In domestic copper hydrometallurgical plants that adopt the solvent extraction-electrowinning process, alarge quantity of copper extraction raffinate containing ferric ions is typically discharged in an open⁃circuit manner tomaintain the acid-iron balance in leaching and hydrometallurgy systems for low⁃grade copper ores, indirectly leading tothe loss of metallic iron. To address this issue, this study investigates the synthesis of ferric phosphate dihydratefrom raffinate through an iron powder reduction-impurity removal-ammonium phosphate process, thereby alleviatingthe burden on environmental treatment systems while recovering valuable iron from the raffinate. The study focused onthe effects of impurity removal reagent dosage on impurity removal efficiency, along with the influence of the dosingratios of n（Fe）∶n（P）∶n（H₂O₂）, washing conditions, and aging phosphoric acid concentration on the product quality offerric phosphate dihydrate. Results show that optimal impurity removal is achieved under the conditions of excess ironpowder, 1.40 g/L sodium hydrosulfide, and 8.00 g/L of sodium carbonate（adjusted to pH 5.83）. A high⁃quality ferricphosphate dihydrate product can be synthesized under the conditions of n（Fe）∶n（P）∶n（H₂O₂）dosing ratio of 1∶1.05∶0.65, double washing with deionized water, and aging phosphoric acid concentration of 0.03 mol/L.