Hydrophobic character of nonsulfide mineral surfaces as influenced by double-bond reactions of adsorbed unsaturated collector species. Progress report, 15 December 1992--14 December 1995

摘要

Goal is to provide a basis for improved flotation separation efficiency in nonsulfide minerals by establishing the collector (surfactant) adsorption reactions and developing appropriate surface chemistry control strategies. In-situ measurements of surfactant adsorption were made for selected nonsulfide mineral systems using FT-IR/IRS with reactive internal reflection elements. The IRS adsorption density equation was developed to measure the surfactant adsorption, and its validity was confirmed using transferred Langmuir-Blodgett films. Order and organization of adsorbed surfactants were established from linear dichroism spectroscopy. Hydrophobicity and stability of adsorbed surfactants at mineral surfaces can now be explained. The surface charge/collector colloid adsorption mechanism was used to explain the anomalous behavior of KCl and flotation of double salts (schoenite, kainite, borax, etc.) from saturated brines. Adsorbing surfactnat colloids at salt surfaces in brines were studied by photon correlation spectroscopy and atomic force microscopy. Studies are being initiated of the interparticle forces in soluble salt flotation and of interfacial water near hydrophilic and hydrophobic surfaces.