A pyrolysis treatment system for removing organic matter in chemical waste salt

Abstract

The invention discloses a pyrolysis treatment system for removing organic matter in chemical waste salt, belonging to the field of waste salt treatment and secondary pollution control, including a primary pyrolysis device, a secondary pyrolysis device and a quenching tower , a spray tower and an exhaust gas treatment system composed of a purification device for organic waste gas. The chemical waste salt undergoes a low-temperature pyrolysis to remove moisture, hydrogen chloride and volatile organic pollutants, and then performs a second-stage medium-temperature anaerobic pyrolysis at a temperature lower than the salt melting temperature, so that the organic matter in it is pyrolyzed into gaseous products. At the same time, the waste gas generated by the two-stage pyrolysis is treated by the waste gas treatment system and discharged up to the standard. The present invention utilizes two-stage pyrolysis, which not only can remove the organic matter in the waste salt, but also controls the pyrolysis temperature outside the temperature range where dioxins are easily generated, thereby realizing the purpose of controlling the generation of dioxins from the source. Therefore, the present invention greatly reduces the environmental risk of heat treatment of waste salt, and provides a beneficial path for the recycling of hazardous waste such as waste salt in the chemical industry.

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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