arthur kierski
Well-known member
I need pure rhodium to make plating solutioons--- i obtain rh from copper wires plated with gold and rh over it-or plated with silver and rh over it-----when i obtain these rh flakes mixed with gold flakes,i put these flakes in ar---the gold goes to solution and the rh flakes stay as rh----the gold solution is not transparent,and i suspected ,that lead chloride was present---i added h2so4 to the gold solution and it became translucid ,with lead sulphate precipitated(yellow powder)--then the usual metabisulfite to precipitate the gold----Where this lead impurity appeared from??>the rh plated with silver underneath,i add hcl,and precipitate silver chloride --then i clean the rh flakes with hot water and or nh4oh to clean for lead,and nh40h to dissolve any silver chloride left behind in the flakes----is there another way to separate rhe gold from rhodium? is there another way to separate the silver (as a chloride ,from the rh? i think that i do a good work,but i suspect that is not so good---and from where the lead appears in the rh plated wires? i do the first attacck on the wire with nitric acid(sometimes,twice nitric acid----- please ,pardom me if you did not understand this thread----my english is not native----but the idea,is what i wrote------In resume,how to obtain pure rhodium from rh plated wires?
Arthur
Arthur