Investigation on the mechanism of ring formation in the process of NaCl recovery by pyrolysis of chemical waste salt using rotary kiln

Abstract

Chemical waste salt is a hazardous waste generated during chemical production, and it is crucial to complete the recycling of the waste salt in a practical way. In the case of waste salt recycling by rotary kiln pyrolysis carbonization, ringing affects the pyrolysis efficiency and process running, thus a study on waste salt ringing was conducted. The results showed that the particle size is the key to the ring formation in rotary kiln, and pyrolysis temperature, pyrolysis time and temperature distribution in the rotary kiln also affect the material discharge rate during pyrolysis of waste salt in the rotary kiln. Thermogravimetric analysis and SEM images revealed that the volatilization of organic matter in the material due to pyrolysis caused a decrease in the abrasion resistance of the waste salt particle, which was the factor behind the ringing during pyrolysis in the rotary kiln. This study may provide a reference for the implementation of similar waste salt pyrolysis carbonization processes.