# General steps to process placer gold?



## carcrossguy (Feb 5, 2011)

It's assayed at 91 percent gold, 7 percent silver, and 2 percent waste. I only have 11 oz so the silver is not worth harvesting.

1. how do i get rid of 2 percent waste?
2. why would i want to inquart it?
3. any easy way to recover the small amount of platinum?


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## nickvc (Feb 5, 2011)

If there's any large nuggets don't refine them they fetch more as collectors items than their gold value.
As this is a high grade gold it's straight to AR, it should dissolve easily leaving the silver as a chloride which can be filtered off and left in a plastic container covered with water until you have enough to recover. The filtered gold solution can be precipitated with SMB or the precipitant of your choice and once rinsed as in Harolds method you should have gold of 995+ . I don't think the platinum will precipitate so cement the platinum out on copper sheet and keep for later recovery when the volume warrants the effort, stock pot.
The waste solution should then be treated with iron to remove the copper and then neutralised with lye which will precipitate all other metals and leave a fairly harmless solution to dispose of.


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## carcrossguy (Feb 5, 2011)

nickvc said:


> If there's any large nuggets don't refine them they fetch more as collectors items than their gold value.
> As this is a high grade gold it's straight to AR, it should dissolve easily leaving the silver as a chloride which can be filtered off and left in a plastic container covered with water until you have enough to recover. The filtered gold solution can be precipitated with SMB or the precipitant of your choice and once rinsed as in Harolds method you should have gold of 995+ . I don't think the platinum will precipitate so cement the platinum out on copper sheet and keep for later recovery when the volume warrants the effort, stock pot.
> The waste solution should then be treated with iron to remove the copper and then neutralised with lye which will precipitate all other metals and leave a fairly harmless solution to dispose of.



Appreciate you sharing your knowledge. I'll gradually assemble the knowledge, skills, and equipment so I can do this safely and efficiently.


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## texan (Feb 5, 2011)

Unless you are going to start doing this as a long term venture I would suggest sending the placer gold you have to a professional refiner...there is a thread here that has a discussion of various refiners. It will cost you more than the 3 percent or so haircut to get set up to refine and your newbie losses will probably be more than what the professional refiner will charge. There actually are honest refiners out there. Not to pump a particular firm but ARA in Dallas has a good rep here on the forum.

Texan


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## carcrossguy (Feb 5, 2011)

texan said:


> Unless you are going to start doing this as a long term venture I would suggest sending the placer gold you have to a professional refiner...there is a thread here that has a discussion of various refiners. It will cost you more than the 3 percent or so haircut to get set up to refine and your newbie losses will probably be more than what the professional refiner will charge. There actually are honest refiners out there. Not to pump a particular firm but ARA in Dallas has a good rep here on the forum.
> 
> Texan



I was thinking of making 1 gram bars and selling them 1 gram at a time into eternity. I know precisely how much I have so Im not too worried about dishonest refiners. Nobodies honest, btw; unless someone is watching them.


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## texan (Feb 5, 2011)

Texan


> I was thinking of making 1 gram bars and selling them 1 gram at a time into eternity. I know precisely how much I have so Im not too worried about dishonest refiners. Nobodies honest, btw; unless someone is watching them.



As President Ronald Reagan was fond of saying..."Trust but verify."

Texan


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## goldsilverpro (Feb 6, 2011)

In general, you treat placer gold just like karat gold. If the silver is too high, you will have to inquart.


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## carcrossguy (Feb 6, 2011)

goldsilverpro said:


> In general, you treat placer gold just like karat gold. If the silver is too high, you will have to inquart.




What is too high silver content? Mine is 7%. Clorox method sure did not work.


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## Barren Realms 007 (Feb 6, 2011)

carcrossguy said:


> goldsilverpro said:
> 
> 
> > In general, you treat placer gold just like karat gold. If the silver is too high, you will have to inquart.
> ...



Depending on how much material you have you can run a test batch and if the silver loks the reaction up then you will know the silver content it too high and you can back up and regroup and go a different route.


