Migration and distributions of arsenic and antimony during co-processing hazardous waste in cement kilns

Abstract

Arsenic (As) and antimony (Sb) are heavy metals that have a toxic effect on human and environmental biology. Industrial tests were conducted on cement kiln co-processing of industrial sludge containing arsenic and waste resin containing antimony. The migration and distributions of arsenic and antimony in the cement kiln were studied. For antimony, the time required to establish a new mass balance and reach the steady state was significantly shorter than that for arsenic. Under the assumption that the input rates of arsenic and antimony in the co-processing test were 100%, almost all of the antimony and 70·52% of the arsenic were removed from the kiln as clinker. Minimal amounts of arsenic and antimony were emitted to the atmosphere via flue gas. 0·96% of arsenic and 4·37% of antimony formed external circulation with the cement kiln dust. 105·43% of arsenic and 123·56% of antimony were introduced by waste incineration residues and led to internal circulation with the hot meal in the kiln. Some arsenic (28·51%) accumulated in the kiln and was not discharged. The antimony inputs and outputs agreed with the mass balance. The mass distribution ratios in the clinker, flue gas and kiln dust varied with changing inputs of arsenic and antimony.