Steve,

There are resins that would be pretty specific for nickel in a gold
solution.  The chelated resins (IDA or AP) would be suitable providing that
there are no other metal ions that have to be in solution.  The resin will
remove all cation metal ions and leave in sodium, potasium, and hardness
ions (at low pH).  

I haven't worked with gold solutions since the early 80's (was a microplate
guy) so I'm a bit out of date.  I assume soft gold is gold only with
potassium salts and I'm guessing that the pH is less than 5 but I don't know
off the top of my head anymore.  You would have to adjust the resin before
use to keep the exchange group compatable with the bath.

I could get you a ounce or so of resin to try on a small sample of gold.
You would have to prep the resin first before trying.  The resin will not
remove the gold as it pretty well locked in the cyanide complex.

The simplest test would be to prep the resin, take about 5 cc's of gold
solution, add about 5 beads of resin to the solution and mix for 2-3 hrs
(makes up for not using a column).  Check the nickel, gold, pH and other
parameters.  This should tell you if it will work.

I you want a sample, send me your bath analysis so I can be sure I know what
I'm talking about.

Bob Mesick


At 02:42 AM 1/14/97 CST, you wrote:
>------------------------------

>
>Date: Mon, 13 Jan 97 23:16:34 PST
>From: <[log in to unmask]> (Steve Sparkowich)
>To: <[log in to unmask]>
>Subject: Ni Resins for Gold Plating
>Message-Id: <[log in to unmask]>
>Content-Type: text/plain;
>               charset=US-ASCII
>
>Do any of you Gold electroplaters use an  ion exchange resin specific to 
>removing Nickel from a soft gold bath?  If so, I'm interested!
>
>[log in to unmask]
Remco Engineering (remco.com/home.htm)
Industrial Water and Wastewater Treatment Systems
San Luis Obispo, California  USA

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