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## rusty (Feb 6, 2011)

carcrossguy said:


> It's assayed at 91 percent gold, 7 percent silver, and 2 percent waste. I only have 11 oz so the silver is not worth harvesting.
> 
> 1. how do i get rid of 2 percent waste?
> 2. why would i want to inquart it?
> 3. any easy way to recover the small amount of platinum?



Gold and its alloys above 15% gold content must be inquarted with silver, copper or brass in sufficient quantity to bring the purity of the gold down to acceptable levels that the nitric acid will leach them out leaving that beautiful brown powder behind to be collected in the filter paper.

Since you already have 7% silver, I would use more to inquart.

During the iquarting process while the metal is still molten, pour it slowly into a pail of cold water, this makes cornflakes with more surface area exposed to the nitric acid the first stage of refining that gold will go a lot faster.

For a second refining you would go to AR, precipitate with SMB, oxailic acid or SO2

After the cornflakes have been digested in the acid you will be left with brown powder in he bottom of your beaker, collect this in your filter, add some scrap copper to the left over leach and the silver will cement out.

If any platinum group cemented out with the silver, you need to make up a small silver cell. Melt the cemented silver into an anode, insert anode into a cloth bag, with positive DC electricity applied to anode silver migrates to negative cathode as crystals leaving Pt group metals in bag as sludge.

When you have acquired enough pt group sludge refine as per hokes instructions,


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## goldsilverpro (Feb 6, 2011)

Were it me, with the Ag at 7%, I would go directly with aqua regia. I would cover the gold with about 150 ml of Muriatic acid per ounce of gold and then heat it up, pretty hot, but don't boil it. I would then add a small amount of nitric (maybe, 7 ml/ounce of gold). Let it fizz and, when the fizzing slows down, add a little more nitric. Do this until a nitric addition produces no reaction. Stop adding nitric. Let it cool. Either add 3 times more water than you have acid or cool it considerably with ice. Filter the solution. Drop the gold with either SMB or sodium sulfite, photo grade. I prefer the latter.


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## rusty (Feb 6, 2011)

goldsilverpro said:


> Were it me, with the Ag at 7%, I would go directly with aqua regia. I would cover the gold with about 150 ml of Muriatic acid per ounce of gold and then heat it up, pretty hot, but don't boil it. I would then add a small amount of nitric (maybe, 7 ml/ounce of gold). Let it fizz and, when the fizzing slows down, add a little more nitric. Do this until a nitric addition produces no reaction. Stop adding nitric. Let it cool. Either add 3 times more water than you have acid or cool it considerably with ice. Filter the solution. Drop the gold with either SMB or sodium sulfite, photo grade. I prefer the latter.



Thanks Chris, would you cornflakes the gold before proceeding to AR.

Best Regards
Gill


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## nickvc (Feb 7, 2011)

Personally as it's placer gold which I believe is small pieces I'd just go straight for the AR process, no need to melt it, and it keeps potential losses down.


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## goldsilverpro (Feb 7, 2011)

rusty said:


> goldsilverpro said:
> 
> 
> > Were it me, with the Ag at 7%, I would go directly with aqua regia. I would cover the gold with about 150 ml of Muriatic acid per ounce of gold and then heat it up, pretty hot, but don't boil it. I would then add a small amount of nitric (maybe, 7 ml/ounce of gold). Let it fizz and, when the fizzing slows down, add a little more nitric. Do this until a nitric addition produces no reaction. Stop adding nitric. Let it cool. Either add 3 times more water than you have acid or cool it considerably with ice. Filter the solution. Drop the gold with either SMB or sodium sulfite, photo grade. I prefer the latter.
> ...



Not with placer, since it's usually so small to start with. If the nuggets are large enough to require shotting, they should demand a premium, as is. The only problem with direct AR (as opposed to inquartation) is that there may be small amounts of undissolved gold hung up with the silver chloride. This would be treated separately.

If the Ag is much higher than 7%, inquartation would be required.


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## mlgdave (Feb 7, 2011)

As I have stated, DONT refine your placer, I will pay you more than you will get refining it, I buy nuggets and have a solid 10 year reputation. I am also accreditted A+ with the BBB. I buy all placer #14 screen and up.

[email protected]

mlgdave


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## shaftsinkerawc (Feb 7, 2011)

How about minus #14 screen?


