Experimental research on the pressure oxygen leaching rhenium of waste platinum-rhenium catalyst with low acid

Abstract

Experimental material was the waste platinum-rhenium catalyst; X diffraction was used to characterize the material, and the results showed that the main phase of the waste platinum-rhenium catalyst was Al2O3. The process of rhenium pressure oxygen leaching in platinum-rhenium catalyst with low acid was put forward. The effects of leaching pressure, leaching temperature, leaching time, initial acidity of sulfuric acid and liquid-solid ratio on the leaching rate of rhenium during leaching were investigated in this paper. The results showed that the initial acidity of sulfuric acid had a significant effect on the leaching rate of platinum and rhenium. As the acidity increased, the leaching rate of platinum and rhenium also increased, and the leaching rate of carrier Al2O3 also increased. The experimental results show that the leaching of the optimal process conditions were as follows: leaching pressure 5 MPa, leaching time 3h, leaching temperature 140 °C, the initial sulfuric acid concentration 10%, liquid-solid ratio 4:1, mixing speed 350 rpm. Under these conditions, the leaching rate of rhenium and platinum was 98.11% and 83.59% respectively, and the slag rate was 75.56%. In order to prevent platinum from dispersing, ferrous sulphate was added at the end of the leaching process to reduce the platinum into the leaching residue. This process has the advantages of simple operation, high rhenium leaching rate, less impurity elements in the leaching liquid and low acidity, etc., which can provide reference for rhenium extraction from the waste platinum-rhenium catalyst.