A Study on the Reaction Rate of Iron Sulfide Production from Iron Oxide Sulfidation

This chapter delves into the sulfidation process of iron oxides, a crucial step in metal extraction, particularly for iron. The study focuses on the reaction rates and parameters that influence the efficient conversion of iron oxides into iron sulfides using a rotary kiln. Key topics include the effects of temperature, partial pressures of the sulfidizing agent, and the composition of the iron oxide precursor on the sulfidation process. The research also addresses the challenge of interpreting results due to the existence of several liquid phases during the reaction, which complicates the application of existing models. The study found that the reaction rate for hematite sulfidation increased from 0.0074 cm s−1 to 0.018 cm s−1 and for magnetite sulfidation from 0.038 cm s−1 to 0.148 cm s−1 at temperatures between 650 °C–750 °C. The activation energy of the intrinsic chemical reaction and product layer diffusion for iron oxide sulfidation were calculated, and the residence times were simulated for a pilot-scale demonstration in a rotary kiln. The average calculated reaction order for the experiments was 1.05. This detailed investigation provides valuable insights into optimizing the sulfidation process for enhanced metal recovery from low-grade ores or recycled streams.