A Critical Review on the Flotation Reagents for Phosphate Ore Beneficiation

Phosphate ore is the dominating natural resource for the production of fertilizers and phosphorous chemical products. Flotation is the most widely employed technique to enrich apatite and remove the impurities for the separation of the phosphate ore. The flotation reagents play an important role in this efficient separation of phosphate ores. In the last few decades, great progress has been achieved in the flotation reagents for phosphate ores. However, a critical review on this theme has rarely been reported in recent years. Thus, the goal of this paper is to critically analyze the published literature on the flotation reagents for phosphate ores, mainly ranging from 2010 to 2024, including the regulators, depressors, collectors, and frothers. Additionally, the interaction mechanisms between the reagents and mineral surfaces were analyzed. It is concluded that sulfuric acids and its derivatives play a leading role in the depression of phosphate minerals. Highly selective biobased depressants have become potential carbonate inhibitors. Additionally, the derivatization and synthesis of multi-functional compounds and identifying the biobased frothers are the main development trends of collectors and frothers. Overall, a high-quality concentrate with a 31.05% grade and 98.21% recovery at pH 5 was achieved using lecithin as an ecofriendly amphoteric collector and sulfuric acid as the depressor when the feed contained 24.49% P2O5, which was superior to other flotation indexes of similar phosphate ores. This review will help researchers to document knowledge gaps and provide a reference for the efficient and green beneficiation of phosphate ores in the future.