# Cinnabar?



## kjavanb123 (Apr 4, 2020)

Hi

Since the social distancing I took a hike in an old gold mining district and found this interesting quartz with iron oxide limonite.

Does it look if it has Mercury as the color resembles the Cinnabar I saw on Wikipedia.




Thanks
KJ


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## butcher (Apr 4, 2020)

Looks like it, can you smell the sulfur when you break it open?
Have you tried a streak test for a violet color?
Hardness test, and specific gravity?

Try powdering a small piece mix with a few drops of HCl and rub onto a clean oil-free copper penny, a positive for mercury would coat the penny in silvery color.


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## kjavanb123 (Apr 4, 2020)

Thanks butcher will give it a try and post the result.


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## Lino1406 (Apr 5, 2020)

Can be many things


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## kjavanb123 (Apr 5, 2020)

Thanks Lino, I will follow butcher advise to make sure what I have, busy with another project but once I test this spiceman I will post result.


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## Rick & Carrie (Mar 27, 2022)

kjavanb123 said:


> Hi
> 
> Since the social distancing I took a hike in an old gold mining district and found this interesting quartz with iron oxide limonite.
> 
> ...



The bottom of the sample is Hematite; an Iron Oxide that commonly contains gold.

The top half appears to be Orpiment or Realgar, both of which are arsenic minerals.

So with Iron and Arsenic as metals within the sample, I can easily say that piece of material represents what the primary ore of that region looks like, and that it was being mined for its gold content.

Here are a couple of videos that we created on the topic of gold ores.

We hope that they are helpful and informative.


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## kjavanb123 (Mar 29, 2022)

Rick & Carrie said:


> The bottom of the sample is Hematite; an Iron Oxide that commonly contains gold.
> 
> The top half appears to be Orpiment or Realgar, both of which are arsenic minerals.
> 
> ...




Thanks Rick. It is good to see you back on the forum. 

One thing I noticed in dried river beds in that region, or anywhere around it, there is gold in them, I haven't done large sampling yet. 

Will report my finding soon.


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## Rick & Carrie (Mar 30, 2022)

kjavanb123 said:


> Thanks Rick. It is good to see you back on the forum.
> 
> One thing I noticed in dried river beds in that region, or anywhere around it, there is gold in them, I haven't done large sampling yet.
> 
> Will report my finding soon.


You're welcome, and Thanks. 
I am glad to be back too.

Have your sluice or drywash box cons assayed when you get them.

I once assayed drywash cons from a Greenhorn in Arizona who ran some dessert sand through a drywasher.

It was almost all Black Sand with no visible Gold.

It assayed 8 oz per ton Gold.

... He asked if that was good.


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## kjavanb123 (Mar 31, 2022)

Rick & Carrie said:


> You're welcome, and Thanks.
> I am glad to be back too.
> 
> Have your sluice or drywash box cons assayed when you get them.
> ...



I have started a threat about this called '' placer rhodium". I was looking for PGM nuggets in the dried River bed merging from ophiolite mountains with lots of chromite mines. 


I took a very small sample from an inch of the surface in the middle of the dried bed not even at the bend or places where PMs are most likely found. 


I did an AR assay on the sifted sample and to my surprise got purple. 


I repeated the same sampling and assay from any other dried river in the area and got positive for gold but no traces of PGMs. 


So I am going to take a larger sample, maybe 15kg or more, sift it into coarse and fine sizes, run them in my DIY blue bowl, and lead smelt follow by cupel the concentrates. 


But based on the purple result from such a small amount of fine, I am guessing 10 or 15ppm even more is not out of reach. 


As you mentioned the cons also black sand and no visible nuggets. 


Thanks


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## Rick & Carrie (Mar 31, 2022)

kjavanb123 said:


> I have started a threat about this called '' placer rhodium". I was looking for PGM nuggets in the dried River bed merging from ophiolite mountains with lots of chromite mines.
> 
> 
> I took a very small sample from an inch of the surface in the middle of the dried bed not even at the bend or places where PMs are most likely found.
> ...


Nice. 

I would like to see the bead when you are done with your smelt.

Take note of the weight of the amount of cons smelted, as well as the weight of the bead produced from the smelt.