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## mlgdave (Feb 7, 2011)

I dont have as large a need for <#14 screen but would consider it on a case by case basis, most times you better off refining depending on quantity

mlgdave


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## Barren Realms 007 (Feb 7, 2011)

mlgdave said:


> I dont have as large a need for <#14 screen but would consider it on a case by case basis, most times you better off refining depending on quantity
> 
> mlgdave



If you keep advertising your site to everyone here in all the threads the mod's are going to hand you your head. Put it in one place and everyone will see it. No need for us to keep reading this.


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## mlgdave (Feb 7, 2011)

Thanks Barren, im done, today was the first day I have seen this site and wanted to reply to some of those questions, i have modified some of my posts to not include my website and am instead asking for private replies. I have also donated to lazersteve website and of course am going to add a link on my site to this site and lazer!

Appreciate your input a lot. I am frikking excited to learn this new hobby/proffesion. I currently pay 5% of SPOT for my refining costs and on any given week thats over 1k..............time for me to be recouping that!!

mlgdave


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## Barren Realms 007 (Feb 7, 2011)

mlgdave said:


> Thanks Barren, im done, today was the first day I have seen this site and wanted to reply to some of those questions, i have modified some of my posts to not include my website and am instead asking for private replies. I have also donated to lazersteve website and of course am going to add a link on my site to this site and lazer!
> 
> Appreciate your input a lot. I am frikking excited to learn this new hobby/proffesion. I currently pay 5% of SPOT for my refining costs and on any given week thats over 1k..............time for me to be recouping that!!
> 
> mlgdave



We don't mind you doing it, but there is a certain area on the forum for you to do it in. Once you get use to navigating the forum you will find this out. We are all here to help you as much as you need help all we ask is that you put a little effort into finding answers. Download a copy of Hoke's handbook if you don't already have it and do some reading in it and it will probably answer most of your questions. If you hit a wall we will be glad to help you out.

Oh and welcome to the forum.


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## mlgdave (Feb 7, 2011)

I have downloaded both Hoke books and the 2 test books as well, printed them out and told the wife that shes got a few nights off...............

mlgdave


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## djui5 (Feb 9, 2011)

nickvc said:


> leaving the silver as a chloride which can be filtered off and left in a plastic container covered with water until you have enough to recover.



Do you have any pictures of this? I've been processing some ore from the Sleeper Mine in Nevada and my AR keeps depositing these large white crystals when left overnight. I thought it was excessive Urea or something? I tested the solution and there is no Gold in it, just these white crystals. Thanks.


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## Harold_V (Feb 9, 2011)

djui5 said:


> nickvc said:
> 
> 
> > leaving the silver as a chloride which can be filtered off and left in a plastic container covered with water until you have enough to recover.
> ...



If your solution is AR, it *isn't *depositing silver crystals. I'd suggest you investigate the idea that it's lead. Silver, in AR, produces silver chloride, which does not grow crystals. 

Why you are processing an ore with AR escapes me totally. Can you give me a clue why?

Harold


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## djui5 (Feb 9, 2011)

Harold,
thanks for the reply. This is super rich Gold ore. A friend showed me how to do all this and so far its working, I think. I'm getting Gold, I'm just not sure if I'm getting all of it. I've been crushing the rock, cleaning it with HC, dissolving the Gold in AR, and precipitating with Sulfide Bisulfite after deactivating the AR with Urea. I'm really just looking to get the Gold out as I'm new to all of this. At some point I'd like to be able to separate the other metals out. 

I just posted a picture in the gallery of a button I got out of a 25gram piece of rock. The button weighs 2.7grams 


edited to change SMB to SB.


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## Harold_V (Feb 10, 2011)

Thanks for your response. 

Not too long after I posted my question, I ran across your other post in a different forum. It helped me understand your approach, and certainly confirmed that you are achieving success, in spite of the less than great approach. You may have one of the rare cases where the use of AR is acceptable for processing an ore, assuming you are eliminating troublesome materials prior to the introduction of AR. I trust that's what you're talking about with the HC cleaning. 

