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Method for deeply purifying ammonium tungstate solution

A deep purification and ammonium tungstate technology, applied in chemical instruments and methods, tungsten compounds, inorganic chemistry, etc., can solve the problems of excessive magnesium content and large wastewater discharge, achieve low reaction resistance, reduce ammonia consumption and production costs Effect

Pending Publication Date: 2019-12-13
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because the traditional tungsten ion exchange technology generally has a large amount of wastewater discharge, and the current national environmental protection policy is becoming increasingly stringent, under the new environmental protection situation, the traditional tungsten ion exchange technology has shown certain limitations.
[0005] 2) For the ammonium tungstate solution containing phosphorus, arsenic, and silicon impurities, when the ammonium magnesium salt precipitation method is used to remove phosphorus, arsenic, and silicon, that is, magnesium salt is added to the ammonium tungstate solution to form impurities that are difficult to form with phosphorus, arsenic, and silicon. The soluble compound is precipitated and removed, and the general Mg in the ammonium tungstate solution after impurity removal 2+ The residual concentration of the ammonium paratungstate can reach 0.04-0.15g / L, and the direct evaporation and crystallization of the ammonium tungstate solution after impurity removal will cause the magnesium content in the ammonium paratungstate product to exceed the standard
At the same time, the selective precipitation method can only reduce the molybdenum to a minimum of 0.005-0.01g / L, and there is nothing to do when it is necessary to further reduce the molybdenum concentration

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] This embodiment proposes a method for deep purification of ammonium tungstate solution, including steps:

[0033] Step 1. Vulcanization treatment

[0034] Take 1000mL of ammonium tungstate solution obtained by dissolving crude tungstate in ammonia and removing phosphorus, arsenic, silicon by ammonium magnesium salt precipitation and molybdenum by selective precipitation. It is measured that it contains WO 3 240g / L, Mo 0.05g / L, S 2- 0.5g / L, Cu 0.009g / L, P 0.008g / L, As 0.009g / L, Si 0.008g / L, Mg 0.054g / L, K 0.060g / L, Na 0.046g / L, NH 3 30g / L.

[0035] Add S to the above ammonium tungstate solution 2- 80g / L (NH 4 ) 2 S solution 18mL, heat preservation and vulcanization at 50°C for 2h to obtain a vulcanized ammonium tungstate solution.

[0036] Step 2. Precipitating calcium tungstate

[0037] Under stirring conditions, slowly add Ca(OH) to the ammonium tungstate solution after sulfidation in step 1 2 84g, then closed and stirred at 40°C for 60 minutes, then raise...

Embodiment 2

[0043] This embodiment proposes a method for deep purification of ammonium tungstate solution, including steps:

[0044] Step 1, vulcanization treatment:

[0045] Take 1000mL of ammonium tungstate solution obtained by dissolving crude tungstate in ammonia and removing phosphorus, arsenic, silicon by ammonium magnesium salt precipitation and molybdenum by selective precipitation, which contains WO 3 160g / L, Mo 0.016g / L, S 2- 1.6g / L, Cu 0.006g / L, P 0.010g / L, As 0.009g / L, Si 0.007g / L, Mg 0.034g / L, K 0.096g / L, Na 0.062g / L, NH 3 40g / L.

[0046] Add (NH 4 ) 2 S to solution S 2- 1.6g / L, stop adding, and then vulcanize at 30°C for 2 hours to obtain a vulcanized ammonium tungstate solution.

[0047] Step 2. Precipitating calcium tungstate:

[0048] Under the condition of stirring at 30°C, slowly add Ca(OH) to the ammonium tungstate solution after step 1 sulfidation 2 50g, stirred and reacted for 150min, filtered to obtain calcium tungstate precipitate and mother liquor; the ...

Embodiment 3

[0055] This embodiment proposes a method for deep purification of ammonium tungstate solution, including steps:

[0056] Step 1, vulcanization treatment:

[0057] Take 1000mL of ammonium tungstate solution obtained by dissolving crude tungstate in ammonia and removing phosphorus, arsenic, silicon by ammonium magnesium salt precipitation and molybdenum by selective precipitation, which contains WO 3 260g / L, Mo 0.028g / L, S 2- 0.8g / L, Cu 0.008g / L, P 0.004g / L, As 0.005g / L, Si 0.004g / L, Mg 0.058g / L, K 0.024g / L, Na 0.028g / L, NH 3 26g / L ammonium tungstate solution.

[0058] Add S to the above ammonium tungstate solution 2- 80g / L (NH 4 ) 2 S solution 15mL, vulcanized at 30°C for 3h to obtain sulfided ammonium tungstate solution.

[0059] Step 2. Precipitating calcium tungstate:

[0060] Under stirring conditions at 30°C, slowly add 88 g of CaO to the sulfided ammonium tungstate solution in Step 1, stir and react for 60 minutes, then filter to obtain calcium tungstate precip...

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Abstract

The invention discloses a method for deeply purifying ammonium tungstate solution. The method comprises the following steps: adding excessive (NH4)2S into a coarsely treated ammonium tungstate solution under a stirring condition until S2<-> reaches a set concentration, and then carrying out vulcanization reaction at a set temperature, so that molybdenum in the ammonium tungstate solution is converted into thiomolybdate ions (MoS42 <->) to obtain a vulcanized ammonium tungstate solution; adding a calcium agent into the vulcanized ammonium tungstate solution under a stirring condition, and thencarrying out stirring reaction under a set condition, so as to obtain calcium tungstate precipitate and a mother liquor containing ammonia water after the reaction is finished; adding the calcium tungstate precipitate into a hydrochloric acid solution at a set temperature under a stirring condition, carrying out heat preservation and stirring reaction, and filtering after the reaction is finished,so as to obtain refined tungstic acid and an acid decomposition mother liquor; cleaning the refined tungstic acid, putting the cleaned tungstic acid into ammonia water for ammonia dissolution, and filtering to obtain ammonia dissolution slag and an ammonium tungstate deep purification liquid.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a method for deeply purifying ammonium tungstate solution. Background technique [0002] In the tungsten metallurgical industry, tungstic acid is an important intermediate product. Tungstic acid is a kind of solid inorganic acid, which is easily soluble in alkaline aqueous solution. Crude tungstic acid generally refers to the solid tungstic acid obtained by decomposing scheelite or crude sodium tungstate with hydrochloric acid, nitric acid and other inorganic acids. It is a common production raw material in tungsten metallurgy. , silicon, molybdenum and other impurities are relatively high, and qualified ammonium tungstate products can only be produced after further impurity removal. [0003] In order to produce ammonium paratungstate products from crude tungstic acid, it is often used The technical process, but the technical process has the following problems: [0004] 1) ...

Claims

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Application Information

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IPC IPC(8): C01G41/00
CPCC01G41/00
Inventor 霍广生曾璐琦
Owner CENT SOUTH UNIV
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