Divide the concentrate weight by 29.16gm. 

Cons weight ÷ 29.16gm = assay tons smelted.

Bead weight in milligrams ÷ assay tons smelted = amount of gold/silver per ton.

Each milligram of bead weight equals one oz per ton.

If you drop the bead in a hot solution of 9 parts water to 1 part nitric acid and let me know what color it turns, I can calculate its purity for an exact amount of gold and silver per ton of river sand concentrate.


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## Yggdrasil (Mar 31, 2022)

Rick & Carrie said:


> Nice.
> 
> I would like to see the bead when you are done with your smelt.
> 
> ...


Is that some imperial measurement, or a thing from experience, taking into account what happens during smelting and assaying?


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## Rick & Carrie (Mar 31, 2022)

Yggdrasil said:


> Is that some imperial measurement, or a thing from experience, taking into account what happens during smelting and assaying?


I am an assayer.
If the instructions are followed, we can calculate the amount of recoverable gold and silver.


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## Yggdrasil (Mar 31, 2022)

Rick & Carrie said:


> I am an assayer.
> If the instructions are followed, we can calculate the amount of recoverable gold and silver.


You did not answer my question, but I guess it is not metric.


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## kjavanb123 (Mar 31, 2022)

Rick & Carrie said:


> Nice.
> 
> I would like to see the bead when you are done with your smelt.
> 
> ...


Thanks Rick. I was planning to do just that. 

I will have some pictures of the process and the field.


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## Rick & Carrie (Mar 31, 2022)

Yggdrasil said:


> You did not answer my question, but I guess it is not metric.


Then I guess I am not understanding what you are asking.


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## Rick & Carrie (Mar 31, 2022)

kjavanb123 said:


> Thanks Rick. I was planning to do just that.
> 
> I will have some pictures of the process and the field.


Way cool. Looking forward to them.


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## goldshark (Apr 1, 2022)

29.16 grams is the Avordupois conversion for assaying. It goes like this; 2000 lbs. = 1 ton. 16 ozs. = 1 lb. 16 x 2000 = 32,000 ozs per ton. 29.16 grams per oz. . 32000 x 29.16 =933,120, or for shits sake, call it one million grams per ton. By assaying 1 assay ton (29.16 grams), for every milligram in your bead, is one ounce per ton material. Very precise scales are used for weighing, or for smaller beads, a set of spreaders (basically a micrometer), or a graduated lens will tell the quantity by size of bead.


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## Rick & Carrie (Apr 1, 2022)

goldshark said:


> 29.16 grams is the Avordupois conversion for assaying. It goes like this; 2000 lbs. = 1 ton. 16 ozs. = 1 lb. 16 x 2000 = 32,000 ozs per ton. 29.16 grams per oz. . 32000 x 29.16 =933,120, or for shits sake, call it one million grams per ton. By assaying 1 assay ton (29.16 grams), for every milligram in your bead, is one ounce per ton material. Very precise scales are used for weighing, or for smaller beads, a set of spreaders (basically a micrometer), or a graduated lens will tell the quantity by size of bead.


Thanks for the explanation and for covering the math.


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## jobinyt (Apr 1, 2022)

Except, if I'm not mistaken, you should us 14 ounces per pound - not 16 with precious metals.


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## campbellj46 (Apr 1, 2022)

jobinyt said:


> Except, if I'm not mistaken, you should us 14 ounces per pound - not 16 with precious metals.




The Troy oz, lb, tonne is used as an industry standard for buying and selling pure precious metals. 

The Troy standard isn't used for assaying ore samples. Once it's mined, smelted, and made into pure bars, rounds, ingots, etc, then it follows the Troy standard for buying and selling to the markets.


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## kjavanb123 (Apr 13, 2022)

Hi


I was able to collect the sample and take some pictures from a dried river and the hills around it that were mined for gold. 


Hills around the river are mostly extrusive igneous rocks. Here are some pictures of the surrounding hills. 









This was the vein that was mined for gold.


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## kjavanb123 (Apr 13, 2022)

This is the drainage that I took the sample from.



I collected 10.79kg (23.78 lbs) gravel from different spots, few inches from the surface. Here is the picture. 



