Abstract: Process for treating by reverse flotation phosphate ores of the carbonate or silico-carbonate gangue type. It includes the steps of:(1) conditioning of the ore in a manner known per se with a product acting to depress the phosphate compounds,(2) treatment of the conditioned ore step (1) with a collector essentially comprising a phosphoric ester,(3) flotation of the carbonates, this leading to a flotation residue which contains the phosphate compounds and, if so required, in the case where the starting compound is of the silico-carbonate gangue type,(4) conditioning of said flotation residue by a cationic collector, the possibly present silicates being thus separated by flotation.The process permits benification of the phosphate ores by a treatment wholly carried out in sea-water.

Abstract: A process for recovery of phosphates in ores with silico-carbonate gangue:(1) overall flotation of the ore with a collector comprising essentially a phosphoric ester in an amount and under conditions capable of causing the silicate compounds to pass into the flotation residue, and in recovering a float product containing the phosphate and carbonate compounds.(2) conditioning the float product in an acid medium for a length of time sufficient to cause the flotation of carbonates, while the phosphates constituting the valuable product desired, remain in the residue.