Dry Ultrafine Grinding of Tourmaline Using Grinding Aids of Lower Alcohols

Abstract

The effect of lower alcohol aids on the ultrafine grinding of a tourmaline of a silicate mineral was examined by using a vibration ball mill with a laboratory scale. Lower alcohols used were methanol, ethanol and 1-butanol. All of the experiments were carried out by batch operation, and the change of the specific surface area of tourmaline with grinding time was measured by BET adsorption method. The results showed that the lower alcohols were very effective as grinding aid for ultrafine grinding of tourmaline and especially 1-butanol had the aid effect best. Through various measurements the surface of products ground with lower alcohol aids were found to exhibit hydrophobicity due to the chemisorption of alcohol molecules to the surface. The preferred effect of 1-butanol aid is attributed to efficient monolayer adsorption compared with methanol and ethanol of multimolecular layers adsorption.