This is my sifting process. The top sieve is 1mm mesh and the bottom is 60 mesh. 



Sifting produced two different sizes, coarse and fine. Pictures of those 2 sizes.






Now I will weigh the coarse and fine, wash and concentrate both, then weigh them, and finally smelt and cupel the concentrates.

Thanks
KJ


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## Rick & Carrie (Apr 13, 2022)

kjavanb123 said:


> Hi
> 
> 
> I was able to collect the sample and take some pictures from a dried river and the hills around it that were mined for gold.
> ...



The iron stained rock by the label in the second photo is classic of hard rock gold ore; when it's gold content is high enough to be worth mining.

We would like a sample of the reddish orange quartz vein just to the left of the dark streak in the second photo; also the photo with the wrapper label.

In the photo of the vein workings;
were they processing the placer like material under the shale cap, or were they crushing and tabling the shale cap for its Gold content?


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## kjavanb123 (Apr 14, 2022)

Rick & Carrie said:


> The iron stained rock by the label in the second photo is classic of hard rock gold ore; when it's gold content is high enough to be worth mining.
> 
> We would like a sample of the reddish orange quartz vein just to the left of the dark streak in the second photo; also the photo with the wrapper label.
> 
> ...



Hi Rick


I have done some AR assay on the iron stained quartz in the past with result positive for gold but never assay for the gold content. 


There was a massive quartz vein in the cavity under the shale, I believe they extracted and processed that for gold content most likely using smelting. 


There has been no work on the placer gold that I am working on now. 


Thanks 

Kj


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## Rick & Carrie (Apr 14, 2022)

kjavanb123 said:


> Hi Rick
> 
> 
> I have done some AR assay on the iron stained quartz in the past with result positive for gold but never assay for the gold content.



Why not??? 

Especially since the Gold content would be of prudent man rule status. 

One milligram of Gold per CC of solution will test positive with stannous chloride.

In a fire assay, 1 mg represents 1 oz per ton, and a fire assay requires 29.16 g of ore. 

So if you AR tested a small fragment and it tested positive, the ore is worth getting and processing.


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## kjavanb123 (Apr 14, 2022)

Rick & Carrie said:


> Why not???
> 
> Especially since the Gold content would be of prudent man rule status.
> 
> ...




Rick


I didn't fire assay thoss quartz rocks since I am focused on placer gold since nature already done the crushing and milling part.


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## kjavanb123 (Apr 26, 2022)

Updates


I finished concentrating on the coarse and fine sizes from that 10kg sample using my blue bowl. 


Coarse size part weighs 2.12kg (4.62lbs). 


Fine size part weighs 1.38kg (3lbs),


After concentrating their weighs are as following:


Coarse concentrate weighs 678g

Fine concentrate weighs 17g


Here is the picture of coarse concentrate and under the microscope these orange crystals. 






Since the fine size concentrate is much smaller in volume. I smelted that, by placing the concentrates at the bottom of the crucible then adding the Flux plus litharge flour mix. 


After cupeling completed I was left with a bead of lead and some oxides, I cleaned it with hot nitric acid and got this black bead which is insoluble in boiling nitric acid and weighs 0.54g



I am going to melt that bead with 20g of silver then dissolve in nitric to find out what this black bead is.


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## Rick & Carrie (Apr 26, 2022)

kjavanb123 said:


> Updates
> 
> 
> I finished concentrating on the coarse and fine sizes from that 10kg sample using my blue bowl.
> ...



It's been awhile,
but these are my calculations.

You started with a 17 gm sample.

An assay uses 29.16 grams of ore. Each milligram recovered equals one oz per ton.

So ... 29.16 ÷ 17 = 0.58299039 of an assay.

The bead weighs 0.54 GM.
0.54 × 0.58299039 = 0.31481481 mg

The bead turned black in hot Nitric Acid indicating a purity of 20% Gold.

So ... 0.31481481 × .20 = 0.06296296 oz tn AU.
0.47703704 oz tn AG

... Not exact but close.


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## kjavanb123 (Apr 26, 2022)

Rick & Carrie said:


> It's been awhile,
> but these are my calculations.
> 
> You started with a 17 gm sample.
> ...


Hi Rick

Thanks for your calculation. I wonder what the black bead is, I will try to smelt it with silver then part with nitric. 

