CASE ANALYSIS ON ENGINEERING APPLICATION OF USING INDIRECT THERMAL DESORPTION PROCESS TO REMEDIATE MERCURY-BEARING SOLID WASTE AND CONTAMINATED SOIL

A large-scale mercury contaminated site remediation project in Yunnan was the first project in China that used indirect thermal desorption process to remediate mercury-bearing solid waste and mercury-contaminated soil. We obtained relevant construction technology parameters through the engineering practice. When the thermal desorption temperature was 600~750 ℃ and residence time was 40~60 min, the total mercury in remediated material could reach the corresponding targets, which verified the remediation effect of indirect thermal desorption process. The implementation results of this project showed that indirect thermal desorption process had significant remediation effect on high level mercury-bearing solid waste and mercury-contaminated soil, the remediated material reached the corresponding targets, pollutants emission met the Integrated Emission Standard of Air Pollutants (GB 16297—1996) and it had no adverse impact on the environment. The process could also realize the resourcilization and recovery of mercury, and had wide application prospects and engineering reference value.