Recovery of Platinum from Spent Petroleum Catalysts: Optimization Using Response Surface Methodology
Artikel i vetenskaplig tidskrift, 2019

The global yield of platinum (Pt) recovery from spent catalysts is about 30%. Pt recovery from spent catalysts is one of the most significant methods to reduce its supply risk and meet future demand. The current hydro-leaching processes always involve extremely high acidity (c(H+) > 6.0 mol/L), causing serious environmental issues and consuming large amounts of reagents. This paper studied the recovery of Pt from spent petroleum catalysts in a mild leaching solution (c(H+) = 1.0-2.0 mol/L). The HCl and NaCl were used as leaching agents, while H2O2 was used for oxidation of Pt. The leaching factors, including solid/liquid ratio (S/L), acidity, leaching temperature, and H2O2 usage, were studied. The leaching efficiency of Pt was 95.7% under the conditions of S/L of 1:5 g/mL, HCl of 1.0 mol/L, NaCl of 5.0 mol/L, 10% H2O2/spent catalysts of 0.6 mL/g, and temperature of 90 degrees C for 2 h. The leaching kinetic of platinum fits best to the Avrami equation. The apparent activation energy for leaching platinum was 114.9 kJ/mol. Furthermore, the effects of the operating variables were assessed and optimized by employing a response surface methodology based on Box-Behnken Design. The result shows that HCl concentration had the greatest impact on the leaching efficiency as compared to the H2O2 concentration and S/L ratio. Pt leaching efficiency was increased to 98.1% at the optimized conditions of HCl of 1.45 mol/L, NaCl of 4.55 mol/L, 10% H2O2/spent catalysts of 0.66 mL/g, and S/L of 1:4.85. The purity of Pt is over 90% by the reduction of iron powder.

leaching

spent petroleum catalysts

platinum recovery

kinetic analysis

response surface methodology

Författare

Yunji Ding

Beijing University of Technology

Huandong Zheng

Beijing University of Technology

Jiayi Li

Beijing University of Technology

Shengen Zhang

Beijing University of Technology

Bo Liu

Beijing University of Technology

Christian Ekberg

Chalmers, Kemi och kemiteknik, Energi och material, Kärnkemi

Zhuming Jian

Yunlong Country Platinum Cui Precious Metals Technology Co., Ltd.

Metals

2075-4701 (eISSN)

Vol. 9 3 354

Ämneskategorier

Kemiska processer

Annan kemiteknik

Energisystem

DOI

10.3390/met9030354

Mer information

Senast uppdaterat

2019-08-16