heated to 200 ℃ insulation, selenium powder is slowly dropped into reactor under agitation, and the control selenium concentration is 250g / L;

[0049] (4) Feed high-pressure oxygen, and react at constant temperature and pressure for 14 hours at an oxygen pressure of 0.9MPa and a temperature of 140°C;

[0050] (5) Weigh 1.2kg of activated carbon adsorbent and add it to the reaction kettle, stir evenly, and cool down to ≤70°C after stirring for 5 hours;

[0051] (...

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Abstract

The invention discloses a method for producing sodium selenite, in particular a process for producing the sodium selenite through oxidation by taking elemental selenium as a raw material and introducing high-pressure oxygen into a sodium hydroxide water solution. The production process of the sodium selenite comprises the following steps of: firstly, grinding the elemental selenium into selenium power by a mill; secondly, preparing the sodium hydroxide water solution in an autoclave; thirdly, feeding selenium powder into the autoclave; fourthly, introducing high-pressure oxygen and oxidizing at constant temperature and constant pressure; fifthly, adding a proper amount of adsorbent; sixthly, press filtering, heating and evaporating filtrate, condensing and crystallizing; and seventhly, heating, drying and crystallizing, crushing and screening to obtain the sodium selenite. The method has the advantages of simple production process, less investment for equipment, simpleness and convenience of operation, low energy consumption, low production cost and high purity of products and is a preparation method of the sodium selenite, which has the characteristics of high efficiency, energy saving, environmental protection and low cost.

Description

technical field [0001] The invention relates to a method for producing sodium selenite, in particular to a method for producing sodium selenite by introducing elemental selenium as a raw material and introducing oxygen into aqueous sodium hydroxide solution. Background technique [0002] Sodium selenite (Na 2 SeO 3 ) colorless crystal, stable in air, soluble in water and insoluble in alcohol. Hydrate is Na 2 SeO 3 ·5H 2 O, the surface is easy to weather and lose water in dry air, and it turns into anhydrous salt when heated to 40°C. Selenium and its compounds are highly toxic, but trace amounts of selenium are essential nutrients for the human body. In my country, sodium selenite is used to prevent and control the disease (an endemic disease) and has achieved remarkable results. It is also effective in preventing selenium deficiency diseases in livestock. Sodium selenite is one of the important products for supplementing selenium in livestock and poultry. It is used as...

Claims

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Application Information

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IPC IPC(8): C01B19/00
Inventor 朱世会朱世明朱刘
Owner 广东先导稀贵金属材料有限公司
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