Thanks and best regards
KJ


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## Yggdrasil (Apr 26, 2022)

Rick & Carrie said:


> It's been awhile,
> but these are my calculations.
> 
> You started with a 17 gm sample.
> ...


Your math is bit off I think.
0.54 g is 540mg and since he used less than a assay ton his percentage need to increase,
hence 540/0.58299039 is 926.26 mg?


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## Rick & Carrie (Apr 26, 2022)

Yggdrasil said:


> Your math is bit off I think.
> 0.54 g is 540mg and since he used less than a assay ton his percentage need to increase,
> hence 540/0.58299039 is 926.26



Agreed. Groggy and math doesn't work well.

0.18524 oz tn AU
0.74096 oz tn AG.


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## Rick & Carrie (Apr 26, 2022)

kjavanb123 said:


> Hi Rick
> 
> Thanks for your calculation. I wonder what the black bead is, I will try to smelt it with silver then part with nitric.
> 
> ...


I just told you it was an alloy of Gold and silver.


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## shadybear (Apr 27, 2022)

maybe you should think about cleaning up that chunk you have there before melting it nitric bath or sulfuric acid just to see what it looks like
cleaned up


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## kjavanb123 (Apr 27, 2022)

Rick & Carrie said:


> I just told you it was an alloy of Gold and silver.


Hi Rick

I was under assumption that silver alloyed with gold would dissolve in nitric. 

Also this was from fine size concs, I still have to smelt the coarse fine concs which is few hundred grams. Then I can say how much gold per ton. 

Thanks for the correction.


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## kjavanb123 (Apr 27, 2022)

shadybear said:


> maybe you should think about cleaning up that chunk you have there before melting it nitric bath or sulfuric acid just to see what it looks like
> cleaned up


This piece was left in boiling nitric then hot water so it is pretty cleaned up.


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## kjavanb123 (Apr 27, 2022)

By the way I was wondering if gold content is 20 percent of the alloy, wouldnt the alloy be dissolved in nitric and leave the gold as brown powder? 

I think the gold content should be a lot more than 20 percent in the alloy to not dissolve in nitric. 

Thanks


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## Geo (Apr 27, 2022)

kjavanb123 said:


> By the way I was wondering if gold content is 20 percent of the alloy, wouldnt the alloy be dissolved in nitric and leave the gold as brown powder?
> 
> I think the gold content should be a lot more than 20 percent in the alloy to not dissolve in nitric.
> 
> Thanks


You can slowly leach 10K in hot nitric acid. It is very slow but very doable. 10K is 41% gold.


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## kjavanb123 (Apr 27, 2022)

Geo said:


> You can slowly leach 10K in hot nitric acid. It is very slow but very doable. 10K is 41% gold.


Thanks Geo. I tried to dissolve that bead in boiling nitric acid for 40 minutes but nothing happened. 

The only bead I have seen with similar look was 7.5g Palladium powder when trying to melt it with torch turned black bead with some gold color at the bottom of the bead. 

I was able to dissolve that in nitric and found that there was 600mg gold which was dropped with Palladium when adding DMG. 

I still think there are some PGMs along with gold in that sample from the dried River bed.


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## Geo (Apr 27, 2022)

Any sample that contains gold should have trace amounts (or more) of all other precious metals. It's not unreasonable to find PGM's with native gold.


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## Rick & Carrie (Apr 27, 2022)

kjavanb123 said:


> Thanks Geo. I tried to dissolve that bead in boiling nitric acid for 40 minutes but nothing happened.
> 
> The only bead I have seen with similar look was 7.5g Palladium powder when trying to melt it with torch turned black bead with some gold color at the bottom of the bead.
> 
> ...


If the bead is inquarted with at least three grams of silver, then digested in nitric, it would part the Gold and any pgm's present as a fine powder. Brown powder for gold, and a silvery gray powder for pgms if I remember correct.

Try a partial digest in acid clorox, remove the bead, heat the solution to drive off the free chlorine, then swab test that solution with stannous to see what color it turns.

I also recommend the same swab test using Potassium Iodide to see what reaction color you get.

Add some salt water or hcl to the nitric used to digest the bead and see if white silver chloride forms.

