Cassiterite practices

Understanding the interaction of tin collectors with chemical parameters associated with pulp chemistry and adsorbtion of cassiterite is quite difficult to reconcile with actual plant practice. 

A phenomenon observed in both laboratory and pilot plant testing of ores with phosphonic acid collectors is complete cassiterite flotation at a pH below 4.0. In fundamental practice, it indicates that a pH region below 4 is the region of maximum flotation. However, in plant practice, at a low pH (below 4), loss of flotation occurred. The loss of flotation at a low pH has not been established. It is, however, postulated that loss of flotation is believed to be associated with complex solution chemical interaction between phosphonic acid collectors and cationic species, in particular, those of iron, which is always present in industrial flotation pulp. 

Ore that contains pyrophyllite similarly pyrophyllite can be selectively floated ahead of cassiterite using a combination of tall oil and alkyl sulphate. This method is practiced in the Galimovsky plant in Russia. 

Fusion decomposition provides an alternative digestion method. This is a high-temperature technique where powdered samples are heated with a suitable flux to produce a residue that may be readily dissolved. Fusion decompositions are the most rigorous digestions available and all silicate materials can be brought into a complete solution when fused with an appropriate flux. The principal disadvantage of the fusion technique is the introduction of extra salts into the final solution from the flux (thereby increasing total dissolved solids). Fusion decomposition remains the preferred technique for quantitative analysis of silicon, and may be the only practical method for complete decomposition of refractory minerals such as zircon, rutile, and cassiterite. Many fluxes have been used, but perhaps the most commonly used is lithium metaborate (LiBOs). This flux introduces only Li and B into the final solution, and is used at a relatively low flux sample ratio of 3 1. 

Gaft M, PanczCT G (2013) Lasta- induced time resolved luminescence spectroscopy of minerals - a powerful tool for stedying the nature of emission centers. Miner Petrol 107 363-372 Gaft M, Vorontsova L (1982) Luminescence of cassiterite and the possibilities of its practical use. Miner J4(5) 75-78... 

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