Beneficiation of Ultrafine Cassiterite from a Tin Tailings by Flotation

With the continuous depletion of primary tin ores, tin tailings has become an important source for the production of tin; however, the large-scale utilization of tin tailings is disappointedly scarce, due to its leanness in valuable minerals and insufficient methods available for processing such low-grade tailings. A flotation process has been used on a laboratory scale to investigate the effects of various reagents such as salicylhydroxamic acid, lead nitrate, sodium hexametaphosphate and pine oil on tin recovery at neutral pulp. Because cassiterite is friable and a large amount of fines and slimes were generated, usually de-sliming is used to prevent slime coating and to increase the recovery of tin. However, analyses have shown that fine particles in the sample mostly contain tin, thus de-sliming was not suggested. By applying the process, ultrafine cassiterite could be efficiently recovered from the slime tailings, and the concentrate assaying 1.82% Sn with a recovery of 76.90% was obtained.