ABSTRACT

Phosphate ores are rarely utilized without being processed into other physical forms; approximately 80% are converted into phosphoric acid by dissolving with sulfuric acid, and 15% are converted into phosphorus by thermal reduction before being utilized as raw materials for various organic and inorganic substances. The rougher concentrate in the phosphate flotation is the apatite mixture that is floated with a fatty acid collector and that still contains more than 10% silica. The flotation method has been widely used for recovering phosphate from the phosphate ores of marine sedimentary origin. The major impurity in these phosphate ores is silica, but a conventional two-step process of flotation using tall oil fatty acid as collector for apatite and tallow amine as collector for silica was successful in removing the impurities. Francolite acts similarly to apatite in flotation treatments and differs from apatite only in chemical composition; namely, the phosphate ions of apatite are partially substituted by carbonate ions in francolite.