Study On Mechanisms And Application Of Combined Collectors In Fine Cassiterite Flotation

Recovering fine-grained cassiterite effectively is a hard problem. Flotation is an important method, and the collector is the key to ensure the separation efficiency.This paper mainly focused on the flotation mechanism of combined collectors, and the laboratory researches on usage of combined collectors were also carried out systematically.In this paper, researches on flotation of cassiterite, calcite, quartz pure mineral and the artificial mixture were carried out, using ZF, auxiliary reagent (TBP) and other conventional flotation reagents as collectors.Results showed that the optimal pH values of each collector were different;each collector at the optimal pH values range of cassiterite flotation were different; calcite had good floatability at the pH range,but quartz basically didnot float (or had a low recovery rate); depressants used in the experiment showed inhibition on the three kinds of pure minerals.The process mineralogy research results showed that the content of Sn was 0.79%, and cassiterite in the sample was like pitting sparse or densely distributed, and the cassiterite was fine-grained, the ore are hard to process. The following process flowsheeet was adopted:firstly sulfide-removing by flotation was used to eliminate the effect of sulfide minerals in the subsequent separation, then the magnetic separation of magnetite was conducted. The tailings are classified into two size fractions, the coarse fraction is gravity separated to recover as much cassiterite as possible. Fine fraction is deslimed to ensure the total tin recovery, while for the flotation process of rough concentrate, gravity separation is used first followed by reconcentration. Thereby the total tin concentrate contained 40.48% tin with recovery 53.77%.Zeta-potential measurement results showed that the surface Zeta potential of cassiterite shifted negatively when adding in combined collectors. The relation between Zeta-potential and pH environment was more obvious,but the relationship with the collector dosage is not significant.Infra-red spectrum tests showed that the characteristic absorption peak of cassiterite was shifted, and new characteristic peaks on the surface of cassiterite were generated. The functional group C=O and P=O in the combined collector formed a multi-chelate with Sn ion, after reacting with reagents, a plenty of non-polar hydrocarbon groups were formed on the surface of cassiterite, in terms of their hydrophobic effect, the cassiterite could float to the froth.