Reduction behavior of tin-bearing iron concentrate pellets using diverse coals as reducers

Using optical microscopy, XRD, SEM, and EDS, the effects of diverse coals on the reduction behavior of tin-bearing iron concentrate pellets were studied in this research. The results indicated that anthracite and coke breeze could be used as suitable reducers to separate tin from the tin-bearing iron concentrate pellets. Lignite and semi-coke with good reactivity accelerated the generation of metallic iron and metallic tin and caused Fe–Sn alloy to easily form in the reduced pellets; this had an adverse effect on tin volatilization from the roasted pellets. When using anthracite and coke breeze as reducers, the majority of the tin was effectively volatilized as SnO(g) at higher temperature. The finished pellets contained a large amount of recrystallized wustite, some unreduced magnetite, and a small amount of metallic iron. Some fayalite also formed in all of the reduced pellets but was incompletely crystallized.

► Effect of coal reactivity on reduction of tin-bearing iron ore pellets is studied.
► Coal reactivity has obvious impact on tin deprivation from the pellets.
► Tin is effectively volatilized if using anthracite or coke breeze as reducer.
► Microstructure features of pellets reduced by diverse coals are investigated.