Disposal of historically contaminated soil in the cement industry and the evaluation of environmental performance

摘要: Abstract Approximately 400 000 t of DDTs/HCHs-contaminated soil (CS) needed to be co-processed in a cement kiln with time limitation 2 y. A new pre-processing facility “drying, grinding and DDTs/HCHs vaporizing” ability was equipped meet the technical requirements for processing raw meal environmental standards stack emissions. And bottom precalciner high temperatures >1000 °C chosen as CS feeding point co-processing, which has rarely been reported. To assess performance pre- co-processing technologies, according local regulation, test burn performed by independent accredited institutes systematically determination clinker quality, gas emissions destruction efficiency pollutant. The results demonstrated that quality not adversely affected co-processing. Stack were all below limits set Chinese standards. Particularly, PCDD/PCDF ranged from 0.0023 0.0085 ng I-TEQ Nm −3 . less toxic OCDD peak congener procedure, while most congeners (i.e. 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD 2,3,4,7,8-PeCDD) remained minor proportion. Destruction removal (DRE) (DE) system better than 99.9999% 99.99%, respectively, at highest rate during normal production. guarantee quarterly emission also monitored whole period. can national requirements.