It is generally accepted that the collector, potassium ethyl xanthate, will not float sphalerite. However, Gaudin showed that sphalerite readily floats if activated with certain metal cations before exposure to xanthate. Ralston and Hunter found that copper sulfate, is the best activator for sphalerite.
In recent years flotation reaction products formed on mineral surfaces have been analyzed by infrared techniques. Peck used the potassium bromide pellet technique to study oleic acid and sodium oleate adsorption on fluorite, barite, and calcite. Poling and Leja used the differential reflectance technique for studying the adsorption of xanthate on nickel surfaces. The Bureau of Mines used the internal reflection technique in conjunction with solvent extraction procedures to study the reaction of aqueous potassium ethyl xanthate on galena surfaces. In the internal reflection technique described by Harrick, a sample that selectively absorbs infrared radiation, when placed in contact with a reflecting prism, will produce an absorption spectrum that is characteristic of the material.
The objective of the research described in this paper was to determine the relationship between values of the pH of the collector solution and the amounts of the reaction products, cuprous ethyl xanthate and ethyl dixanthogen, adsorbed on sphalerite surfaces.