2016 Volume 56 Issue 6 Pages 953-959
A novel method of reduction roasting of tin-bearing iron concentrates using pyrite (FeS2) is proposed, in which hematite in tin-bearing iron concentrates is reduced to magnetite (Fe3O4) and cassiterite (SnO2) is transformed to volatile tin sulphide (SnS). In a certain range, tin removal and iron reduction rates both increase with roasting temperature, pyrite amounts and residence time. When pyrite amounts exceed 5.00 mass%, some of the produced magnetite will be sulfurated to FeS and the evaporation of SnS (g) will also be obstructed. Tin content of the concentrate is decreased to 0.07 mass% and hematite is reduced to magnetite completely under the conditions of N2 flow rate of 5.00×10−6 m3/s, roasting temperature of 1473.0 K, residence time of 60 min, pyrite addition amounts of 5.00 mass% and concentrates particle size of 0.075 mm. The roasting products can meet the standard of BF ironmaking, which requires tin content in iron ores less than 0.08 mass%, and the tin removed can be recycled through smoke dust collection.
