Green bioflotation of calcite using surfactin as a collector

Abstract

In this study, the collecting effect of the biosurfactant obtained from Bacillus subtilis on the flotation of calcite mineral was investigated. NMR and FT-IR analyses show that the obtained biosurfactant is similar to surfactin. It is known that surfactin is a biomolecule used in various industrial fields such as cleaning and cosmetics apart from mining. Surfactin is an amphiphilic molecule containing hydrophobic and hydrophilic parts. With this feature, the surfactin has the potential to be used as a collector in flotation. In preliminary tests, it has been observed that the surfactin floats calcite efficiently. Central Composite Design (CCD) method was used in systematic calcite bioflotation experiments. In the bioflotation test results in which the effects of solid ratio, pH and collector amount were examined, 80% calcite recovery was obtained. In order to compare the results of bioflotation and classical flotation, several calcite flotation experiments were performed with oleate under the conditions given in the literature. According to the results, the pH in bioflotation is close to the natural pH of the pulp and the bioreagent consumption is one-tenth of the oleate consumption. These data suggest that on an industrial scale, the bioreagent could be a strong competitor to oleate.