Preparation method for high-purity ammonium paratungstate

A pure ammonium paratungstate, ammonium tungstate technology, applied in chemical instruments and methods, tungsten compounds, inorganic chemistry and other directions, can solve the problems of low conversion rate, poor effect, low concentration of ammonium tungstate solution, etc., to reduce production costs, The effect of improving the recovery rate

Active Publication Date: 2012-09-19
JIANGXI XINSHENG TUNGSTEN IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are two problems in this method: one is that the effect of APT ammonia dissolution is not good, the conversion rate of APT dissolution process is low, and the concentration of the obtained ammonium tungstate solution is also low; the other is that low-quality APT cannot effectively remove impurities without calcination, which affects the final Quality of APT products
[0017] With the continuous development of the tungsten industry, the ammonium paratungstate products produced by the existing ion exchange and extraction methods are increasingly unable to meet the needs of the production of high-quality tungsten deep-processing products

Method used

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  • Preparation method for high-purity ammonium paratungstate
  • Preparation method for high-purity ammonium paratungstate
  • Preparation method for high-purity ammonium paratungstate

Examples

Experimental program
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Effect test

Embodiment 1

[0038] 1. The process of APT calcining to generate tungsten trioxide. Put the APT into the feeding bin, send the APT into the rotary furnace at a constant speed through the screw feeder, control the temperature and atmosphere in the rotary furnace, the feed rate is 150kg / h, and the calcination temperature is 550°C for the first zone and 640°C for the second zone. Three bands 680°C. After being calcined in a rotary furnace, the conversion rate of APT into tungsten trioxide reaches 98.85%.

[0039] 2. During the dissolving process of ammonium tungsten trioxide, the temperature of 150g / l ammonia solution is controlled at 95°C, the liquid-solid ratio is controlled at 3:1ml / g, and tungsten trioxide is added while stirring, and the reaction time is 1.5h to obtain ammonium tungstate solution. and filter.

[0040] 3. After the ammonium tungstate solution is filtered, it is measured into the evaporative crystallization pot for evaporative crystallization, and the evaporative crystall...

Embodiment 2

[0043]1. The process of APT calcining to generate tungsten trioxide. Put the APT into the feed bin, send the APT into the rotary furnace at a constant speed through the screw feeder, control the temperature and atmosphere in the rotary furnace, the feed rate is 160kg / h, and the calcination temperature is 560°C in the first zone and 650 in the second zone. ℃, three bands 690 ℃. After being calcined in a rotary furnace, the conversion rate of APT into tungsten trioxide reaches 99.05%.

[0044] 2. The ammonia tungsten trioxide dissolution process, the concentration of 70g / l ammonia solution is controlled at 100°C, the liquid-solid ratio is controlled at 4:1ml / g, adding tungsten trioxide, stirring, and the reaction time is 2 hours to obtain ammonium tungstate solution, and filtered.

[0045] 3. After the ammonium tungstate solution is filtered, it is measured into the evaporative crystallization pot for evaporative crystallization, and the evaporative crystallization steam is co...

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Abstract

The invention relates to a preparation method for high-purity ammonium paratungstate. The preparation method is characterized in that: raw materials are prepared, namely APT (ammonium paratungstate) which is produced by an ion exchange method or an extraction method, has the impurity total content less than or equal to 177.5 ppm and confirms to national standard of 0 level or unqualified APT which is produced in the production process and has the impurity total content more than or equal 177.5 ppm are prepared. The method comprises the following steps of: calcining the prepared raw materials to produce tungsten trioxide; dissolving the produced tungsten trioxide by using ammonia to produce ammonium tungstate solution; performing evaporative crystallization on the produced ammonium tungstate solution to obtain wet ammonium paratungstate crystals; and drying and screening the wet ammonium paratungstate crystals so as to obtain the high-purity ammonium paratungstate of which the impurity total content is less than or equal to 65 ppm. According to the extraction method, a production process of the high-purity APT is optimized, the product quality is improved, and the production cost of the high-purity APT products is reduced.

Description

technical field [0001] The invention relates to a preparation method of high-purity ammonium paratungstate. [0002] In this patent specification, the term "ammonium paratungstate" is also referred to as APT for short. [0003] In this patent specification, the term "APT raw material" refers to the national standard zero-grade product APT. [0004] In this patent specification, the term "nonconforming APT" is a common name for APT waste, dirty material, and APT products with various impurities exceeding the standard. [0005] In this patent specification, the term "high-purity ammonium paratungstate" refers to ammonium paratungstate whose total amount of impurities can be controlled within ≤65ppm, that is, high-purity ammonium paratungstate with low impurity content. . [0006] In this patent specification, the term "preparation of raw materials" refers to the APT produced by the ion exchange method or extraction method that reaches the national standard 0 (total impurity c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01G41/00
Inventor 谢金明王光明罗章青唐美春彭文
Owner JIANGXI XINSHENG TUNGSTEN IND
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