Pyrolysis treatment system for removing organics in chemical abraum salt

Abstract

The invention discloses a pyrolysis treatment system for removing organics in chemical abraum salt, and belongs to the field of treatment and disposal of the abraum salt and secondary pollution control. The pyrolysis treatment system comprises a first-level pyrolysis device, a second-level pyrolysis device and a waste gas treatment system, wherein the waste gas treatment system is composed of a quench tower, a spray tower and an organic waste gas purifying device. The chemical abraum salt is subjected to a first-segment low-temperature pyrolysis, moisture, hydrogen chloride and volatile organic pollutants are removed, then second-segment medium-temperature anaerobic pyrolysis is carried out at the temperature lower than salt melting temperature, so that the organics are subjected to pyrolysis to become a gaseous product, and the gaseous product is separated from the abraum salt; and meanwhile, the waste gas generated by the two segments of pyrolysis reaches the standard and is discharged after being treated by the waste gas treatment system. According to the pyrolysis treatment system for removing the organics in the chemical abraum salt, two segments of pyrolysis is used, the organics in the abraum salt can be removed, meanwhile, the pyrolysis temperature is controlled within a temperature interval generated by dioxin, and the purpose of controlling the generation of the dioxin is realized from the source. Therefore, the environmental risk of the abraum salt heat treatment is greatly reduced, and a beneficial route is provided for the recycling of dangerous wastes such aschemical industrial abraum salt.

Description

technical field [0001] The invention belongs to the field of treatment and disposal of waste salt in the chemical industry and secondary pollution control in the process, and in particular relates to a pyrolysis treatment system for removing organic matter in waste salt in the chemical industry. Background technique [0002] Dioxins are a type of highly toxic environmental pollutants, which are commonly found in waste gas from domestic waste incineration or hazardous waste incineration represented by medical waste and chemical waste. Waste salt is a typical solid waste common in the chemical industry. Waste salt in many industries contains a variety of toxic and harmful organic components, so it is included in the "National Hazardous Waste List". In recent years, the treatment and disposal of waste salt in the chemical industry has become one of the problems that need to be solved urgently in the industry. [0003] At present, pyrolysis purification and melting purification...

AI Technical Summary

Problems solved by technology

Although this technology can remove toxic and harmful organic substances in waste salt, there are still some shortcomings, such as uneven heating, low energy efficiency, and carbonization and coking of organic substances due to the influence of waste salt composition, shape, particle size and other factors. The quality of salt; waste salt melting and bonding is serious, easily corrodes the surface of equipment, and in severe cases will cause equipment damage; only consider the removal of toxic and harmful organic substances in waste salt, and the hazardous waste salt after treatment has a high content of impurities, which is still difficult to recycle , can only be landfilled, which not only causes a waste of resources, but also has a higher landfill cost

Due to the high temperature of waste salt melting, nitrogen oxides will be produced. At the same time, dioxins will also be produced if the process is not well controlled. Therefore, we must pay attention to the secondary pollution caused by high temperature melting of waste salt and its prevention and control.

[0004] In order to control the dioxin pollution produced by the waste salt pyrolysis or melting recovery process, the combination of process control and terminal control is generally adopted, such as the publication number CN107726851A "A method for converting chemical waste hazardous sodium chloride into refined industrial salt Furnaces and methods", Publication No. CN109990297A "Methods for Harmless Recycling of Hazardous Chemical Wastes Containing Salt" all use high temperatures above 800°C to carry out cascade combustion of waste salt. Although the generation of dioxins has been curbed from the source, the smoke There is still a potential risk of dioxin formation in the gas cooling process, and at the same time, the temperature is higher than the melting point of salt, which requires very high corrosion resistance for equipment

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