The influence of heavy metals on the polymorphs of dicalcium silicate in the belite-rich clinkers produced from electroplating sludge.
The purpose of this study is to utilize an electroplating sludge for belite-rich clinker production and to observe the influence of heavy metals on the polymorphs of dicalcium silicate (C(2)S). Belite-rich clinkers prepared with 0.5-2% of NiO, ZnO, CuO, and Cr(2)O(3) were used to investigate the individual effects of the heavy metals in question. The Reference Intensity Ratio (RIR) method was employed to determine the weight fractions of gamma-C(2)S and beta-C(2)S in the clinkers, and their microstructures were examined by the transmission electron microscopy (TEM). The results showed that nickel, zinc, and chromium have positive effects on beta-C(2)S stabilization (Cr(3+)>Ni(2+)>Zn(2+)), whereas copper has a negative effect. The addition of up to 10% electroplating sludge did not have any negative influence on the formation of C(2)S. It was observed that gamma-C(2)S decreased while beta-C(2)S increased with a rise in the addition of the electroplating sludge. Moreover, nickel and chromium mainly contributed to stabilizing beta-C(2)S in the belite-rich clinkers produced from the electroplating sludge.
Chen
Ying-Liang
YL
Department of Environmental Engineering, National Cheng Kung University, Tainan City 70101, Taiwan, ROC.
Shih
Pai-Haung
PH
Chiang
Li-Choung
LC
Chang
Yi-Kuo
YK
Lu
Hsing-Cheng
HC
Chang
Juu-En
JE
D017610:Calcium Compounds / Q000737:chemistry*; D002857:Chromium; D003247:Conservation of Natural Resources / Q000379:methods; D004595:Electroplating; D005899:Glass Ionomer Cements / Q000138:chemical synthesis*; D019216:Metals, Heavy / Q000737:chemistry*; D009532:Nickel; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage; D017640:Silicates / Q000737:chemistry*; D017641:Zeolites / Q000138:chemical synthesis*; D015032:Zinc
D017610:Calcium Compounds; D005899:Glass Ionomer Cements; D019216:Metals, Heavy; D012722:Sewage; D017640:Silicates; C516482:belite; D002857:Chromium; C013481:dicalcium silicate; D017641:Zeolites; D009532:Nickel; D015032:Zinc