Method for treating industrial mixed waste salt by using sulfuric acid

A sulfuric acid treatment and industrial technology, which is applied in the field of industrial mixed waste salt treatment, can solve the problems of difficult removal of organic and inorganic impurities, restrictions on the comprehensive utilization of waste acid, secondary pollution of the environment, etc., and meet the requirements of reducing the corrosion resistance of equipment , Solve the difficulty of waste acid treatment and realize the effect of comprehensive utilization

Pending Publication Date: 2022-01-07
ZHEJIANG LONGSHENG GROUP +2
View PDF5 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the existing waste sulfuric acid treatment processes, most of the treatment processes such as concentration, high-temperature pyrolysis, and neutralization have problems such as high energy consumption, incomplete treatment, and secondary pollution to the environment. The organic and inorganic impurities contained in the waste acid are difficult to Removal, limiting the comprehensive utilization of waste ac

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 treating industrial mixed waste salt by using sulfuric acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] Mix the industrial mixed waste salt with a sodium chloride content of 65.15% (mass fraction, the same below), a sodium sulfate content of 29.18%, a water content of 2.3%, and an organic impurity content of 3.37% in a mixing tank, and use high temperature After drying the residual heat of the treatment system, use the feeder to put the mixed waste salt into the rotary kiln incinerator. Under aerobic conditions, high-temperature incineration is carried out at 500-600°C to remove organic matter, and the waste salt stays in the incinerator for 1 hour, and the removal rate of organic impurities in industrial mixed waste salt is 98.9%.

[0038] Put the mixed waste salt after high-temperature incineration to remove organic matter into the reactor, and add waste sulfuric acid with a content of 65% (TOC=0.12%), and control the dosage of waste acid as sulfuric acid: sodium chloride and sodium sulfate Sum = 1.8:1 (molar ratio), react at 110°C for 1h. The tail gas produced by the ...

Embodiment 2

[0042] Mix industrial mixed waste salt with a sodium chloride content of 35.64%, a sodium sulfate content of 53.47%, a moisture content of 5.09%, and an organic impurity content of 5.8% in a mixing tank. The feeding machine puts the mixed waste salt into the rotary kiln incinerator. Under aerobic conditions, high-temperature incineration is carried out at 500-600°C to remove organic matter, and the residence time of waste salt in the incinerator is 1.5 hours. The removal rate of organic impurities in industrial mixed waste salt is 99.2%.

[0043] Put the mixed waste salt after high-temperature incineration to remove organic matter into the reactor. The acidic mother liquor in embodiment one is reused, mixed with 45% industrial waste acid (TOC=0.08%), then added to the reactor and mixed evenly with mixed waste salt, and the dosage of controlled waste acid is sulfuric acid in waste acid: The sum of sodium chloride and sodium sulfate = 1.5:1 (molar ratio), react at 80°C for 1 h...

Embodiment 3

[0047] Mix the miscellaneous salt obtained after the concentration and crystallization of the centrifuged mother liquor in Example 2 and the industrial miscellaneous waste salt in the mixing tank to obtain a sodium chloride content of 72.33% (mass fraction), a sodium sulfate content of 19.01%, and a moisture content of 5.61%. %, industrial mixed waste salt with an organic impurity content of 3.05%, after being dried by the waste heat of the high-temperature treatment system, the mixed waste salt is put into the rotary kiln incinerator using a feeder. Under aerobic conditions, high-temperature incineration is carried out at 500-600°C to remove organic matter, and the residence time is 1 hour. The removal rate of organic impurities in industrial mixed waste salt is 98.6%.

[0048] Put the mixed waste salt after high-temperature incineration to remove organic matter into the reactor. The industrial waste sulfuric acid (TOC=0.43%) containing 2.2% of hydrochloric acid and 25% of s...

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 treating industrial mixed waste salt by using sulfuric acid, the industrial mixed waste salt refers to industrial waste salt containing sodium chloride and sodium sulfate, and the method comprises the following steps: (1) adding a sulfuric acid aqueous solution with the concentration of more than 20% and the industrial mixed waste salt into a reactor, controlling the temperature to be 65-120 DEG C, reacting for 0.5-1.5 hours, and collecting volatile gas to obtain a byproduct hydrochloric acid; controlling the acidity of the obtained reaction liquid to be 55-85%, then cooling and crystallizing the reaction liquid, and separating to obtain sodium hydrogen sulfate crystals and acidic mother liquor; (2) mixing the sodium hydrogen sulfate crystal with industrial mixed waste salt, reacting at 450-600 DEG C for 3.0-6.0 hours to obtain crude sodium sulfate and hydrogen chloride-containing tail gas, and using the hydrogen chloride-containing tail gas for preparing byproduct hydrochloric acid; and (3) carrying out salt dissolving refining on the crude sodium sulfate, concentrating and crystallizing the refined solution, and separating to obtain the sodium sulfate product. The practical problem that industrial mixed waste salt is difficult to treat is solved, and the industrial anhydrous sodium sulfate and the byproduct hydrochloric acid which meet the quality requirements of national standard I-class first-grade products are prepared.

Description

(1) Technical field [0001] The invention belongs to the field of resource utilization of industrial waste salt, and in particular relates to a treatment method for industrial mixed waste salt containing sodium chloride and sodium sulfate. (2) Background technology [0002] Chemical production produces a large amount of waste salt such as waste sodium chloride and waste sodium sulfate, and high-concentration salt-containing organic wastewater or high-salt mother liquor through evaporation and crystallization also produces a large amount of waste salt containing organic matter. Salt separation, crystallization and recycling are currently waste The main idea of ​​salt disposal is that waste salt contains various impurities, making it impossible to enter the production system that requires high raw materials. Due to various factors, the harmless disposal and resource utilization of waste salt cannot be carried out on a large scale. At present, the final disposal method of waste ...

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): C01D5/02C01D5/16C01D5/18C01B7/03
CPCC01D5/02C01D5/16C01D5/18C01B7/035
Inventor 何旭斌何立阮金木陶建国吕赛君王江峰孟明
Owner ZHEJIANG LONGSHENG GROUP
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