Influência do tipo de espumante na prevenção à coalescência das bolhas

Abstract

One of the main functions of frother reagents used in flotation is to contribute to the stability of the bubbles size, especially in the pulp zone. The frother causes a waterproofing effect which hinders the coalescence phenomena responsible for the increase in the bubbles size. In this study it was investigated the influence of the type of frother in the control of the coalescence. It was used the three most common types of frothers: pine oil, polyglycol ether and metilisobutilcarbinol (MIBC). The determination of the bubble size was made using the adapted HYDROMESS system. Microflotation tests were performed with fines of graphite. MIBC is more efficient in preventing coalescence. The critical concentration of coalescence (ccc) was achieved with only 20 ppm. From this concentration of MIBC the average bubble size was stabilized at 2.2 mm. The best results of flotation were also obtained with MIBC what is probably related to more efficient control of coalescence.