A method for removing impurity lead from rhodium-iridium displacement slag
By reacting EDTA solution with rhodium-iridium replacement slag, the problem of efficient and stable removal of lead from rhodium-iridium replacement slag was solved, achieving efficient removal of lead and low loss of precious metals, simplifying the process flow, and making it suitable for the platinum group metals refining industry.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 金川集团铜贵股份有限公司
- Filing Date
- 2026-04-10
- Publication Date
- 2026-07-24
AI Technical Summary
In existing technologies, the lead removal effect in rhodium-iridium replacement slag is unstable, the lead removal rate is low, and the loss of precious metals is serious, which cannot meet the requirements of industrial production.
EDTA solution was mixed with rhodium-iridium displacement residue, with the solid-liquid ratio controlled at 1:5. The mixture was heated to 85-90℃ and kept at a constant temperature for 1.5-2.5 hours to complex lead with EDTA. The mixture was then cooled and separated to obtain lead-free filtrate and lead-free residue. Finally, platinum and palladium were recovered by chlorine gas and polyvinyl alcohol.
It achieves efficient and stable lead removal with a lead removal rate of ≥78%, low precious metal loss rate, simple process and compatibility with existing processes, and is easy to apply in industrial applications.
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