Reverse flotation of sedimentary calcareous/dolomitic rock phosphate ore -An overview

The depletion of high-grade phosphate ol es is bringing about a search for a suitable, economically viable technique that cart process the abundant lo w-grade phosphate reserves. About 75% to 80% of the world's low-grade phosp hate reserves are associated with carbonate gangue that is not amenable to treatment by the simple techniques of physical separation. The processing o f sedimentary dolomitic/calcareous phosphate ore has numerous problems, inc luding similar surface properties of the carbonate and phosphate. Two-stage reverse anionic flotation of carbonates (dolomite/calcite) has appeared to be a promising separation technique for the removal of carbonates from sed imentarly rock phosphate. In reverse fatty-acid anionic flotation, the depr ession of phosphate mineral with orthophosphoric acid produces satisfactory results for calcareous as well as dolomitic phosphate ores from several lo cations of sedimentary origin.