Method for improving purity of sodium thiocyanate in coking and desulfurizing waste liquid

A technology of coking desulfurization waste liquid and sodium thiocyanate, which is applied in the direction of thiocyanate, etc., can solve the problems of restricting usage and price, affecting the purity of sodium thiocyanate, mixed crystals, etc., and achieves convenient operation, reduction of emissions and environmental protection Contamination, simple effect of extraction method

Inactive Publication Date: 2014-03-26
北京艾思合众环保科技有限公司
View PDF2 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Affected by the solubility of the three salts, mixed crystals will appear during the fractional crystallization process, resulting in a small amount of sodium sulfate and sodium thiosulfate mixed in the obtained sodium thiocyanate sal

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for improving purity of sodium thiocyanate in coking and desulfurizing waste liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] A method for improving the purity of sodium thiocyanate in coking desulfurization waste liquid, comprising the steps in sequence:

[0019] Pretreatment of desulfurization and decyanation waste liquid: take coke oven gas desulfurization and decyanation waste liquid 1000g, wherein sodium thiocyanate content is 10wt%, sodium sulfate content is 3.5wt%, sodium thiosulfate is 7.5wt%, filter to remove simple substance Sulfur and solid impurities;

[0020] Decolorization and impurity removal: place the desulfurization and decyanation waste liquid initially filtered in step (1) in a decolorization kettle, add 50 g of activated carbon, decolorize at 60° C. for 90 minutes, and then filter to obtain a clear liquid;

[0021] Initial concentration and crystallization: transfer the clear liquid filtered in step (2) to the concentration kettle for concentration under reduced pressure, the vacuum degree is 0.075Mpa, the concentration temperature is 75°C, after concentration, 750g of deh...

Embodiment 2

[0026] A method for improving the purity of sodium thiocyanate in coking desulfurization waste liquid, comprising the steps in sequence:

[0027] Pretreatment of desulfurization and decyanation waste liquid: take coke oven gas desulfurization and decyanation waste liquid 1000g, wherein sodium thiocyanate content is 10wt%, sodium sulfate content is 3.5wt%, sodium thiosulfate is 7.5wt%, filter to remove simple substance Sulfur and solid impurities;

[0028] Decolorization and impurity removal: place the desulfurization and decyanation waste liquid initially filtered in step (1) in a decolorization kettle, add 50 g of activated carbon, decolorize at 60° C. for 90 minutes, and then filter to obtain a clear liquid;

[0029] Initial concentration and crystallization: Transfer the clear liquid filtered in step (2) to a concentration kettle for concentration under reduced pressure, the vacuum degree is 0.075Mpa, the concentration temperature is 75°C, and the concentrated slurry is sen...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a method for improving the purity of sodium thiocyanate in a coking and desulfurizing waste liquid, which comprises the following sequential steps: (1) pretreating; (2) decoloring and removing impurities; (3) performing primary concentrating crystallization; (4) performing extraction separation; (5) performing secondary concentrating crystallization; and (6) washing, and drying, wherein the sodium thiocyanate product obtained after drying has a purity of 98% or above. According to the invention, the extraction method is simple and convenient to operate, and the salt content in a desulfurizing and decyanation waste liquid generated in a PDS desulfurizing production process of a coke-oven plant is effectively extracted and separated, so that the high-purity sodium thiocyanate product is extracted through concentrating crystallization; and the discharge of waste water from the coke-oven plant and environmental pollution are reduced, the high-purity high-added-value chemical raw material is recovered at the same time, and economic benefits of the enterprise are increased.

Description

technical field [0001] The invention relates to the technical field of using coke oven gas desulfurization waste liquid, in particular to a method for improving the purity of sodium thiocyanate in coking desulfurization waste liquid. Background technique [0002] At present, some domestic coking plants adopt PDS wet desulfurization and decyanation process. The process has the advantages of high desulfurization and decyanation efficiency, small investment in equipment, and simple operation. However, this method does not match the corresponding waste liquid treatment technology. The waste liquid produced by the PDS wet sodium desulfurization and decyanation process mainly contains sodium thiocyanate, sodium thiosulfate and sodium sulfate, of which sodium thiocyanate accounts for 8.5% to 20.5%, and sodium sulfate accounts for 3% to 8%. , sodium thiosulfate accounted for 7% to 14.5%. [0003] At present, waste liquid treatment mainly adopts the method of vacuum concentration ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C01C3/20
Inventor 陈海勇景建克张扬童国平雷晓东章成海陈淦勇杜伟赵孝忠
Owner 北京艾思合众环保科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap