Mechanism and technological results of sulfidation roasting of oxidized lead compounds

Abstract

The paper presents the results of a critical analysis of existing technologies for processing lead-zinc ores and industrial products; the relevance of the research lies in the development of methods aimed at additional extraction of zinc and lead in conditions of a rapid decrease in the content of lead and zinc in ores. The paper presents research on the thermodynamic justification of sulfiding roasting, the results of the development of technology for intensifying the process of processing poor, difficult-to-process complex lead-zinc ores and middlings through preliminary thermal activation by sulfiding roasting in a fluidized bed furnace. The mechanism of sulfidation of oxylated lead compounds has been established according to the scheme: PbO → PbO·PbSO4 → PbSO4 → PbS. The results of the physicochemical study of roasting products, as well as the results of magnetic enrichment of cinders, are presented. The results of magnetic separation of cinders after heat treatment of industrial products show that it is possible to separate up to 70% of iron in the form of pyrrhotite into a magnetic product, while the pyrrhotite content in the magnetic product is up to 98.2%. The paper presents a new technological scheme for processing lead-zinc industrial products from enrichment to obtain pyrrhotites with predicted properties.