ABSTRACT
Frother molecules have uneven distribution of polar and nonpolar groups which enables them to preferentially orient at water/air interface. There are three main groups of reagents employed by the mineral industry as frothers: alcohols, alkoxy-substituted paraffins and polyglycol-type frothers. In the flotation practice, frothability is commonly characterized by a foam volume. This value is measured under steady state conditions when a gas is injected with a constant velocity. According to S. A. Wrobel, firstly, froth selectivity decreases with an increase of the molecular weight and, especially, with the number of carbon atoms in the nonpolar group; secondly, it decreases with an increase of the molecular weight of the polar groups. The surface tension—adsorption isotherms can be used to evaluate the approximate average areas occupied by frother molecules at the air/bubble interface at each concentration. In conventional froth flotation, the additional upgrading in the froth depends on froth stability.
