Mechanism research on arsenic removal from arsenopyrite ore during a sintering process

• Published in: International journal of minerals, metallurgy and materials Vol. 24; no. 4; pp. 353 - 359
• Main Authors: Cheng, Ri-jin, Ni, Hong-wei, Zhang, Hua, Zhang, Xiao-kun, Bai, Si-cheng
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.04.2017; Springer Nature B.V; Key Laboratory for Ferrous Metal urgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China
• Subjects: Aluminum oxide; arsenate; Arsenates; Arsenic; Arsenic removal; Arsenopyrite; Ceramics; Characterization and Evaluation of Materials; Chemical properties; Chemistry and Materials Science; Composites; Corrosion and Coatings; dearsenication; Glass; High temperature; Inductively coupled plasma; Iron ores; Low temperature; Materials Science; mechanisms; Metal oxides; Metallic Materials; Natural Materials; Oxygen; Pollutant removal; rate; removal; Residues; Sinter; Sintering; Spectrometry; Sulfur dioxide; Surfaces and Interfaces; Thin Films; Tribology; X-ray diffraction; X-ray spectroscopy; arsenopyrite; dearsenication rate; sintering; mechanisms; arsenic removal; arsenate
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-017-1414-5

The mechanism of arsenic removal during a sintering process was investigated through experiments with a sintering pot and arsenic-bearing iron ore containing arsenopyrite; the corresponding chemical properties of the sinter were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), and scanning electron microscopy (SEM) coupled with energy- dispersive X-ray spectroscopy (EDS). The experimental results revealed that the reaction of arsenic removal is mainly related to the oxygen atmosphere and temperature. During the sintering process, arsenic could be removed in the ignition layer, the sinter layer, and the combustion zone. A portion of FeAsS reacted with excess oxygen to generate FeAsO4, and the rest of the FeAsS reacted with oxygen to generate As2O3(g) and SO2(g). A portion of As2O3(g) mixed with Al2O3 or CaO, which resulted in the formation of arsenates such as AlAsO4 and Ca3(AsO4)2, leading to arsenic residues in sintering products. The FeAsS component in the blending ore was difficult to decompose in the preliminary heating zone, the dry zone, or the bottom layer because of the relatively low temperatures; however, As2O3(g) that originated from the high-temperature zone could react with metal oxides, resulting in the formation of arsenate residues.