Dissociation mechanism of particulate matter containing arsenic and lead in smelting flue gas by pyrite

Abstract

Copper smelters are the main anthropogenic source of arsenic. In this study, the formation pathway of arsenic-lead particulate matter in a heat recovery steam generator (HRSG) of a copper smelting facility were investigated. Lead monoxide and arsenic trioxide reacted easily with each other to form particulate matter with a high arsenic content, while the relative content of lead arsenate and lead arsenite in the particulate matter varied with the fluctuation of the smelting flue gas. The dissociation mechanism by pyrite of particulate matter containing arsenic and lead were also studied for the first time. The structures and components of the resultant composites were characterized by ion chromatography plasma optical emission spectrometry, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Pyrite promoted the dissociation of lead arsenate and lead arsenite due to the formation of more lead sulfate, and then further inhibited the formation of lead arsenate and lead arsenite. This study is of great significance for the control of arsenic in flues.