Surface activity and mercury flotation in solutions of n-dodecanoic acid and n-dodecylamine

Abstract

Abstract:The flotation and adsorption properties of two ionic collectors (n-dodecylamine and n-dodecanoic acid) are compared on the bases of results of mercury flotation in the model flotation apparatus and electrochemical measurements of the double layer capacity.The flotation recovery and the adsorption parameters (standard free enthalpy AG~, the interaction coefficient of Frumkin's isotherm, the surface area per molecule) have been determined withi n the pH range 2.5 -12 in solutions of various collector concentrations containing 0.1 N KCI. The maxima of flotation recovery and surface excess have been found at pHs corresponding to pK values for both substances. The influence of the electrolyte on flotation recovery and the gas bubble size distribution dependent upon the pH of the solution is presented for n-dodecanoic acid. The maxima of flotation recovery are involved through the formation of ion-molecule associates (1:1) as well as an optimum of the bubble size distribution.