Simple tests to see what you have by confirming known reactions.

It would be entirely possible to smelt enough of that sand concentrate to produce a small silver alloy ingot that could be refined by Electrowinning in a silver cell.

The Gold and any PGM's would fall to the bottom of the tank as a fine powder or slime that could be dissolved into Acid/Clorox or Aqua Regia; even Muriatic Acid (34%HCL) and Sodium Nitrate, then precipitated individually with the refining methods found on this forum.

Then of course melted or calcined to produce a high grade marketable bullion.

We hope this helps.


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## kjavanb123 (Apr 28, 2022)

Rick & Carrie said:


> If the bead is inquarted with at least three grams of silver, then digested in nitric, it would part the Gold and any pgm's present as a fine powder. Brown powder for gold, and a silvery gray powder for pgms if I remember correct.
> 
> Try a partial digest in acid clorox, remove the bead, heat the solution to drive off the free chlorine, then swab test that solution with stannous to see what color it turns.
> 
> ...


Rick

Thanks for the post. I plan to smelt the bead with silver then dissolve in nitric so I can check the solution for Pt. 

I am smelting the coarse size concentrate right now so I can cupel the beads produced from them.


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## Rick & Carrie (Apr 28, 2022)

kjavanb123 said:


> Rick
> 
> Thanks for the post. I plan to smelt the bead with silver then dissolve in nitric so I can check the solution for Pt.
> 
> I am smelting the coarse size concentrate right now so I can cupel the beads produced from them.


Only the silver will go into solution if using nitric. 

The gold and any PGM's will remain as a fine sediment. 

Keep us posted with your results on smelting the course sediments.


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## kjavanb123 (Apr 28, 2022)

Rick & Carrie said:


> Only the silver will go into solution if using nitric.
> 
> The gold and any PGM's will remain as a fine sediment.
> 
> Keep us posted with your results on smelting the course sediments.


Rick

I was on the impression that if the content of Pt in the silver alloy is less than 25 percent, Pt also goes to nitric solution as silver does. 

I believe only Os or Ir Rh would drop as black powder. 

Indeed I would share my smelting and final calculations with the forum. 

If this bead is PGMs gold alloy, then I will be the pioneer in discovering PGMs in the region. 

Thanks 
Kj


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## kjavanb123 (May 15, 2022)

Updates

Smelting the coarse size concentrate from 10kg sample was completed and I am cupeling the lead buttons. 

Here is the picture of lead buttons from smelting.


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## Rick & Carrie (May 15, 2022)

kjavanb123 said:


> Updates
> 
> Smelting the coarse size concentrate from 10kg sample was completed and I am cupeling the lead buttons.
> 
> ...


Thanks for keeping us updated. 

We noticed the iron nails in your lead prills. 

It would be best to scorify those prills down to 1/3 their current weight to get rid of the iron contamination within the prills. 

I do not think that it would cause precious metal loss to the cupel, though it is a contaminant. 

It is faster to scorify down to 1/3 of start weight then cupel anyway. 

I do it on all fire assays that we perform.


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## kurtak (May 15, 2022)

Rick & Carrie said:


> Only the silver will go into solution if using nitric.
> 
> The gold and any PGM's will remain as a fine sediment.
> 
> Keep us posted with your results on smelting the course sediments.


Rick

That not quite true - Pd is also soluble in nitric though less so then silver so there is a very good chance that the nitric can/will dissolve both Ag & Pd (at least some Pd - &/or even all of the Pd)

In other words - concerning the dissolving of the Pd in nitric it depends on conditions as in temp of the nitric when dissolving the silver &/or percent of the Pd in the silver

Temp of the nitric - you can dissolve "pure" Pd with nitric - but - because Pd is "less" reactive (to nitric) then Ag you need to "drive" the reaction on Pd with heat (hot plate) where as silver will dissolve on the heat of its own reaction (no additional heat) --- here we are talking about Ag &/or Pd in a solid form not powders

If finely divided (powders) nitric will dissolve both Ag - or Pd - without additional heat - just that it will take longer to dissolve the Pd as it is less reactive to the nitric then Ag --- here we are talking about dissolving pure powders of Ag - or Pd

