Kinetics and leaching behaviors of aluminum from pharmaceutical blisters in sodium hydroxide solution
来源期刊：中南大学学报(英文版)2015年第12期
论文作者：WANG Chong-qing WANG Hui GU Guo-hua FU Jian-gang LIU You-nian
文章页码：4545 - 4550
Key words：aluminum; kinetics; leaching behavior; pharmaceutical blisters; sodium hydroxide
Abstract: A hydrometallurgical process was developed for recycling pharmaceutical blisters. Leaching aluminum from pharmaceutical blisters using sodium hydroxide (NaOH) solutions was investigated with respect to leaching behaviors and kinetics. A L9 (34) orthogonal design of experiments suggests that the most significant factor is NaOH concentration followed by temperature and leaching time. Factorial experiments demonstrate that the leaching rate of aluminum increases with increasing of the factors. The optimum conditions are temperature of 70 °C, leaching time of 20 min, NaOH concentration of 1.25 mol/L, liquid-to-solid mass ratio of 15:1 and agitation speed of 400 r/min. Under optimum conditions, the leaching rate is up to 100%, implying that aluminum and polyvinyl chloride (PVC) plastic in pharmaceutical blisters are separated completely. Kinetics of leaching aluminum is best described by the product layer diffusion control model, and the activation energy is calculated to be 19.26 kJ/mol.
WANG Chong-qing(王重庆)1, WANG Hui(王晖)1, GU Guo-hua(顾帼华)2, FU Jian-gang(符剑刚)1, LIU You-nian(刘又年) 1
(1. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;
2. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China)
Abstract:A hydrometallurgical process was developed for recycling pharmaceutical blisters. Leaching aluminum from pharmaceutical blisters using sodium hydroxide (NaOH) solutions was investigated with respect to leaching behaviors and kinetics. A L9 (34) orthogonal design of experiments suggests that the most significant factor is NaOH concentration followed by temperature and leaching time. Factorial experiments demonstrate that the leaching rate of aluminum increases with increasing of the factors. The optimum conditions are temperature of 70 °C, leaching time of 20 min, NaOH concentration of 1.25 mol/L, liquid-to-solid mass ratio of 15:1 and agitation speed of 400 r/min. Under optimum conditions, the leaching rate is up to 100%, implying that aluminum and polyvinyl chloride (PVC) plastic in pharmaceutical blisters are separated completely. Kinetics of leaching aluminum is best described by the product layer diffusion control model, and the activation energy is calculated to be 19.26 kJ/mol.
Key words:aluminum; kinetics; leaching behavior; pharmaceutical blisters; sodium hydroxide
