Reagents in igneous phosphate ores flotation

The role of reagents utilised in igneous phosphate ores flotation is reviewed. Fatty acids soaps derived from different vegetable species are utilised as collectors. Less expensive species, such as rice and soybean bran oils replaced successfully the more expensive tall oil as the source for the apatite collector. Synthetic collectors such as sarcosinate and sulphosuccinate are also employed. The collector species plays also the frother role. Corn starch is the gangue depressant. Less pure starches, with oil contents equal to or higher than 3%, may be utilised without the risk of suppressing the froth. Actually they may act as a froth controller due to the fact that the fatty acid soap that plays the frother role is an ionic species, generating thus a voluminous froth. Non ionic ethoxylated surfactants may also be used to control the surface tension of the system. Barite, when present, may be either pre-floated with cetyl-stearyl sodium sulphate or depressed, in the fine apatite flotation circuit, at pH 12.