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Method for producing sodium nitrate by utilizing wastewater discharged during nuclear grade zirconium dioxide production

A technology of zirconium dioxide and sodium nitrate, applied in chemical instruments and methods, alkali metal nitrates, inorganic chemistry, etc., can solve problems such as difficulty in reflecting social and economic benefits, large waste of resources, high acidity, etc., and achieve obvious social benefits The effect of benefit and economic benefit, full utilization of resources, and simple process flow

Active Publication Date: 2018-04-20
中核二七二铀业有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The above two acidic waste liquids contain zirconium, hafnium and other metal cations, 2.5-4.5 mol / L of nitric acid, need to add lime milk for neutralization to pH 6-9 before being discharged, due to the large amount of waste liquid and high acidity, neutralization treatment The cost is high, and the nitric acid in the waste liquid cannot be effectively recycled; the alkaline waste liquid contains sodium nitrate, and the waste of direct discharge of resources is large, and it is difficult to reflect its social and economic benefits

Method used

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  • Method for producing sodium nitrate by utilizing wastewater discharged during nuclear grade zirconium dioxide production

Examples

Experimental program
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Effect test

Embodiment 1

[0021] (1), the 1m produced by the separation of zirconium and hafnium during the production of nuclear grade zirconia 3 The remaining water from the acidification of the organic phase is transported to the neutralization tank with a pump, and the concentration of nitric acid is 3.5mol / L for sampling and analysis; neutralization is carried out in the neutralization tank with 20% liquid caustic soda at room temperature, and the final pH value is controlled to be 8. Filtration, wet filter residue 0.78kg, filtrate 1.6m 3 , the concentration of sodium nitrate in the filtrate is 15.62%, which can be used as raw material for sodium nitrate production.

[0022] (2), the 1m produced after the extraction and enrichment of hafnium 3 The raffinate is transported to the neutralization tank with a pump, and the concentration of nitric acid is 2.5mol / L for sampling and analysis; it is neutralized with 20% liquid caustic soda at room temperature in the neutralization tank, and the final pH ...

Embodiment 2

[0026] 1), the 1m produced by the separation of zirconium and hafnium during the production of nuclear grade zirconium dioxide 3 The remaining water from the acidification of the organic phase is transported to the neutralization tank with a pump, and the concentration of nitric acid is 4.0mol / L for sampling and analysis; it is neutralized with 20% liquid caustic soda at room temperature in the neutralization tank, and the pH at the end point is controlled to be 8.5. Filter to get wet filter residue 0.95kg, filtrate 1.68m 3 , the concentration of sodium nitrate in the filtrate is 18.35%, which can be used as raw material for sodium nitrate production.

[0027] (2), the 1m produced after the extraction and enrichment of hafnium 3 The raffinate is transported to the neutralization tank with a pump, and the concentration of nitric acid is 4mol / L for sampling analysis; neutralization is carried out at normal temperature in the neutralization tank with 20% liquid caustic soda, the...

Embodiment 3

[0031] 1), the 1m produced by the separation of zirconium and hafnium during the production of nuclear grade zirconium dioxide 3 The remaining water from the acidification of the organic phase is transported to the neutralization tank with a pump, and the concentration of nitric acid is 4.5mol / L for sampling and analysis; it is neutralized with 20% liquid caustic soda at room temperature in the neutralization tank, and the pH at the end point is controlled to be 8.3. Filtration, wet filter residue 0.78kg, filtrate 1.71m 3 , the analysis filtrate sodium nitrate concentration 18.15%, can be used as the raw material of sodium nitrate production.

[0032] (2), the 1m produced after the extraction and enrichment of hafnium 3 The raffinate is transported to the neutralization tank with a pump, and the concentration of nitric acid is 4.5mol / L for sampling analysis; neutralization is carried out with 20% liquid caustic soda at room temperature in the neutralization tank, and the fina...

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Abstract

The invention provides a method for producing sodium nitrate by utilizing wastewater discharged during nuclear grade zirconium dioxide production. The method specifically comprises the following steps: neutralizing organic phase acidized remained water produced in a zirconium and hafnium separation process and raffinate produced after hafnium extraction and enrichment in the nuclear grade zirconium dioxide production process with caustic soda, filtering to remove solid precipitating particles, and taking the obtained filtrate and precipitated waste liquid produced in the zirconium oxide preparation process as feed liquid for producing the sodium nitrate; and evaporating and concentrating the feed liquid in an evaporator, crystallizing the concentrated solution in a flash crystallizer, filtering crystal mush by a centrifugal machine, thereby obtaining the sodium nitrate. The method disclosed by the invention is simple in process flow, full in resource utilization and low in cost, reaches waste liquid reduction of 90% or higher, realizes environment friendliness and has obvious social benefits and economic benefits.

Description

technical field [0001] The invention belongs to the field of extraction and separation, and in particular relates to a method for producing sodium nitrate by using nuclear-grade zirconium dioxide production discharge wastewater. Background technique [0002] The separation of zirconium and hafnium is a key step in the production process of nuclear grade zirconium dioxide. Under the mononitric acid system, tributyl phosphate is used as extractant and sulfonated kerosene is used as diluent to form an organic phase for extraction and separation of zirconium and hafnium. Before entering the extraction system, the organic phase needs to be acidified with 6mol / L dilute nitric acid solution, i.e. acidifying agent, part of the aqueous solution produced after acidification is returned to the extraction system to prepare acidifying agent, and part of it is treated as acidic waste liquid; the extraction and separation of zirconium and hafnium The raffinate is used as the original solu...

Claims

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Application Information

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IPC IPC(8): C01D9/00
CPCC01D9/00C01P2006/82
Inventor 孔冬成钟华围王育学祝和彪呼强辉
Owner 中核二七二铀业有限责任公司