rhodium sulphate solution contaminated with copper or and silver

i made a quality test ,and the rh plating solution gave bad results---the pieces tested had a burnt aspect----this signifies metalic impurities like copper,silver or lead----can i eliminate these metals from the solution? or not---if not,i have to recuperate the rh by cementing it with zinc powder-----and begin the process of making rh sulphate plating solution from the beginning------- thanks for any information ------------------------------------------------------------------------Arthur Kierski

Arthur if you use zinc won’t it drop any silver copper etc along with your rhodium, I’m far from an expert on PGMs so perhaps wait for someone who knows a lot more than me :shock: :lol:

Nickvc,i think that i misled you and others in my thread---what i wanted to say is:i made a rh sulphate solution,and found out that this solution was contaminated with copper and other ions(like lead,iron nickel)---------- from this finding i have 2options-----the first is to find a chemical ,---to precipitate these ions out of the rh sulphate solution ---------the second solution(unfortunatelly) was to cement out (precipitate) all these metals impurities,including rhodium ,and begin the production of rhsulphate solution from the beginning---clean the rhodium from the impurities and then ,fuse in a furnace with nahso4 ,etc,etc-----i have an idea of how to eliminate the metalics impurities from the rh sulphate solution----but was asking some member of the forum to pass their ideas ,or ways to eliminate the impurities-----thanks for your reply to me---this gave me the oportunity to correct my previous thread----------------------------------------------------------------------------------------------------------------------------------------------------------Arthur Kierski

Platdigger,i have sent to you a private message----regards--Arthur Kierski

Please tell me how can remove silver and lead from rhodium solution

I assume this advice from Lou may help as copper and silver salts dissolve in ammoniac:

Easiest just to add lye or ammonia until pH 7.5, give it a good boil, filter the Rh hydroxide and re-use.


Lou