The Industrial Practice of POPs Contaminated Soil as Alternative Raw Materials in Clinker Production

This paper aims to study the co-processing of POPs (DDTs and HCHs) contaminated soil as an alternative raw material for sustainable clinker production. The milling system designed solely to contaminated soil was introduced with hot air (250-350 °C) to dry water and simultaneously vaporize POPs. The gaseous POPs was directly destroyed in the precalciner, while the milled soil with partly removal of organic pollutants was homogenized in a sealed silo and then took part in clinker sintering. According to the experiment results the moisture content reached an average of 0.4%, and the average 200 μm and 80 μm sieve residues were 1.9% and 19.0% respectively after grinding. Furthermore, clinkers and emission which were produced with contaminated soil as SiO2 substitute were monitored. There was no DDTs and HCHs residue both in clinkers and in exhaust, which demonstrated the success of eliminating organic pollutants and utilizing the soil as alternative SiO2 materials in our cement plant.