Collaborative resource utilization of hazardous chromium ore processing residue (COPR) and C-bearing dust during limonitic laterite sintering process

• Published in: Journal of cleaner production Vol. 386; p. 135821
• Main Authors: Tu, Yikang, Zhang, Yuanbo, Su, Zijian, Jiang, Tao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2023
• Subjects: C-bearing dust; Clean utilization; COPR; Detoxification; Sintering; COPR; Clean utilization; C-bearing dust; Sintering; Detoxification
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2022.135821

Much chromite ore processing residue (COPR), which is defined as hazardous solid waste due to virulent Cr (Ⅵ), is produced from chromium salt industry. C-bearing dust from steel industry is a kind of typically solid waste with poor surface activity. The iron ore sintering process has the potential on large-scale harmless utilization of COPR and C-bearing dust. This study proposes a new approach of co-utilizing COPR and C-bearing dust during limonitic laterite sintering process. The negative influence of COPR and C-bearing dust on permeability was offset by the fuel attribute of extra C from C-bearing dust. The results indicate that, while 6% COPR and 8% C-bearing dust were added, the tumble index and yield of the sinters were basically equal to those of the blank samples. The toxic Cr (Ⅵ) was reduced to Cr (Ⅲ) which was concentrated in high alumina spinel phases during the sintering process. The obtained sinters were identified as nontoxic, and no secondary waste was generated throughout the clean utilization process. [Display omitted] •A collaborative process for co-utilizing COPR and C-bearing dust was proposed.•C-bearing dust could improve the negative effects of COPR during sintering process.•Toxic Cr (Ⅵ) from COPR was reduced to Cr (Ⅲ) and entered the high alumina spinel.•The composite limonitic laterite sinters were determined to be non-toxic.