Urea to remove the excessive nitric

[kjavanb123]

All,

I was reading the forum archive, and it says somewhere, using Urea to remove the excessive nitric in gold bearing solution. can this be used in PGM refining, to remove the nitric instead of heating to syrup?

Thanks
Kev

 

[Barren Realms 007]

Yes.

 

[shyknee]

Avoid if possible. Although it does work .
You should research how to use it.

 

[nickvc]

From what I can remember if your trying to get high grade PGMs you need to precipitate them from a concentrated solution. I could well be wrong as PGMs have never been of much interest to me in refining,recovery definitely refining no,far to complicated for my simple brain

 

[shyknee]

From what I can remember if your trying to get high grade PGMs you need to precipitate them from a concentrated solution. I could well be wrong as PGMs have never been of much interest to me in refining,recovery definitely refining no,far to complicated for my simple brain

you are right. I was only thinking gold solution . For platinum group boiling to concentrate is the recommended way to go

 

[Harold_V]

For platinum group boiling to concentrate is the recommended way to go

No---it's not. Boiling is a HUGE mistake. Solutions should not be boiled for concentration, for values are lost in the process. That includes gold chloride.
It would be a service to others if when we speak of evaporation that we not call it "boil". That sends the wrong message. To evaporate, one heats the solution at a low level, always below a boil.

Harold

 

[shyknee]

Sorry Harold
Wording is so important my mistake

 

[Oz]

Harold is so correct in chastising us all on this. I am guilty of using the phrase “triple boiling” myself. I have seen it written that way in several old books and it is repeated all too often and is incorrect. Any member that has been here for a while knows that when they see this phrase that you are not supposed to take your solution to an actual boil.

However we all need to be cognizant of the fact that a newcomer may take these words literally so we should be more careful than others have been in the past by describing it properly. It is a triple evaporation that is performed. Let us all put the effort into correcting this and speaking with clarity.

 

[dtectr]

Harold is so correct in chastising us all on this. I am guilty of using the phrase “triple boiling” myself. I have seen it written that way in several old books and it is repeated all too often and is incorrect. Any member that has been here for a while knows that when they see this phrase that you are not supposed to take your solution to an actual boil.

However we all need to be cognizant of the fact that a newcomer may take these words literally so we should be more careful than others have been in the past by describing it properly. It is a triple evaporation that is performed. Let us all put the effort into correcting this and speaking with clarity.

thanks for the reminders - Those of us with less experience, like ME, get overanxious & think that "more is better" or in this case, "more heat is better". It helps to be reminded.

 

[lazersteve]

I would discourage the use of urea for removing the nitric form PGM solutions. Use less nitric in the beginning and you won't have to resort to adding more impurities and bad actors into the solution.

Short cuts when refining PGMs lead to problems.


Steve