So - when dissolving alloys (of Ag/Pd) depending on percentage of Ag to Pd (how finely divided in the Ag the Pd is) you will "*most certainly*" dissolve some of the Pd - if not all of it (in nitric)

And - for what it is worth - nitric will dissolve Pt when alloyed with silver - IF (the BIG IF) the Pt is *VERY* finely divided in the silver --- I don't remember off the top of my head how finely divided (percentage) the Pt in silver has to be for nitric to dissolve Pt alloyed in silver - just that if the Pt is *VERY* finely divided in the silver nitric will dissolve both the silver & the Pt

Edit to add; - Bottom line - when Ag & Pd are alloyed you will *most certainly* dissolve both Ag & Pd with nitric - "*some*" Pd "*may*" go undissolved IF (the BIF IF) the percent of Pd is high enough - AND - Pt will dissolve in nitric IF (the BIG IF again) the Pt if *VERY* finely divided in the silver 

Kurt


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## Rick & Carrie (May 15, 2022)

kurtak said:


> Rick
> 
> That not quite true - Pd is also soluble in nitric though less so then silver so there is a very good chance that the nitric can/will dissolve both Ag & Pd (at least some Pd - &/or even all of the Pd)
> 
> ...



I have also read that Palladium will stain Sulfuric Acid Orange.

If true, I have saw such with black sand samples that I was giving a Sulfuric Acid wash to in order to remove most base metals before further processing.


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## kurtak (May 15, 2022)

Rick & Carrie said:


> I have also read that Palladium will stain Sulfuric Acid Orange.
> 
> If true, I have saw such with black sand samples that I was giving a Sulfuric Acid wash to in order to remove most base metals before further processing.


I don't know how sulfuric reacts with Pd as I don't use sulfuric much in my refining other then using it to drop lead out of solutions

Most of my refining is done on e-waste - not ores

What I do know is that HCl alone will also dissolve Pd - BUT - it (the Pd) has to be *VERY (ultra)* finely divided

The only time I have dissolved Pd with HCl "alone" is when I was processing CATs - the Pd is so VERY finely divided in the wash coat of the CATs that the Pd would dissolve "instantly" when pouring the HCl on the CAT combs & before adding chlorine or nitric to the HCl

Kurt


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## Rick & Carrie (May 15, 2022)

kurtak said:


> I don't know how sulfuric reacts with Pd as I don't use sulfuric much in my refining other then using it to drop lead out of solutions
> 
> Most of my refining is done on e-waste - not ores
> 
> ...


Good info. Thanks.


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## kjavanb123 (May 17, 2022)

Hi


Finally cupeling the lead buttons from smelting coarse size concentrates was finished. 


I produced 7 small silver beads from cupeling them. Here is a close shot of those beads. 



The weight of those silver beads is 0.013 Oz ( 0.369g) which I dissolved in hot nitric acid. 



Here is the bright yellow nitrate solution which didn't produce any color change with my stannous chloride testing solution. 



I plan to cement any value from that solution using zinc powder. 


Here is the gold powder and a doll yellow bead that didn't dissolve in hot nitric acid. 



My plan is to smelt the powder and bead with silver then part with hot nitric acid to find the amount gold from smelting coarse size concentrate 

That black bead resulted from smelting and cupeling fine size concentrate I also would like to smelt with silver then part with nitric acid to see how much gold and or PGM it produces. 

More pictures soon.


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## Geo (May 17, 2022)

Stannous testing the nitric leach will not work unless you kill some of the excess nitric acid. The stannous chloride test acts as an ionic exchange and precipitates the precious metal as solid metal. Just very, very finely divided. If there is excess nitric acid in the sample being tested, especially for Pd, the test results will show negative even if it is not. The excess nitric acid will stop the positive test results. Drop the silver from the sample as a chloride and destroy the excess nitric acid and then test the solution again.


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## kurtak (May 18, 2022)

Geo said:


> Stannous testing the nitric leach will not work unless you kill some of the excess nitric acid. The stannous chloride test acts as an ionic exchange and precipitates the precious metal as solid metal. Just very, very finely divided.* If there is excess nitric acid in the sample being tested, especially for Pd, the test results will show negative even if it is not. The excess nitric acid will stop the positive test results*. Drop the silver from the sample as a chloride and destroy the excess nitric acid and then test the solution again.


