Production Practice of Fine Cassiterite Flotation

摘要

The results of the plant-scale flotation of sulphide-type cassiterite slime are presented. Tolyl arsonic acid is used as cassiterite collector and sodium carbonyl methyl cellulose as calcite depressant. Rougher flotation after intensive agitation with these reagents for 50 min can greatly improve cassiterite flotation performance. When the slime contains 0.6-0.7% Sn a concentrate grading 25-30% Sn is obtained in commercial scale operation at 65% overall recovery (cassiterite flotation recovery 90%). The figure is more than twice the shaking-table recovery. The response of fine cassiterite to flotation process is very marked. Recoveries of Sn in concentrate of various size fractions are: +74 micrometers 72.02%, - 74 micrometers to +19 micrometers 95.95%, -19 to + 10 micrometers 95.28%, -10 micrometers 66.86%. Good recoveries in the size range from -74 to + 10 micrometers are obtainable when the reagents and flotation flowsheet are used. The Chang-Po cassiterite flotation plant (100 t/day capacity) was built in the Da-Chan area, Guangxi Province, China, in 1975. Tin slime containing 0.6-0.7% Sn from the gravity concentration plant is treated. In the period 1977-82 a flotation concentrate grading 26.79-30.83% Sn was produced. The overall recovery of Sn, comparing with an all-gravity process, has been increased by 4-6% since cassiterite flotation was introduced.