Method for producing industrial-grade ammonium dimolybdate by combination method

An ammonium dimolybdate, industrial-grade technology, applied in chemical instruments and methods, molybdenum compounds, inorganic chemistry, etc., can solve the problems of high impurity content and can not meet the national first-class standard, etc., and achieves high comprehensive recovery rate and equipment requirements. Low, short production cycle effect

Inactive Publication Date: 2011-04-13
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

At present, the industrial preparation of ammonium dimolybdate mainly adopts the method of dissolving ammonium polymolybdate in ammonia water and recrystallizing, while the ammonium dimolybdate produced by evaporation crystallization and acid precipitation method has high impurity content, which cannot reach the national standard level standard

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] (1) Take 1000g of ammonium tetramolybdate, the technical conditions meet the national first-class standard, and the molybdenum content is 55.8%; add ammonium tetramolybdate (kg): pure water (L): 25~28% concentrated ammonia water (L)= 1.00:0.60:1.00, the control temperature is 50°C, the reaction is 2h, and the stirring speed is 80r / min. After the reaction, a large amount of ammonium dimolybdate crystals are precipitated in the solution.

[0018] (2) After continuing to age and cool the ammonia solution obtained above for 1 hour, filter and separate the crystallization mother liquor;

[0019] (3) Add nitric acid to the crystallization mother liquor obtained above to pH=2.0, control the temperature at 40°C, and precipitate ammonium polymolybdate;

[0020] (4) reclaim polyammonium molybdate from crystallization mother liquor according to prior art;

[0021] (5) Drying treatment of ammonium dimolybdate and ammonium polymolybdate.

[0022] A. According to the prior art, the...

Embodiment 2

[0025] (1) Take 1000g of ammonium tetramolybdate, the technical conditions meet the national first-class standard, and the molybdenum content is 55.8%; add ammonium tetramolybdate (kg): pure water (L): 25~28% concentrated ammonia water (L)= 1.00:0.80:1.00, the control temperature is 70°C, the reaction is 3h, the stirring speed is 100r / min, after the reaction, a large amount of ammonium dimolybdate crystals are precipitated in the solution.

[0026] (2) After continuing to age and cool the ammonia solution obtained above for 2 hours, filter and separate the crystallization mother liquor;

[0027] (3) Add nitric acid to the crystallization mother liquor obtained above to pH=1.5, control the temperature at 50°C, and precipitate ammonium polymolybdate;

[0028] (4) reclaim polyammonium molybdate from crystallization mother liquor according to prior art;

[0029] (5) Drying treatment of ammonium dimolybdate and ammonium polymolybdate.

[0030] A. According to the prior art, the a...

Embodiment 3

[0033] (1) Take 1000g of ammonium tetramolybdate, the technical conditions meet the national first-class standard, and the molybdenum content is 55.8%; add ammonium tetramolybdate (kg): pure water (L): 25~28% concentrated ammonia water (L)= 1.00:1.00:1.20, the control temperature is 75°C, the reaction is 3h, the stirring speed is 120r / min, after the reaction, a large amount of ammonium dimolybdate crystals are precipitated in the solution.

[0034] (2) After continuing to age and cool the ammonia solution obtained above for 3 hours, filter and separate the crystallization mother liquor;

[0035] (3) Add nitric acid to the crystallization mother liquor obtained above to pH=2.5, control the temperature at 50°C, and precipitate ammonium polymolybdate;

[0036] (4) reclaim polyammonium molybdate from crystallization mother liquor according to prior art;

[0037] (5) Drying treatment of ammonium dimolybdate and ammonium polymolybdate.

[0038] A. According to the prior art, the a...

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Abstract

The invention relates to a method for producing industrial-grade ammonium dimolybdate by a combination method. The method comprises the following steps: adding pure water and ammonia water into industrial ammonium molybdate which is taken as a raw material, dissolving ammonium and evaporating, aging and crystallizing to separate out ammonium dimolybdate, wherein the crystallization rate is more than 87%; and separating solid from liquid for crystallization mother liquor, and carrying out acid precipitation to obtain ammonium polymolybdate, wherein the comprehensive recovery of molybdenum can be up to more than 99%. By using the invention, the purity of the ammonium dimolybdate is greatly improved, the product quality can reach the national level, the operation is simple and convenient, and the equipment is simple, therefore, the method has very good application value.

Description

technical field [0001] The invention relates to a method for producing industrial-grade ammonium dimolybdate by a combined method. Background technique [0002] Ammonium dimolybdate can be used to prepare molybdenum trioxide and molybdenum powder, and then can be processed into molybdenum bar, molybdenum electrode, molybdenum slab, molybdenum wire, molybdenum foil and other molybdenum alloy products, which are widely used in steel, cermet, electric light source, metallurgy , Aerospace and military industries and other fields. At present, the industrial preparation of ammonium dimolybdate mainly adopts the method of dissolving ammonium polymolybdate in ammonia water and recrystallizing, while the ammonium dimolybdate produced by evaporation crystallization and acid precipitation method has high impurity content, which cannot reach the national standard level standard. Contents of the invention [0003] The object of the present invention is to provide a kind of combined m...

Claims

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Application Information

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IPC IPC(8): C01G39/00
CPCC01G39/00
Inventor 张宝李倩夏晓梅彭春丽张佳峰沈超陈核章
Owner CENT SOUTH UNIV
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