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Method for producing anhydrous Na2SO3 by using alkali-containing waste mother liquor

A technology of waste mother liquor and na2so3, applied in the field of production of anhydrous sodium sulfite, can solve the problems of unsolved waste alkali water pollution, short production process, low cost, etc., and achieves high sales added value, small investment and low energy consumption. Effect

Inactive Publication Date: 2013-01-23
TIANJIN ZHONGKE CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The production process is short, low energy consumption and low cost; the absorption and reaction crystallization system adopts a fully closed cycle operation, no waste water and waste residue; suitable for various industrial kilns and coal-fired boilers in metallurgy, steel, petrochemical, pharmaceutical and other industries SO 2 Exhaust gas treatment can realize the SO2 contained in various kilns 2 Recycling of waste gas, although for waste gas SO 2 Recycling was carried out, but the pollution problem of waste alkaline water was not solved

Method used

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  • Method for producing anhydrous Na2SO3 by using alkali-containing waste mother liquor

Examples

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Effect test

Embodiment 1

[0034] The main components of the heavy soda ash waste liquid produced by the soda ash factory used in the present invention are: sodium chloride: 60-75 g L -1 , sodium carbonate: 230-260 g·L -1 . The method and technological process of producing anhydrous sodium sulfite are as follows:

[0035] (1) Initial treatment of heavy soda ash waste mother liquor: use a filter press to filter, give a pressure of 100-120kpa, filter out impurities in heavy soda ash waste mother liquor, and then prepare a concentration of 18-22 degrees Baume The solution;

[0036](2) Generation of sulfur dioxide and water washing: Air is blown into the sulfur furnace by a Roots blower, and the sulfur is burned in the sulfur furnace. Sulfur is oxidized and then enters the absorption tower. The liquid obtained after washing sulfur dioxide with water, after filtration, the obtained filtrate is added to magnesium oxide to form magnesium sulfate cold crystallization, which is used as a flocculant for indus...

Embodiment 2

[0046] The specific method, process flow and recycling approach of this embodiment are basically the same as those in Example 1, the difference being step (4), step (5), and step (7), as follows:

[0047] (4) Neutralization: pump the mixed mother liquor of sodium sulfite and sodium bisulfite into the neutralization tank, add ion-exchange membrane liquid caustic soda at 100°C-120°C to neutralize until the pH value is 8, and make the mixed mother liquor completely generate sodium sulfite;

[0048] (5) Adjust the pH value: put the neutralized sodium sulfite and sodium bisulfite mixed mother liquor into the pH adjustment tank, add liquid alkali to adjust the pH value to 12;

[0049] (7) Evaporate the mother liquor until the mass fraction of crystals is 38-39%, and when the crystallization temperature is 120°C, keep it for 3-4 hours to obtain sodium sulfite crystals;

[0050] After testing, the high-grade anhydrous sodium sulfite produced accounted for 20%, and the first-grade anhy...

Embodiment 3

[0052] The specific method and process flow of this embodiment are basically the same as those of Embodiment 1, the difference lies in step (4) and step (5), as follows:

[0053] Step (4) and step (5) are combined into one step: pump the mixed mother liquor of sodium sulfite and sodium bisulfite into the neutralization tank, and add ion membrane liquid caustic soda at 100°C-120°C until the pH value is greater than 12;

[0054] After testing, the anhydrous sodium sulfite produced is all qualified.

[0055] The above-mentioned methods and technological process are similar in the treatment of alkali-containing waste liquid or waste gas desulfurization. It is used in the purification of waste lye produced in the production process of other chemical products, and is also applicable to the desulfurization of sulfur dioxide-containing gas discharged from high-sulfur coal and pyrite. The technological process and method steps of the purification treatment are basically the same, but ...

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Abstract

The invention provides a method for producing anhydrous Na2SO3 by using waste mother liquor generated in the production process of soda ash dense. The method is characterized by comprising the following steps of: performing primary treatment on alkali-containing waste mother liquor; generating sulfur dioxide and washing with water; absorbing sulfur dioxide by the alkali-containing waste mother liquor which is subjected to the primary treatment; adding alkali to adjust pH value to be 8 to 14 at high temperature; standing, filter-pressing and decolorizing, and removing residues; performing vacuum concentration and evaporation on a saturated sodium sulfite solution from which the residues are removed; and performing centrifugal dewatering on sodium sulfite crystal substances and drying; and detecting the dried anhydrous sodium sulfite, metering, packaging and putting in storage. The alkali-containing waste mother liquor is used as a raw material, and the waste mother liquor absorbs sulfur dioxide so as to prepare the anhydrous sodium sulfite; therefore, the alkali-containing waste mother liquor can be purified completely; the whole process is simple, low in investment, low in energy consumption, and easy to popularize and apply, and has obvious social and economic benefits; and wastes and secondary pollution can be avoided.

Description

technical field [0001] The invention belongs to the technology of purification, treatment and reuse of chemical wastewater, in particular to a method for producing anhydrous sodium sulfite. Background technique [0002] Since entering the 21st century, my country is carrying the most unprecedented resource consumption and economic activities with the most fragile ecological environment in history, and is facing the most prominent ecological environment challenge in history. The contradictions between population and resources, economic development and ecological environment have become the biggest constraints on China's modernization development. The waste gas and alkali-containing wastewater released by factories are two kinds of pollutants that are relatively harmful to the natural ecological environment and human health. To maintain sustainable development, it is necessary to reduce environmental pollution. SO 2 Is the main one in the exhaust gas, for SO 2 The tradition...

Claims

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Application Information

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IPC IPC(8): C01D5/14
Inventor 卢俊锋张兆军
Owner TIANJIN ZHONGKE CHEM
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