Development of in-situ electro-generated chlorine leaching and its application to the leaching of platinum. Issue 3 (4th July 2022)

• Record Type: Journal Article
• Authors: Kim, Min-Seuk; Kim, Rina; Chung, Kyeong-Woo; Lee, Jae-Chun
• Is Part Of: Geosystem engineering. Volume 25:Issue 3/4(2022)
• Page Start: 185
• Page End: 193
• Publication Date: 2022-07-04
• Subjects: electro-generated chlorine -- platinum -- leaching -- spent automotive catalyst -- recycling; Mining engineering -- Periodicals; Petroleum engineering -- Periodicals; Gas engineering -- Periodicals; Geology, Economic -- Periodicals; 620
• DOI: 10.1080/12269328.2022.2148758
• Languages: English
• ISSNs: 1226-9328

Abstract

ABSTRACT: An in-situ electro-generated chlorine leaching with a closed recycling unit of unconsumed gas was developed for precious metal dissolution and applied to the leaching of platinum from a spent automotive catalyst containing 0.13 wt% Pt. Cathodic current in a cathodic compartment of the chlorine generation cell reduces the unconsumed chlorine gas into chloride ions for further chlorine generation. The electro-reduction efficiency was 99.4% in alkaline 2 M NaCl solution, whereas 80.8% in 35% HCl solution at 0.62 mmol min −1 supply rate of unconsumed chlorine gas. The 98.3% platinum from the spent automotive catalyst leached without discharging the unconsumed chlorine gas into the air at 100 g L −1 solid/liquid ratio and 80°C in a 7 M HCl solution. Increasing the solid/liquid ratio to 400 g L −1 drastically decreased the leaching percentage to 16.5% in 90 minutes by possible adsorption of leached Pt to the porous surface of the automotive catalyst carrier.