Sorry but that simply is not true - if you have PMs in solution you will *always* get a positive result - however - IF (the BIG IF) you have free oxidizer (nitric, chlorine etc.) in solution that positive result may well go away (re-dissolve) --- how fast the positive result goes away depends on two things (1) how much oxidizer is in solution *AND* how you do the test

I posted about this here (more detailed explanation) ------









Interesting ceramic discs on old boards. Silver and/or palladium perhaps?


In this link - post 8 (down from top) Cap number 10 is an epoxy NON-polarized Ta Cap https://goldrefiningforum.com/threads/tantalum-capacitor-scrap-purchasing-international.21530/ Edit to add; - the epoxy - non-polarized (number 10 post 8) Ta Caps are relatively common on more modern CBs Kurt




goldrefiningforum.com





If you have *LOTS* of oxidizer in solution & you do your test in a spot plate the positive result may only last for a second (come & go in a heart beat) do the test with a Q-tip or paper towel & the positive result will last for a minute or longer - longer on paper towel then on a Q-tip

Edit to add; - that's why I always ask members (especially new members) to do there stannous test (when posting pics) on a Q-tip or paper towel instead of a spot plate 

Kurt


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## Geo (May 18, 2022)

kurtak said:


> Sorry but that simply is not true - if you have PMs in solution you will *always* get a positive result - however - IF (the BIG IF) you have free oxidizer (nitric, chlorine etc.) in solution that positive result may well go away (re-dissolve) --- how fast the positive result goes away depends on two things (1) how much oxidizer is in solution *AND* how you do the test
> 
> I posted about this here (more detailed explanation) ------
> 
> ...


Most of the people who come here doesn't have the years of experience that we have. For us, it would be easy to do. A beginner may not know to be watching for a flash of color but instead be watching for a solid color from the test. If they trust their ability and their chemicals, they could toss the sample as being negative. Harold told me when I first started that excess nitric acid will stop the stannous test from displaying a positive. I have been working on that assumption ever since. In my experience, testing a nitric acid leach from MLCC's with stannous chloride produces a soup of flavors. You have silver that turns into a white sludge, the tin itself reacts to the AR formed when you add stannous chloride with nitric acid and produces a frothy texture to the test. Any precious metal positive that does show up tends to be short lived at best in the newly formed AR. As a personal preference, I like to isolate a sample and destroy any free nitric acid first. That way the results are clear with less guessing. If I don't, it is still hard for me to determine a positive and a negative. I can imagine how hard it would be for a beginner.


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## Shark (May 18, 2022)

Kurt and Geo, that is some good information from both of you. I lean toward the qtip for most of my testing these days and that stems from some tests early on that seemed to “change”. I know more about why that happens these days but have never had it explained that clearly.

Edited for spelling


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## kjavanb123 (May 19, 2022)

Hi

The primary result of smelting and cupeling fine size concentrate from 10kg sample was 0.113g gold. 



All the gold recovered from smelting and cupeling coarse size concentrates are being dried for weighing.


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## kurtak (May 19, 2022)

Geo said:


> Most of the people who come here doesn't have the years of experience that we have. For us, it would be easy to do. A beginner may not know to be watching for a flash of color but instead be watching for a solid color from the test.


Geo

*Thank you* for the reply & yes I totally agree

Don't have time today to post more as I spent all my time this morning searching *OLD* threads

This (testing) is worthy if not need for further discussion IMO

Kurt


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## kjavanb123 (May 20, 2022)

Hi

I have finished the calculations for smelting this sample.

Gold from smelting and cupeling fine size concentrate weighs 0.004 oz (0.113g)

Gold from smelting and cupeling coarse size concentrate weighs 0.003 Oz (0.085g)

Therefore total gold powder recovered from 10.798 kg gravel sample collected at a dried stream is 0.007 Oz (0.198g)



So that means 18g of gold per metric ton of this gravel sample.

It seems like a good area as most of the milling was already done by nature and sifting followed by gravity separation can produce coarse and fine concentrates to be smelted.

More projects coming soon as I am prospecting for PGMs.


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