problems in recovering of pure gold from 10 karat gold by ar process

[gambit2006]

10 karat gold rings contains diamonds. so i used ar to remove diamonds.
then i treated remains with repeated ar additions.
then i added urea and filtered solution ,i added gold reagent to ppt pure gold.
but i did not get full recovery. please help.

 

[anachronism]

Hi there

A lot more information is needed please. Can you explain what chemicals used in each step along with quantities. Some pictures would also be a bonus.

Nobody can actually give you any proper advice based upon the limited info provided so far, it would just be guesswork which doesn't help.

 

[4metals]

When performing a stone removal on 10 karat, often nitric and distilled water will break up the alloy sufficiently to loosen the stones so they can be separated. This is not true of higher karat or mixed karat.

Aqua regia alone on the first pass often will dissolve enough of the metal to allow the stones to separate as well but you will have chunks of gold which are encrusted with silver chloride.

Review this thread for a method to recover this silver encrusted gold. http://goldrefiningforum.com/phpBB3/viewtopic.php?f=85&t=22228

There's a lot of good stuff in the library!!!!

 

[Topher_osAUrus]

Why did you go straight AR first?

If I couldn't inquart because of diamonds, I would have went with a nitric treatment first on 10k instead of AR...silver chloride isn't reslly that fun..

 

[gambit2006]

10 karat gold rings contains diamonds. so i used ar to remove diamonds.
then i treated remains with repeated ar additions.
then i added urea and filtered solution ,i added gold reagent to ppt pure gold.
but i did not get full recovery. please help.

thanks for the information.but the question remains.i am not getting full recovery of expected pure gold.i am getting only 90-95% of pure gold from expected quantity.i have checked the solution with stannous chloride.the solution does not contain any gold.where did i go wrong?

 

[anachronism]

How did you calculate the expected return of gold? I note that you still didn't provide any further information. There may be some good people on here but we are not clairvoyant.

 

[FrugalRefiner]

I don't know what the regulations are where you live, or how well they're enforced. In the US, karat gold used to be allowed to be up to 1/2 karat below what it was stamped. If there was solder used on the piece, another 1/2 karat was allowed. So an item with solder stamped 10K could be as low as 9K. Of course, some manufacturers, especially small ones, would "cheat" a bit more. That can add up to the difference you're experiencing.

I don't know if that's actually the problem, but when I buy karat gold, I always base my offer on one karat below what it's stamped.

Dave

 

[Barren Realms 007]

10 karat gold rings contains diamonds. so i used ar to remove diamonds.
then i treated remains with repeated ar additions.
then i added urea and filtered solution ,i added gold reagent to ppt pure gold.
but i did not get full recovery. please help.

thanks for the information.but the question remains.i am not getting full recovery of expected pure gold.i am getting only 90-95% of pure gold from expected quantity.i have checked the solution with stannous chloride.the solution does not contain any gold.where did i go wrong?

How did you calculate what your gold recovery would be? Did you account for subtracting the weight of the diamonds?

 

[4metals]

thanks for the information.but the question remains.i am not getting full recovery of expected pure gold

You are not getting the answers you need because you are not providing the information on your processing. Did you leach the silver chloride encrusted bits in an ammonia solution? We are not with you there to see what you did so we have to go by your answers. So if you want to know what went wrong you need to give details of your process.

Generally with stone removal it is near impossible to know what your yield should be because it is never melted to attain a homogeneous sample before processing. Often pieces of lower karat are mixed in or even pieces of gold filled. Stone removal is paid on outturn, the gold that comes out after refining. After you subtract out the weight of the stones recovered and the platinum mounts that do not dissolve and remain after you clean up the insolubles, then the gold recovered weight, divided by the start weight minus the insolubles, equals the percentage gold in the lot.