Sediment in nitric

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warmgold

Member
Joined
Oct 21, 2017
Messages
19
Hello to everyone, I did my first nitric bath with some milled gold ores.
soaked for two days in HCL (32%) with no added water. The acid workt well, a lot of iron got dissolved. Then soaked for two days in water.
Next I put the ore in a nitric solution (about 25/30%).
I leave it soaked for 48 hours and the acid is slightly yellow/orange, and there is a sediment on the ore .
What is it?
Do you think two days is enough to make the acid to work so I can going on with AR bath?
The temperature is getting low in these days, about 18/13 degrees C

The sediment is orange red as in photo, it will not dissolve in acid. But is the acid that "created" it...
 

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I believe there should have been a “roasting” or burning step between the water bath and the introduction of nitric. This will remove residual HCL. You may have already made A/R. Check your nitric solution for gold before discarding it.
However, ore is not my thing and others here are far more experienced then I.
 
Lino1406 said:
If I had an ore in the milled state, panning looks a good starting point

I'd certainly not be throwing acid all over it without knowing what's in it.
 
Thanks to everyone!

I tried the separation by gravity but the ore must be milled more (completely to extrafine powder) because most gold will be lost if not...I have not such a mill right now

The ore is composed most of quartz, matrix(micaschist), some altered iron(like pirite), mica, copper silver and gold

Morris
 
anachronism said:
Lino1406 said:
If I had an ore in the milled state, panning looks a good starting point

I'd certainly not be throwing acid all over it without knowing what's in it.
warmgold said:
Thanks to everyone!

I tried the separation by gravity but the ore must be milled more (completely to extrafine powder) because most gold will be lost if not...I have not such a mill right now

The ore is composed most of quartz, matrix(micaschist), some altered iron(like pirite), mica, copper silver and gold

Morris

I think Jon is stating this due to the possibility of arsenic and other nasties being present in ore.
 
snoman701 said:
anachronism said:
Lino1406 said:
If I had an ore in the milled state, panning looks a good starting point

I'd certainly not be throwing acid all over it without knowing what's in it.
warmgold said:
Thanks to everyone!

I tried the separation by gravity but the ore must be milled more (completely to extrafine powder) because most gold will be lost if not...I have not such a mill right now

The ore is composed most of quartz, matrix(micaschist), some altered iron(like pirite), mica, copper silver and gold

Morris

I think Jon is stating this due to the possibility of arsenic and other nasties being present in ore.

Thank you Sno,
I don't know if arsenic or other is present in the ore in minimal quantity , there could be some problems with the nitric or with AR?

Morris
 
Unless you know what your material consists of, you will not know how to process it safely. The only method applicable without assay is gravimetric recovery of free milling gold. Any methods that apply heat, such as roasting, or add chemicals, such as leaching, can easily liberate toxic fumes, some of which can be difficult to detect without proper equipment.

Time for more coffee.
 
galenrog said:
Unless you know what your material consists of, you will not know how to process it safely. The only method applicable without assay is gravimetric recovery of free milling gold. Any methods that apply heat, such as roasting, or add chemicals, such as leaching, can easily liberate toxic fumes, some of which can be difficult to detect without proper equipment.

Time for more coffee.


Thanks for the advice Galen, and yes time of a lot of coffee :mrgreen:

Anyway I took a bit of the ore nitric solution and put it in another basin, then add a coin.
The coin solution got orange/black/dirty in one day so I assumed the nitric acid on the ore is still active and already done the work. (after 4 days of bath the solution was the same light yellow as the first day, as the photo on the top of the topic)

I then washed the ore and put it in a basin, added 4 part HCL 33% and 1 part nitric 52%.
Reaction was quick, solution came dark orange and cloudy. Next day a new layer precipitated on the top of the ore again (looks like jelly somehow, and will not go IN solution when stirring )
Is this a problem? Should I keep this precipitate?

Thanks again for your knowledge guys

Morris
 
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