Study of the heavy metals residual in the incineration slag of textile dyeing sludge

The effects of various incineration conditions on the residual ratios of Cu, Cr, Cd, Pb, Ni and Zn in the slag of textile dyeing sludge were investigated. The results indicated that higher temperatures (1000 - 1100 degrees C) were conducive to the solidification of Cu, Ni and Zn in the slag and that a lower temperature (700 degrees C) was conducive to the solidification of Cr, Cd and Pb. The residual ratios of Cu, Cr, Cd and Ni exhibited similar tendencies as the residence time increased, but Pb exhibited a negative correlation. The residual ratios of Cu, Cr, Ni and Zn were relatively stable as the moisture increased except for those of Cd and Pb. The residual ratios of Cr, Zn, Pb and Cd increased as the CaO dosage increased, but Cu exhibited a negative correlation. For XRD analysis, a higher temperature and the CaO additive had a positive effect on the crystallization of heavy metals during incineration. (C) 2014 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.