XU Yahong, XU Zhonghui, JIANG Zao, et al. Immobilization of COPR from lime-free roasting process by self-propagating high-temperature synthesis of Al-Fe2O3 and Mg-Fe2O3 systems[J]. CIESC Journal, 2017, (11): 4309-4315. DOI: 10.11949/j.issn.0438-1157.20170497.
XU Yahong, XU Zhonghui, JIANG Zao, et al. Immobilization of COPR from lime-free roasting process by self-propagating high-temperature synthesis of Al-Fe2O3 and Mg-Fe2O3 systems[J]. CIESC Journal, 2017, (11): 4309-4315. DOI: 10.11949/j.issn.0438-1157.20170497.DOI:
Two self-propagation high-temperature synthesis systems (SHS)
Al-Fe2O3 (thermite) and Mg-Fe2O3 (magnesium thermite)
were utilized to immobilize the chromite ore processing residue (COPR) from lime-free roasting process. The solid waste-extraction procedure was adopted to evaluate the treatment efficiency of COPR. The results showed that the SHS was an effective remediation technology for COPR with maximum solidify rate of 80% and 85%
respectively. The leaching toxic concentrations of total Cr and Cr(Ⅵ) in solidified products were less than 4.5 and 1.5 mg·L-1 respectively
and the final products could be disposed in the landfill site according to GB 16889-2008. During the SHS process
the reduction rate of Cr(Ⅵ) was higher than 90% and the reducing substance was dispersed in the solidified products in the form of amorphous state. Meanwhile
parts of the chromium ions were participated in the formation of minerals such as MgAlCrO4 spinel. Eventually
the chromium element was incorporated into the wasteforms in the form of chemical immobilization and physical encapsulation.