Identification of precipitate

[AUH-R]

Hi all,

I hope everyone is well?

After the success of my fibre CPU Au recovery and processing I decided to process some of my ceramics. I have processed 21 Pentium 486's minus the lids.

I'm just going through my boil washes, I'm on my 3rd, before I go to my HCL boil wash I was wondering if anyone knew what the sand like precipitate was?



Thanks & best wishes,
AuH-R

 

[glondor]

The sandy clumpy stuff on the right is your gold. The puddly bronzy yellow brown stuff is???? It May wash out with the HCL wash. Keep washing and see.

 

[Smack]

You could use a snuffer bottle to pick up the gold, they are used in prospecting.

 

[Lino1406]

CuCl

 

[Marcel]

Dont forget to post the yield, just for the records...

 

[AUH-R]

CuCl

Thank you, that makes perfect sense.

Dont forget to post the yield, just for the records...

I won't, hopefully I will get it done this week if it ever stops raining!.

Best wishes,
AuH-R

 

[butcher]

The lighter brown almost looks like rust or iron oxides,

 

[jeneje]

The gold looks real dark in the pic, are you going to refine again? Looks like a lot of drag down.
Ken

 

[AUH-R]

The gold looks real dark in the pic, are you going to refine again? Looks like a lot of drag down.
Ken

Yes, this was just a recovery run using Sam's dirty AR method. Next batch I'm going to try the normal HN03 route as I feel having tried the dirty AR process it does not really have any benefits that I observed.

Best wishes,

 

[AUH-R]

The weather was nice when I returned from work today.

CuCl it was, as soon as I boiled with HCL solution turned green and it all disappeared.

Au after washing.


Au after Drying.


Weigh in 3.03g without lids, not sure if I will get 0.7g from 21 lids. Lids are outside soaking in some HCL, will process them in a couple of weeks.

 

[trashmasters]

Good looking GOLD powder,,... Now let us see the BUTTON.... Good Job.

 

[AUH-R]

486 bottoms have been processed. I yielded .98g from 21 processors. Total = 4.01g/21= 0.1909g average Au per chip.

 

[butcher]

Iron will also dissolve in HCl and give a green color, a better test to see if the precipitant was copper or iron would be to test the green solution, potassium ferro-cyanide can be used to test for iron in solution (see Hoke's book page 100), ammonia can be used to test for copper solutions (see page 99 in Hoke's book).

Iron can be like fools gold it can look like gold in solution or its other compounds.
Iron can also look like copper in solution.
The best way to identify. is to test for it.

 

[Gratilla]

A quick check would be the smear test:

Put a few grains of the brown stuff on a hard surface. Place the bowl end of a spoon on top.
Press down hard and smear. If it crunches and leaves a brown powder, it isn't gold (probably iron(iii) oxide/hydroxide).
If you get a yellow smear, you have the real thing.