As far as getting "all of it", that's highly unlikely. All you can do is take what comes easily and be satisfied, unless you're leaving behind a high percentage. That's common practice, where there is a diminishing return curve. You can expend only so much effort before it costs more than that which is recovered is worth. 

It's *very rare *for anyone to have a high grade gold ore at their disposal. Many of the mines in production are handling a ton of ore to recover as little as .10 troy ounce. 

Do keep us posted on your progress.

Harold


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## djui5 (Feb 10, 2011)

Harold_V said:


> Thanks for your response.
> 
> Not too long after I posted my question, I ran across your other post in a different forum. It helped me understand your approach, and certainly confirmed that you are achieving success, in spite of the less than great approach.
> Harold



Harold,
If you are familiar with a more efficient process I would love to hear about it. Like I said I'm a newb to all this stuff  I did send a sample of the rock to ARA for them to process, and see how much Gold they get out of the rock. They use AR also, but precipitate with SO2 instead of SB like I do.

I've done this process to two types of ores now, this ore being the 2nd, and it's worked both times. I have some other types of ore I plan to process soon that are not so high in the Gold content, and I'm sure have other metals in them, IE Tellurides.

BTW I'm aware how rare these rocks are and am very lucky to have them for processing/whatever. It really is nice to have legit ore like this for getting Gold out of. :mrgreen:


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## Platdigger (Feb 10, 2011)

djui5, you said "Sulfide Bicarbonite" 

Did you perhaps mean sodium bisulfite?
Welcome to the forum.


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## djui5 (Feb 10, 2011)

Platdigger said:


> djui5, you said "Sulfide Bicarbonite"
> 
> Did you perhaps mean sodium bisulfite?
> Welcome to the forum.



Yea, whoops! :lol: I can't remember these names unless I look at the bottle. :lol:


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## Harold_V (Feb 11, 2011)

djui5 said:


> I've done this process to two types of ores now, this ore being the 2nd, and it's worked both times.


A great deal depends on the volume of value contained within the ore, as well as the consumption of acid as compared to the value of the recovered metals. It's not that it doesn't work, it's that it generally isn't cost effective, plus it can be troublesome. Try recovering gold from a heavy concentration of pyrite, for example. 

At any rate, you're obviously doing something right. 8) 

Harold


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## eeTHr (Feb 11, 2011)

Juice---



djui5 said:


> my AR keeps depositing these large white crystals when left overnight.




What are you using for nitric? Store bought, home made, or just sprinkling powdered nitrate into the HCl?


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## djui5 (Feb 11, 2011)

eeTHr said:


> Juice---
> 
> 
> 
> ...




It's laboratory grade 70% Nitric bought at a prospecting store.


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## eeTHr (Feb 12, 2011)

Sounds like it's dissolving something from the ore, saturating it at room temperature, then at night it cools and forms crystals of it.


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## djui5 (Feb 13, 2011)

That's possible. I'm pretty sure it's excessive Urea. I'll find out soon enough as I'm going to process some more of this stuff next week. I'll be using a lot less Urea this time. I've found dissolving it into heated water first and using that seems to require far less than just dumping pellets into AR.


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## qst42know (Mar 6, 2011)

Have you had this ore assayed for other pm's you may be missing?

I wonder if cementing with copper might be more useful than urea?


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## djui5 (Mar 8, 2011)

No I haven't had it assayed. Copper is a thought.


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## eeTHr (Mar 8, 2011)

Juice---

Are you saving your solutions after you drop out the Au?

Hang a copper bar, or AWG #00 uninsulated copper ground wire (from any hardware store) into that solution for a day, that will precipitate any remaining PMs. Decant the solution and save any PMs powder on the bottom, then put some nails in the remaining solution to precipitate the copper and any other base metals. Pure iron is better to use, if you have any around, because steel has a little bit of additives that will come off as it dissolves, and be in with your copper and stuff.

That will give you some idea of what you've got in there.

If you use the #00 wire, bend the end into a spiral, for more surface area in the solutiion. Make a bend in the other end to hang it over the lip of the container. Bend the spiral at 90 degrees to the straight part of the wire, so it is horizontal in the solution.

Don't use copper tubing, because some PMs will stick to the inside. Unless you cut it in half down the length of it. That way you can scrape off any stuck PMs.


