Hydrophobic character of nonsulfide mineral surfaces as influenced by double-bond reactions of adsorbed unsaturated collector species. Progress report, 15 December 1990--14 December 1991

摘要

A unique in-situ sampling technique has been developed which allowed for real-time analysis of surfactant adsorption processes on mineral single crystals. This technique couples FT-IR spectroscopy and internal reflection spectroscopy (FT-IR/IRS) and the mineral single crystal is referred to as a ''reactive'' internal reflect element (IRE). The single crystal is reactive in the sense that the adsorption occurs directly upon the surface of the IRE, which also serves to transmit IR electromagnetic radiation. The in-situ FT-IR/IRS method was previously demonstrated for the fluorite (CaF(sub 2))/oleate flotation system. Information obtained from this system included adsorption density (from mid- and near-infrared spectra), adsorption state and reactivity of adsorbed collector, and alkyl chain conformational analysis. In the second budget period, similar analyses have been performed for three other mineral systems. These systems are as follows: Insoluble Oxides: sapphire ((alpha)-Al(sub 2)O(sub 3))/sodium dodecylsulfate; Soluble Salts: sylvite (KCl)/n-octylamine; and Semisoluble Salts: calcite (CaCO(sub 3))/sodium oleate and fluorite (CaF(sub 2))/sodium oleate.