Collectability and Selectivty of Frothers in Flotation
S. A. Kondrat’ev
Chinakal Institute of Mining, Siberia Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Flotation, surface active substances, collectability, selectivity, physisorption mechanism of collectors
Abstract
The mission of frothers consists in formation of fine bubbles and a frother layer of the required structure to influence floatability of minerals. The collecting and selective properties of frothers are reviewed. Based on the physisorption mechanism of reagents, a hypothesis of the collecting action of frothers in flotation is put forward. Surfactants, while reducing the time of inductance, remove the kinetic constrain of the mineral particle-gas bubble assembly formation. Collectability of surfactants is governed by their surface activity relative to the gas-liquid interface and by the density of adsorption at a mineral which is to be extracted. It is shown that frothers are effective at the gas-liquid interface rather than at the solid-liquid interface, and are not the selective collectors therefore. The high surface and flotation activities of frothers lead to the nonselective recovery of minerals in concentrates. It is proved that frothers with the low surface activity show weaker collecting properties on target minerals and on barren rocks, and, for this reason, are more selective reagents.
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