A comprehensive recovery process of desulfurization waste liquid auxiliary salt in coking plant

A technology for desulfurization waste liquid and auxiliary salt, which is applied in the direction of ammonium sulfate, thiosulfate/dithionite/polythionate, thiocyanate, etc., which can solve the problem of reducing the desulfurization effect and cannot fundamentally Solve problems, production equipment corrosion and other problems, achieve the effect of low energy consumption, avoid secondary pollution, and clear process

Inactive Publication Date: 2011-11-30
SHANDONG MEIKE POWER
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] For the treatment of this kind of desulfurization waste liquid, if the treatment method of returning to coal blending is adopted, the problem cannot be solved fundamentally
Since the coal with desulfurization waste liquid enters the coking furnace, it is still converted into sulfur compounds such as sulfur dioxide and hydr

Method used

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  • A comprehensive recovery process of desulfurization waste liquid auxiliary salt in coking plant
  • A comprehensive recovery process of desulfurization waste liquid auxiliary salt in coking plant

Examples

Experimental program
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Effect test

Embodiment 1

[0021] Take 1000g of desulfurization wastewater from coking enterprises (21.35% ammonium thiocyanate, 18.75% ammonium thiosulfate, 1.25% ammonium sulfate), decolorize at 5000Pa and 75°C for 5 hours at a vacuum degree, and put the decolorized liquid into the evaporating kettle at 5000Pa , 390 grams of water evaporated at 80°C. Cool down to 60°C, and use a centrifuge to separate out 148 grams of ammonium thiosulfate / ammonium sulfate compound salt; the separated liquid is filtered at 55°C, and the filtered liquid enters the crystallization kettle for crystallization, and the solution for washing the finished product of ammonium thiocyanate is added for 45 gram, the crystallization temperature is 25°C, the cooling rate is 3°C / h, kept at this temperature for 2h, centrifuged and washed to obtain 162g of finished ammonium thiocyanate, with a purity of 97.4% and a sulfur content of less than 0.05%. Add 148g of the separated ammonium thiosulfate / ammonium sulfate compound salt to 180g o...

Embodiment 2

[0023] Take 1000g of desulfurization wastewater from coking enterprises (ammonium thiocyanate 18.32%, ammonium thiosulfate 17.75%, ammonium sulfate 0.64%), first decolorize it at 5000Pa in vacuum at 75℃ for 5 hours, and put the decolorized liquid into the evaporating kettle at 5000Pa , 470 grams of water evaporated at 80°C. Cool down to 55°C, and use a centrifuge to separate 126 grams of ammonium thiosulfate / ammonium sulfate compound salt; the separated liquid is filtered at 50°C, and the filtered liquid enters the crystallization kettle for crystallization, and 35 g of the solution for washing the finished product of ammonium thiocyanate is added. grams, the crystallization temperature is 30°C, the cooling rate is 2°C / h, kept at this temperature for 1h, centrifuged and washed to obtain 146 grams of finished ammonium thiocyanate, with a purity of 96.8% and a sulfur content of less than 0.05%. Add 126g of the separated ammonium thiosulfate / ammonium sulfate compound salt to 134g...

Embodiment 3

[0025] Others are the same as in Example 2, except that the evaporated liquid after removing the ammonium thiosulfate does not adopt membrane filtration before entering the crystallization tank, and the cooling rate of ammonium thiocyanate crystallization is 6° C. / h. As a result, 132 grams of finished product ammonium thiocyanate was obtained, with a purity of 95.4%, and a sulfur content of 0.15%.

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Abstract

The invention belongs to the field of environmental protection, and particularly discloses a comprehensive recovery process for desulfurization waste liquid secondary salt in a coking plant. The comprehensive recovery process is characterized in that: the desulfurization waste liquid is decolorized, evaporated, and separated to obtain a solid mixture of ammonium thiosulfate and ammonium sulfate and a separation liquid, and the separation liquid is filtered, crystallized, washed, and dried to obtain ammonium thiocyanate finished product. The invention has a simple process and a clear process, and can simultaneously recycle three secondary salts of ammonium thiocyanate, ammonium thiosulfate and ammonium sulfate in the desulfurization waste liquid with less energy consumption. The whole process is a physical process, and no other chemicals are introduced to avoid It prevents secondary pollution and realizes the harmless treatment of wastewater.

Description

(1) Technical field [0001] The invention belongs to the field of environmental protection, and in particular relates to a process for comprehensively recovering secondary salt from desulfurization waste liquid in a coking plant. (2) Background technology [0002] my country's coke production capacity ranks first in the world. During the production process, nearly 1 / 3 of the sulfur is transferred from the raw coal to the coke oven gas produced. 2 S exists in the form of S, and HCN also exists in the coke oven gas, which requires them to be removed before the coke oven gas is used. [0003] At present, there are many desulfurization technologies in the coking industry, and the most widely used one is NH 3 HPF desulfurization process for alkali source. After using this process for desulfurization, the desulfurization waste liquid mainly contains NH 4 CNS, (NH 4 ) 2 S 2 o 3 and (NH 4 ) 2 SO 4 , these secondary salts are accumulated in the desulfurization liquid. Wh...

Claims

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Application Information

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IPC IPC(8): C01C3/20C01B17/64C01C1/24
Inventor 李晓梅
Owner SHANDONG MEIKE POWER
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