ABSTRACT
The fundamental studies on the electrochemical behavior of almandite in an aqueous solution were made by electrophoretic and adsorptron measurements. From these measurements, it is observed that the electrical nature at the mineral-solution interface is controlled by pH of the solution, hence, hydrogen and hydroxyl ions seem to act as the potential determining ions for this mineral. The isoelectric point of almandite is determined to be at about pH 6.0, and therefore, the almandite surface would be negatively charged above pH 6.0 and positively charged below this pH. These results are correlated with the flotability obtained in the Haliimond tube test. The electrophoretic mobility and flotability measurements are also carried out as a function of concentration of typical cationic and anionic collectors at different pH values. The mobility and flotability are abruptly increased at the critical collector concentration which may begin to form "hemi-micelle". The variation of the isoelectric pH among several silicate minerals which were determined by electrokinetic measurements is discussed in terms of polarizing power of the metallic atoms in the minerals.
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