It really depends on the particle size of the cassiterite. Using both gravity and flotation will maximise both - flotation for fine grained cassiterite, and gravity recovery for the coarse. Have you conducted SxS Sn analyses?

I concur with your suggestions. There are three pieces of information one should have: 1) liberation size and top grain size of the cassiterite, 2) size by size analysis (SxS), and 3) green field or brown field context. Cassiterite is brittle and the design of the comminution circuit may limit what can be achieved by gravity separation which works best at the coarser sizes. Cassiterite is an oxide mineral and the gangue minerals as well as the quality of the process water will impact the ease of recovery by flotation because the reagent chemistry is not as straightforward as for a sulphide flotation.

Gravity separation is most suitable option for cassiterite ore up gradation. As a process engineer developed gravity separation performed for tin ore process and process simulation excel model is developed by me for process and operation cost optimization.

I do agree with him as well. Please let me know If you are interested in visiting a flotation + gravity separators mill.

Have done both, but gravity needs a much larger plant area so prefer flotation when practical as per his comment.

First let us get some data on liberation size; then carry out some laboratory tests on both gravity and flotation. Depending on grades and recoveries we may use either (first preference to gravity, if both give same outputs) and a combination.

The SGS Min Pro Lab in the UK has an extensive knowledge in this subject, I would suggest contacting them.

Part 1 : All mineral separations, flowsheet developments and equipment selection are based on a good understanding of the mineralogy of the ore types you propose to treat. Gravity is a good selection and can be employed down to very fine size fractions with modern developments in spiral technologies. Flotation can be useful, however depends upon the gangue minerals. For example, if sulphide minerals are reasonably abundant, if not dominant (cf. the Renison operation in Tasmania - cassiterite in pyrrhotite) so-called reverse flotation i.e. flotation of the sulphide minerals would be used. Otherwise, like floating scheelite and other oxide minerals, physical flotation with rather exotic collectors is required.

Part 2: While typically less selective than sulphide flotation techniques and requiring more cleaning stages, the Chinese have greatly improved the performance of these collectors, although gravity and leaching are often used to upgrade the concentrate- although driven by the gangue minerals and associations. My final comment concerns comminution and the selection of equipment. Like all brittle minerals, size reduction needs to be controlled with separation occurring at the coarsest mineral size. Thus grinding classically employs rod mills while I recommend that pre-concentration at coarser size fractions be investigated - note that full liberation is not required either for pre-concentration or even the rougher separation stages - careful regrinding of the concentrates would be practised (cf. porphyry copper and graphite flowsheets) - treating lower volumes lowers capex and opex and improves the NPV as well as lower the cut-off grade (more reserves).