Effects of preparation conditions on performance of discarded biological oil as coal flotation collectors

Abstract

Discarded biological oil was modified under various preparation conditions to produce coal flotation collectors to replace traditional petroleum flotation collectors. Effect of alcohol-oil molar ratio, catalyst dosage, reaction temperature and reaction time on clean coal yield was investigated. The results showed that the flotation collectors made from discarded biological had higher clean coal yield. Through orthogonal and single-factor tests, the best modified parameters were obtained, at a temperature of 50°C, an alcohol-oil molar ratio of 8:1, a potassium hydroxide (KOH) catalyst of 0.5% and a reaction time of 2.5 h. The alcohol-oil molar ratio and catalyst dosage were the most important factors to influence the performance of the flotation collectors. Under optimal conditions, the coal flotation collectors had higher clean coal yield than ordinary diesel oil or kerosene, and clean coal ash was also lower. Coal ash and clean coal yield were 7.93% and 58.54% under biological oil flotation collectors, while coal ash and clean coal yield were 8.29% and 57.65% under diesel flotation collectors. [Received: February 7, 2013; Accepted: December 31, 2013]