Effect of rhamnolipid biosurfactants on performance of coal and mineral flotation

The effect of a concentrated rhamnolipid biosurfactant (purity > 97%) produced by Pseudomonas aeruginosa MA01 on flotation performance of coal and minerals was studied and compared with those from synthetic flotation reagents in both single and mixed systems. Results of phosphate flotation tests showed that phosphate content in the floated product decreased by rhamnolipid concentration. However, final recovery of phosphate at appropriate dosage of reagent was insignificant. This could be ascribed to the increase of iron recovery to final concentrate likely due to collecting action of rhamnolipid for iron minerals. In coal flotation, the increase of rhamnolipid concentration in mixture with pine oil reduced both ash content and coal yield of concentrates. In desulfurization of a sample iron concentrate using reverse flotation, rhamnolipid addition successfully decreased the sulfur content of the iron concentrate. The flotation responses of the studied sample ores showed that rhamnolipid can be used as a promising frother or co-frother in mineral processing practices.

► A rhamnolipid biosurfactant produced by a Pseudomonas aeruginosa MA01 strain.
► Rhamnolipid was characterized in terms of its structural and surface properties.
► Effect of rhamnolipid on flotation performance of some sample minerals was studied.
► Results showed that rhamnolipid could be successfully applied to mineral flotation.