# urea in pgm solutions



## arthur kierski (Apr 13, 2008)

i noticed that some people are against using urea to kill the nitric acid from ar solutions. does urea locks the pgm in the solution? i am asking because this past week it happened to me and if it is true i might have l lost kilos of pgm in the past 3 years
would like to hear from your experiments--thanks-Arthur


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## Irons (Apr 13, 2008)

If you put your spent solutions in a stock pot, the Iron will precipitate any precious metals that are there.
You should never pour them down the drain because they may contain toxic compounds and may damage the sewer system.

PGMs like to complex with Ammonia and Ammonia like compounds. UREA is one of them.

I suspect you did lose some if you threw the solutions away.

Steel wool is cheap and will scavenge any PGMs in solution.


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## arthur kierski (Apr 13, 2008)

thanks for you quick reply -as always your common sense helps me.
pgm complex with urea and becomes dificult to extract all the pgm at once.i trow out the spent solution after i neutralize to ph 7----have not other way----now i am going to trow it after leaving to rest and precipitate with stell wool to see if any pgm was left behind.
thanks once again


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