Miniaturized application of 3D‐printed large‐flow microreactor in extraction and separation of platinum, palladium and rhodium

Abstract

AbstractProblems of long extraction time, large footprint, low single‐stage extraction efficiency, and complicated production processes in solvent extraction equipment in recycling of modern industrial precious metal waste liquids are addressed and application of miniaturized equipment to hydrometallurgy is proposed in this study. A 3D‐printed multichannel microfluidic reactor will likely replace traditional extraction equipment. The reactor was applied to experiments concerning tributyl phosphate extraction and separation of platinum, palladium and rhodium precious metal ions in a hydrochloric acid system. Results showed that, under the conditions of a ratio of 1:1 and a flow rate of 192.5 mL min‐1 (processing capacity of 1.5L h‐1), the extraction rates of platinum and palladium are 84.26% and 96%, and the separation coefficient is βPt/Rh and βPd /Rh is 132.35 and 753.5,moreover, the optimized extraction rate of platinum and palladium in the reactor increases by 2% and 1%, respectively. Hence, the extraction effect of this reactor is better than conventional industrial single‐stage extraction (extraction time 12min, platinum extraction rate 87.43%, palladium extraction rate 90.86%, separation coefficients βPd/Rh and βPt/Rh are only 65.3 and 45.7). In summary, compared with conventional extraction, microreactor extraction can increase the separation coefficient, shorten the extraction time, and the total processing capacity can reach the industrial production level. In addition, this study also discussed the influence of microreactor structure optimization on the extraction effect. © 2020 Society of Chemical Industry