Froth Flotation

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• physico-chemical method of concentrating

• involves use of chemicals to create favorable conditions for attachment of mineral particles to air bubbles

• air bubbles carry the mineral particles to a stable froth

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Scientific Basis

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• affinity of hydrophobic solid surfaces for gas bubbles

• hydrophobicity

• gas bubble surfaces are naturally hydrophobic

• gas bubbles also lighter than water by orders of magnitude

• bubble-solid aggregate is also lighter than water - buoyancy

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Process

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• few solids are naturally hydrophobic

• most solids need chemical treatment to make them hydrophobic

• a froth or foam is required to trap bubble-particle aggregates

• hydrophillic solids are wetted by water and therefore do not attach to air bubbles