Abstract: The raffinate acid obtained from the production of wet-process phosphoric acid for clean and efficient utilization is innovatively used in the flotation of phosphate ore. The flotation concentration with the P₂O₅ grade of 29.73%, the MgO grade of 0.78% and the P₂O₅ recovery of 88.55% is obtained under the condition of stable grinding fineness, collector dosage, pH after the closed-circuit flotation where the raffinate acid completely replaces the sulfuric acid. The raffinate, whose dosage is much lower than sulfuric acid, is used as pH regulator for reverse flotation of phosphate ore, which provides a new idea for recycling raffinate in phosphate mining enterprises.