Ashed chips concentrate + HCl = Made a mess?

[VanMarco]

I added HCl to the concentrate of ashed chips (the usual deal, ash, concentrate with water). Did not remove steel with a magnet.
Last time I used nitric, but nitric is getting low, so i just added HCl and swirled around.
Solution turned dark green, most likely insta-reaction with CuO to form CuCl2.
now, i do know from reading other posts that it won't do like CuCl2 does as other metals are getting mixed in forming other chlorides.
All I need is to get rid of the bulk of the base metals somehow without using expensive nitric.
How do i tell if there isn't any more HCl left as it progresses dissolving metals? or at least, how could i test if it's "low" on HCl?
My plan was to eventually replace the solution with fresh HCl once spent. Not sure if bubbling air would achieve anything.
Simple question. Did I make a mess?

 

[eaglekeeper]

Hydrochloric acid will work, but it's going to be really, really slow. Removing the magnetics would cut down on the amount of time it would take. Using a bubbler will help by keep the solution moving.

Have you tried making home made nitric acid...it's extremely cheap.

 

[VanMarco]

But magnetics may have gold stuck to them. also, by slow are we talking geological times here?

 

[orvi]

Hydrometallurgy on powdery materials is always tedious and incomplete. Espetially speaking of incineration ashes, ceramic catalytic matrixes etc.
That is why all big guys use smelting processes, not leaching.
That said, from finely sifted material, you can effectively reduce the volume to 1/3-1/4 by just gravity separation (eg sluicing). That is also the way how to deal with them. Only then apply AR.

Seriously, deliberate pouring acids on things end up in messy situations and tedious recoveries like 95% of the time. Yet, people still do this

1. Collect the ashes by sifting, reduce the volume to 1/3 by sluicing or VERY CAREFUL panning.
2. Only then leach with AR. Better is to dry them and directly smelt, after magnetic stuff was removed. Adding some copper powder as collector with the charge may be beneficial. Then dissolve the obtained blob in AR.
3. Precipitate the gold...
4. Magnetic legs: hot lead or bismuth dipping - this will strip majority of gold (like 90%) of them, and concentrate it into easily cupelled metal alloy. Then cupel this and you have precious metals. Very little waste produced, which is nicely contained and eventually recycled (lead/bismuth). Whole process take like 3 hours including the cupelling stage.

 

[VanMarco]

yes, I already did the carefully panning thing, hence, concentrate. it's not much material. I thought it was best to remove most base metals before doing AR, especially giving the fact i do have tin and lead present in there.

 

[VanMarco]

Now, i did officially make a mess.
I removed the solution, added water, and a giant mass of white precipitate formed.
Both the solution and the rinse tests negative for gold at least. but what's getting trapped in the white stuff.. I don't know.
I suspect PbCl2. Soluble in HCl, insoluble in water
What could it be?

 

[FrugalRefiner]

Sounds like CuCl.

Dave

 

[VanMarco]

Well, knowing on the le chantelier's principle, i should have rinsed with HCl and not water

 

[VanMarco]

Update. I added fresh HCl, and it turned from light green to dark olive green, just like that CuCl2 guide on this forum. it is bubbling slowly.
My mom pointed out something obvious. Why didnt you take out the iron pins, it seem they are wasting a lot of reagents, when most of the gold dust is at the bottom of the beaker.
Is it true that the gold on steel pins from chips is litle to none?

 

[Martijn]

The copper chloride leach is never wasting reagents, only creating more copper chloride.
When you put iron in copper chloride, you cement out the copper, putting iron in solution, which is a pickle solution to etch curcuit boards (leaving the copper traces)

Leaving you with a copper- and iron chloride leach. All you have to add is air and a bit of HCl every now and then.

About gold being thin on iron, I can't confirm, that depends on the application I guess.