The Significance of Flotation Frothers Chemical Structure and Fundamental Properties: A Review

Froth flotation is a separation process widely used in the mineral processing industry that depends on differences in particle surface properties to separate valuable materials from undesired gangue. In froth flotation, an addition of a surfactant, acting as frother is usually needed. The basic function of the frother is to produce a swarm of air bubbles, which remain sufficiently stable for the hydrophobic mineral particles to be captured by them. This Paper presents a combination method of a foaming agent-surfactant composition with desirable selectivity and foaming properties. Wherein 1-butanol (C4H10O) is a main flotation foaming agent, which decides bubble sizes in a collecting area;and tetraethylene glycol (C8H18O5) is an auxiliary foaming agent, which affects a rising velocity of the bubbles in the collecting area and a foaming capability in a selected area. Set concentrations of the two components are respectively 60 ppm for the 1-butanol and 120 ppm for the tetraethylene glycol. An addition sequence is the 1-butanol followed by the tetraethylene glycol. The dual advantages of the selectivity and foaming properties of the foaming agent-surfactant composition in the present disclosure are verified through a series of tests, and desirable yields can be obtained in practice.

Effect of some operational variables on bubble size in a pilot-scale mechanical flotation machine

This work aims to provide a relationship of how the key operational variables of frother type and impeller speed affect the size of bubble （D32）. The study was performed using pilot-scale equipment （0.8 m^3） that is up to two orders of magnitude larger than equipment used for studies performed to date by others, and incorporated the key process variables of frother type and impeller speed. The results show that each frother family exhibits a unique CCC95-HLB relationship dependent on n （number of C-atoms in alkyl group） and m （number of propylene oxide group）. Empirical models were developed to predict CCC95 from HLB associated with other two parameters a and ft. The impeller speed-bubble size tests show that D32 is unaffected by increased impeller tip speed across the range of 4.6 to 9.2 m/s （representing the industrial operating range）, although D32 starts to increase below 4.6 m/s. The finding is valid for both coalescing and non-coalescing conditions. The results suggest that the bubble size and bubble size distribution （BSD） being created do not change with increasing impeller speed in the quiescent zone of the flotation.