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Preparation method for producing anhydrous sodium sulfate with 2,7-dihydroxy naphthalene mother liquid

A technology of anhydrous sodium sulfate, hydroxynaphthalene mother liquor, applied in chemical instruments and methods, alkali metal sulfite/sulfite, inorganic chemistry and other directions, can solve problems such as unfavorable industrialized production, difficult operation, large amount of waste water, etc. Easy industrialized mass production, no secondary pollution, less investment

Active Publication Date: 2014-04-16
ZAOZHUANG TAIRUI FINE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

According to the above production of anhydrous sodium sulfate, the cost of its synthetic method is too high, difficult to operate, and produces a large amount of waste water, which is not conducive to industrial production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0013] Step 1: 4000 kg of 2,7-dihydroxynaphthalene mother liquor was adjusted to pH 2 with 10 kg of 98% sulfuric acid, and 20 kg of activated carbon was added to filter at 50°C;

[0014] Step 2: the filtrate is cooled to 10°C, and centrifuged to obtain 1700 kg of sodium sulfate decahydrate;

[0015] Step 3, raising the temperature of the sodium sulfate decahydrate to 90°C, then cooling to 80°C and centrifuging to obtain 430 kg of anhydrous sodium sulfate;

[0016] Step 4: Add 5 kg of sodium hydroxide to the above centrifuged mother liquor to adjust the pH value to 9, add 20 kg of activated carbon and filter at 75°C;

[0017] Step 5: The filtrate is heated and concentrated, concentrated to two-thirds of the remaining filtrate, and centrifuged at 80°C to obtain 270 kg of anhydrous sodium sulfate;

[0018] Step 6: After cooling the mother liquor obtained after centrifugation to 10°C, centrifuge again to obtain sodium sulfate decahydrate, which is recycled to step 2 for continued...

example 2

[0020] Step 1: 4300 kg of 2,7-dihydroxynaphthalene mother liquor is adjusted to pH 2 with 13 kg of 98% sulfuric acid, and 20 kg of activated carbon is added to filter at 50°C;

[0021] Step 2: the filtrate is cooled to 10°C, and centrifuged to obtain 1900 kg of sodium sulfate decahydrate;

[0022] Step 3, raising the temperature of the sodium sulfate decahydrate to 90°C, then cooling to 80°C and centrifuging to obtain 480 kg of anhydrous sodium sulfate;

[0023] Step 4: Add 6 kg of sodium hydroxide to the above centrifuged mother liquor to adjust the pH value to 9, add 20 kg of activated carbon and filter at 78°C;

[0024] Step 5: The filtrate is heated and concentrated, concentrated to two-thirds of the remaining filtrate, and centrifuged at a temperature of 80°C to obtain 290 kg of anhydrous sodium sulfate;

[0025] Step 6: After cooling the mother liquor obtained after centrifugation to 10°C, centrifuge again to obtain sodium sulfate decahydrate, which is recycled to step ...

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Abstract

The invention discloses a preparation method for producing anhydrous sodium sulfate with 2,7-dihydroxy naphthalene mother liquid. The preparation method comprises the following steps: adjusting the pH value of 4000 to 4300 kilograms of 2,7-dihydroxy naphthalene mother liquid to 2 with 10-13 kilograms of 98% sulfuric acid; adding 20 kilograms of activated charcoal for filtering at the temperature of 50 DEG C; lowering the temperature of the filtrate to 10 DEG C, and centrifuging to obtain 1700-1900 kilograms of sodium sulfate decahydrate; raising the temperature of the sodium sulfate decahydrate to 90 DEG C, then lowering the temperature to 80 DEG C, and centrifuging to obtain 430-480 kilograms of anhydrous sodium sulfate; adding 5-6 kilograms of sodium hydroxide into the centrifuged mother liquid to adjust the pH value to 9; adding 20 kilograms of activated charcoal for filtering at the temperature of 75 DEG C-78 DEG C; raising the temperature of the filtrate and concentrating the filtrate to enable the concentrated amount of the filtrate to be two third of the residual filtrate; centrifuging at the temperature of 80 DEG C to obtain 270-290 kilograms of anhydrous sodium sulfate; lowering the temperature of the centrifuged mother liquid to 10 DEG C, and re-centrifuging to obtain sodium sulfate decahydrate. The preparation method is simple in technology, low in cost, and pollution-free.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular to a preparation method for producing anhydrous sodium sulfate by using 2,7-dihydroxynaphthalene mother liquor. Background technique [0002] In the prior art, the production of industrial anhydrous sodium sulfate mainly takes natural mirabilite ore as raw material's total solution evaporation dehydration method and takes saline lake brine as raw material to produce industrial anhydrous sodium sulfate at present. The raw materials are different, but most of the production methods adopt a two-step process. The first step is to precipitate thenardite or double salt containing sodium sulfate, and the second step is to process the selected thenardite into finished products. Produce anhydrous sodium sulfate according to above, its synthetic method cost is too high, is difficult for operation, and produces a large amount of waste water, is unfavorable for suitability for industrialized pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01D5/00
Inventor 杨玉栋周志辉卢海伟赵明侠
Owner ZAOZHUANG TAIRUI FINE CHEM
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