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Method for extracting high-purity ammonium thiocyanate and ammonium sulphate from coking desulfurization/decyanation waste liquor

A technology of ammonium thiocyanate and coking desulfurization, which is applied in the direction of thiocyanate and ammonium sulfate, can solve the problems of cost increase and complicated process, and achieve the effects of convenient operation, simple extraction method, and reduction of emissions and environmental pollution

Inactive Publication Date: 2013-03-20
BEIJING RISUN TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But this method needs to add new salt or acid, resulting in complex process and high cost

Method used

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  • Method for extracting high-purity ammonium thiocyanate and ammonium sulphate from coking desulfurization/decyanation waste liquor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] 1. Pretreatment of desulfurization and decyanation waste liquid

[0033] Take coke oven gas desulfurization and decyanation waste liquid 1100g [from Hebei Xuyang Coking Co., Ltd., wherein NH 4 SCN content 20.3wt%; (NH 4 ) 2 SO 4 Content 9.6wt%; (NH 4 ) 2 S 2 o 3 Content 0.6wt%], put it into the settling kettle and let it stand naturally for 10h. Filter to remove elemental sulfur and other solid impurities.

[0034] 2. Decomposition of ammonium thiosulfate

[0035] The desulfurization and decyanation waste liquid after preliminary filtration was placed in a decolorization kettle, and the air flow rate was 30ml / min. After stirring and heating at 85°C for 45 minutes, the measured pH value was 7.6.

[0036] 3. Decolorization and impurity removal

[0037] Then add 33g of activated carbon [purchased from Tianjin Guangfu Technology Development Co., Ltd.] into the decolorization kettle, decolorize at 60°C for 90min, and then filter.

[0038] 4. Concentrated crystalli...

Embodiment 2

[0043] 1. Pretreatment of desulfurization and decyanation waste liquid

[0044] The pretreatment of desulfurization and decyanation waste liquid was carried out in the same manner as in Example 1.

[0045] 2. Decomposition of ammonium thiosulfate

[0046] Except that the time of stirring and heating was 120 minutes instead of 45 minutes, the decomposition of ammonium thiosulfate was carried out in the same manner as in Example 1, and the measured pH value was 7.3.

[0047] 3. Decolorization and impurity removal

[0048] Decolorization and impurity removal were carried out in the same manner as in Example 1.

[0049] 4. Concentrated crystallization

[0050] Concentration crystallization was carried out in the same manner as in Example 1, wherein 105.5 g of ammonium sulfate product was obtained after crystallization at 48° C., wherein the ammonium sulfate content was 96.3 wt%, ammonium thiocyanate was 1.0 wt%, and the water content was 2.4 wt%. After crystallization at 15°C,...

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Abstract

The invention provides a method for recycling ammonium salt from chemical waste liquor generated in the desulfurization / decyanation process of coke oven gas, and particularly, the invention provides a method for extracting high-purity ammonium thiocyanate and ammonium sulphate from coking desulfurization / decyanation waste liquor. The purities of ammonium thiocyanate and ammonium sulphate produced by using the method disclosed by the invention are greatly improved in comparison with those of products produced by contrasted embodiments. According to the method disclosed by the invention, high-purity products can be prepared under the condition of only carrying out one-time step-by-step concentration, so that the wastewater discharge amount is reduced and the environment pollution of coking plants is alleviated; and high-purity and high-added-value chemical raw materials are recycled, thereby increasing the economic benefits of enterprises.

Description

technical field [0001] The invention relates to a method for recycling ammonium salts in chemical waste liquid produced in the desulfurization and decyanation process of coke oven gas. Specifically, the invention relates to a method for extracting high-purity ammonium sulfate and sulfur Ammonium cyanate method. Background technique [0002] At present, many domestic coking plants adopt PDS wet ammonia desulfurization and decyanation process. The process is independently developed and designed in my country, and has the advantages of high desulfurization and decyanation efficiency, small equipment investment, and easy operation. However, this method does not match the corresponding waste liquid treatment technology. The waste liquid produced by PDS wet ammonia desulfurization and decyanation process mainly contains ammonium thiocyanate, ammonium thiosulfate and ammonium sulfate. Among them, ammonium thiocyanate accounts for 18.5%-24.5%, ammonium sulfate accounts for 7.0%-1...

Claims

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Application Information

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IPC IPC(8): C01C3/20C01C1/24
Inventor 张英伟刘小晨张凌伟陈伟长孙长江
Owner BEIJING RISUN TECH CO LTD
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