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## djui5 (Mar 9, 2011)

I'll have to try that on the next batch. Some of these ores are becoming a pita to deal with. A batch I crushed up last night is some red rock kinda like Jasper, and it has Azurite in it, with what I thought was Gold, but could be a tin/copper alloy that looked a lot like Gold. Plus my stannous mix is useless. I mixed up the whole 1/4lb with water not knowing it degrades over time. After testing it tonight with some pure AU in AR it seems it isn't working anymore :lol: :lol: 

Ahh the fun in learning new things and trail/error. I love it. This is the spice of life :mrgreen:


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## Richard36 (Mar 9, 2011)

djui5 said:


> . A batch I crushed up last night is some red rock kinda like Jasper, and it has Azurite in it, with what I thought was Gold, but could be a tin/copper alloy that looked a lot like Gold.



I'd like to see a photo of that red jasper-like ore.
I have found similar ores, and they do contain high values.

I'm beginning to think that such ores are created by some sort of biogenic precipitation process from algae and/or bacteria within late period hydrothermal solutions resulting within the mountain ranges of the world that were created by the process of anatexis (subduction) and the resultant mountain building processes it creates along plate margins.

Wheh! that was a mouth full, lol! :lol: 

Anyway, yeah, if it's glassy such as Jasper, then it's a chemical sedimentary rock resulting from groundwater that was saturated with silica, and the silica dropped out of solution as it reached super saturation and/or cooled/evaporated. 

The rock is red from iron enrichment, so, iron eating bacteria were present to strip the iron from the surrounding rock and soil, thereby enriching the water with iron, and providing a nutrient rich solution in which the bacteria could live. 

some such strains of bacteria release cyanide or cyanide like compounds into the water thereby leaching any precious metals from the soil and rock in contact with it. In areas where this solution is concentrated and evaporated, secondary enriched deposits form. 

In your case, silica was precipitated along with iron and gold, as well as silver, if it's there. 

I suppose Platinum group metals could occur in secondary enriched deposits in this way, 
the chemistry is present, but have never heard of such a deposit being found.

Sincerely, Rick. "The Rock Man".


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## djui5 (Mar 9, 2011)

Rick, you're description would make sense and explain why the rock looks like it does. I was perplexed when I first looked at it:


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## eeTHr (Mar 9, 2011)

Juice---

The only two _elemental_ metals that have color (not silvery or grey) are copper and gold.

Anything else with a gold color would have to be either an alloy containing copper, or a mixture of other metals together with non-metalic minerals which would behave differently than metalic alloys.

Use the tip of a knife to gouge some color out, then put it on white paper and smear it in a line with the knife tip. Usually you can tell if it's totally metalic or not. You can check it with a magnifying glass. If the smear remains shiny, it's metalic; then if it's got color it is, at the least, a copper alloy. Then you can test in on a stone with testing acids to see if it's at least 10K or more. Or scrape a good amount of it off, and put it in a little nitric, and see if any PMs remain undissolved. And so forth (add HCl, dissolve it, then precipitate it; if you don't have stannous handy at the time). Don't use more nitric than is absolutely necessary, as it will prevent your stannous from showing color, as well as prevent precipitation. (If you had a lot of nitric in your solution, that may be all that's wrong with your stannous testing now.)


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## djui5 (Mar 9, 2011)

Whoa! I didn't know too much Nitric would prevent stannous color and prevent precipitation. Holy crap.


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## Harold_V (Mar 9, 2011)

djui5 said:


> Whoa! I didn't know too much Nitric would prevent stannous color and prevent precipitation. Holy crap.


You _*should*_ have known. 

Read Hoke.

Harold


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## djui5 (Mar 9, 2011)

I haven't had time to read it. I'll do it this week


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## Richard36 (Mar 10, 2011)

djui5 said:


> Rick, you're description would make sense and explain why the rock looks like it does. I was perplexed when I first looked at it:



If that brassy spot in the sample shown isn't a sulfide, and is actually native element, then you have some really good ore with metal in that concentration, let alone all the micron gold that would be dispersed throughout the ore body.

I hope that the grade is that high all through your deposit.

Sincerely, Rick. "The Rock Man".


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