| The process of dissolving the TiO2 carrier of the spent Pt/TiO2 denitration catalyst by acid-dissolving method and further enriching and recovering platinum was studied. The results show that the dissolution rate of TiO2 carrier by 20% HF+30% HCl can reach 95%, and the metal platinum is basically not dispersed. The effects of HF concentration, reaction temperature, time, and liquid-solid ratio in the mixed acid on the dissolution rate of the carrier are systematically studied. Under the optimized conditions of 20% HF+30% HCl as solvent, reaction temperature of 95℃, reaction time of 3 h, and liquid-solid ratio of 10:1, the dissolution rate of the titanium support reached more than 95%. For the dissolved enrichment, the traditional ammonium chloride repeated precipitation method is used for platinum refining and purification. The purity of sponge platinum is ≥99.95%, and the product quality is stable. |
