Cassiterite (SnO₂) is the principal tin ore mineral and its high density can favour gravity beneficiation. Because cassiterite is brittle, excessive grinding into fine slimes is an important preparation risk.
- Principal mineral
- Cassiterite (SnO₂)
- Important property
- High density and brittleness
- Preparation target
- Liberate while limiting fine losses
Why is cassiterite sensitive to overgrinding?
Cassiterite is a dense but brittle oxide mineral. Crushing and, where required, grinding support liberation, while excessive transfer to ultrafine fractions can make gravity separation more difficult.
Circuit design therefore monitors not only top size but also the quantity of fines and how cassiterite distributes into them.
The idea of early gravity recovery
Where coarse liberated cassiterite is present, gravity recovery at an appropriate size before fine grinding of the whole ore may reduce energy use and value loss.
The decision is based on testwork; the same staged flowsheet is not assumed for every tin ore.
What do screening and classification control?
Narrower size ranges can help gravity equipment operate more consistently. Screening and classification separate coarse recycle from fine product for different handling.
Aperture or cut size is chosen according to cassiterite liberation and the feed range of downstream equipment.
Required tests
- Cassiterite grain size and liberation degree
- Gangue and heavy-mineral associations
- Breakage and fines-generation tendency
- Feed/intermediate product PSD
- Gravity and other beneficiation testwork