I dissolve the catalyst in Aqua Regia solution. after finishing the work :
I add zinc to it. The reaction is highly calorific but does not precipitate
When I add sodium bohydride, nothing precipitates, and when I add more, a white jelly-like substance precipitates.
When I add aluminum to it, the reaction is very hot, but I have a black and purple deposit.
Exactly how should I separate palladium, platinum and rhodium from the solution.
Rhodium is not important to me right now. How do I separate platinum and palladium from Aqua Regia solution?
I think your Aqua regia is to strong or too much for the amount of PGM's , also using pool acid in place of proper HydroChloric acid is counter productive . Use as little as possible acid and pretreat the Catalyst material in a Hydrogen atmosphere to get rid of all Oxides . Try a different method of leaching the PGM's , there are many available
hello Johan Loots
It is true that I use strong Aqua Regia. Because when I use the weak type, a lot of precious metals do not come out.
I have found two methods that are English articles and are valid and citationable. One method is with Aqua Regia and the second method is hydrochloric acid and hydrogen peroxide. In the second method, it is stated that platinum will not be extracted. That's why I chose Aqua Regia In both methods, it is said that the catalysts should be boiled in solution up to 90 ° C for 3 hours !!!
If you can teach me how to neutralize the nitric acid in the solution so that only the chloride solution remains, I think my problem will be solved. When I deposit metals with aluminum, the problem is somewhat solved, but materials are made that slow down the filtering.
Can I remove palladium directly from the solution using DMG? Then remove the platinum using ammonium chloride? Next, how do I remove the rhodium?
Your guidance is appreciated volume_up content_copy share star_border
اطلاعات بیشتر درباره aqua
i use 65ml Hcl 12M and 8ml Hno3 15M
Hi Ali,
Share with us a bit more information...
What kind of catalysts are you working on? Car autocatlysts?
What reagents are you using?
What is the amount of each reagent used?
What was your leaching process?
Get the book by C.M Hoke , on refining Precious metal wastes .