Gold Recovery
- Thread starter Yash
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niteliteone
Well-known member
Yash said:
Yash,
You have posted 2 different alloys earlier.
Which one is dissolved into the 50% nitric acid in the picture?
Or,
Has all the metal dissolved?
Leaving only powder in the bottom of the glass.
If complete then carefully decant liquid. (remove the liquid through a filter into another container)
This liquid will contain almost all of the copper, silver, iron and zink/lead. If you add more copper to this liquid you can recover your silver.
With the powder still in the first container rinse with water to remove any colored liquid but not any solids or powder. These are your gold.
After rinsing the gold powder add a small amount of HCl to cover the powder 100ml (3to4mm) then with a dropper add 2 to 3ml nitric acid. Add a little heat (60 to 70C)
The solution should start to dissolve the powders in the beaker. Should turn yellow color.
When you have done this tell me what has happened and show a picture and I will help more after I see the picture
Completely understand what I told you before you do it. If you don’t understand or have a question ask it before you follow these instructions.
I will wait for your answer.
Tom C.
goldenchild
Well-known member
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- Aug 14, 2009
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- 1,810
niteliteone said:
Not trying to start any trouble here but... why give the process in the first place? It's clear that Yash is looking for the quick and easy. He is without a doubt going to try this.
niteliteone
Well-known member
goldenchild said:
Well he did finally do as me and a couple of others told him would work in the beginning.
So I feel if he is truely wanting to learn I would offer a partial set of instructions and see if he would follow them. That is why I asked for the picture of the results.
I'm still on the fence as to his intentions here. (check my first post to him on page 1)
But if it is just a language barrier I would like to find a way to overcome it. That was why the instructions were clearly written so to translate easy if needed.
If this doesn't work I will then know which side of the fence I belong on.
Tom C.
P.S. No trouble felt.
- Joined
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- 8,360
You would be far better served to provide information that will help those who try to give you decent guidance, and stop being so damned defiant.Yash said:
I'm about to the end of my patience here. You, sir, are rude to those who try to help you. If you can't respond kindly, you're not going to last much longer. Comments such as this:
are not acceptable on this forum. You are not a moderator, you are a reader. Behave accordingly, and leave the discipline to those of us who have been assigned. If you have an issue with a fellow member, file a complaint with one or more of the moderators. Do not post antagonistic comments.
Do you understand me?
Harold
My replies to this thread have I hope all been pointing Yash in the direction of doing some of the necessary reading so that he knows himself what to do with the materials he's asking about and save him time and expense trying to refine worthless material. If the metal he dissolved in nitric has nothing left undissolved there was no gold there in the first place, that's where testing comes into the picture to know what your actually working with. We could spend the next month going back and forth with various materials and suggesting all the methods he could use but will he ever learn anything.
The purpose of the forum as I see it is to educate those interested in recovering and or refining precious metals to an acceptable level and safely, to do this studying the recommended books and spending time reading threads on the forum that relate to the process or material to be worked on gives a good insight into what to expect and why. Those that won't will never make a good refiner and will more than likely fail at every attempt or will lose the values and more posts and threads will appear asking the same old time worn questions wheres my gold, made a big mess what do I do next?
My advice here mains the same as in my first post.
Read.
The purpose of the forum as I see it is to educate those interested in recovering and or refining precious metals to an acceptable level and safely, to do this studying the recommended books and spending time reading threads on the forum that relate to the process or material to be worked on gives a good insight into what to expect and why. Those that won't will never make a good refiner and will more than likely fail at every attempt or will lose the values and more posts and threads will appear asking the same old time worn questions wheres my gold, made a big mess what do I do next?
My advice here mains the same as in my first post.
Read.
patnor1011
Well-known member
Yash said:
First and foremost say again, what do you have?
Yash.
"(solvent cald sodium auri cyanide)"
I understand the auri cyanide (gold cyanide), but do not understand the word "cald", could you explain its meaning? or could it be translated wrong?
"(solvent cald sodium auri cyanide)"
I understand the auri cyanide (gold cyanide), but do not understand the word "cald", could you explain its meaning? or could it be translated wrong?
niteliteone
Well-known member
Maybe a bad translation of the word "called"
Just a thought
Tom C.
Just a thought
Tom C.
joem
Well-known member
Hi all
This is the question pm'd to me by yash
" have solvent called sodium auri
cyanide so how to extract au from that
solvent , plz reply asap"
Does anyone know the answer? I don't.
This is the question pm'd to me by yash
" have solvent called sodium auri
cyanide so how to extract au from that
solvent , plz reply asap"
Does anyone know the answer? I don't.
Yash said:
I normally don't answer posts that demand information ASAP but I'll make an exception. It's like saying, "I woke up this morning and decided I wanted to be a gold refiner. Drop everything and tell me everything I need to know - RIGHT NOW!" Using the word "please" doesn't count much in that case. Drop the ASAP if you want answers. You'll get them when you get them and not sooner. We're all busy people.
I assume you're saying that you have a solution with sodium gold cyanide dissolved in it and you want to recover the gold. Correct me if I'm wrong. The following will work with potassium or sodium gold cyanide plating solutions. However, if you've made a mistake and the solution is actually sodium gold sulfite, a common compound used in some gold plating baths, it won't work. I would strongly suggest trying a small sample before working the entire lot, to make sure you have the process down. I might note that, if the solution is a commercial gold stripper of a certain type, such as Technistrip Au or certain ACR strippers, the zinc process below will not work. Neither will electrolysis, to any great extent. No matter what you have, I'm not a big fan of electrolysis for this purpose, since you'll likely never get all the gold out. When the gold concentration starts to get low, you start splitting water at the cathode. This progressively lowers the gold deposition efficiency and, at some point, no gold is depositing.
Assuming it is really sodium gold cyanide:
(1) Check the pH. If it's less than 12, raise it to 12 with sodium hydroxide. This is very important to prevent the evolution of the extremely toxic hydrogen cyanide gas during the process. It shouldn't take much sodium hydroxide. Try not to use an excess. After adjusting the pH to 12, add about 5 g/l of sodium or potassium cyanide if you have it handy. The cyanide addition usually isn't necessary but, in some cases, it makes the gold precipitation go more smoothly. If there are any salts formed in the original solution, they can contain gold. Heat the solution to about 70C, with stirring, to hopefully dissolve these salts. Allow to cool.
(2) With stirring, add zinc powder slowly, in increments. I prefer 325 mesh "zinc dust". If possible, don't use zinc powder any finer than 325 mesh and don't use any that contains cab-o-sil, a silica anti-clumping agent. If the zinc dust has "clumped", break it up before using. I use a small squeeze-type flour sifter for this. In most cases, it will take about 1 gram of zinc per gram of gold. Try to find a stirrer that lifts the solution. The last time I did this (a couple of months ago - in a 10 gallon container), I used an actual small cheap rubber toilet plunger with a wooden handle. A prop-type power stirrer is the best. When you first add a little zinc, you should notice that, as you bring the precipitated powder to the surface with the stirrer, it will usually be a brown color (gold). As you add more zinc (a gray color), the color of the powder raised by the stirrer will start to turn gray. When it first becomes fully gray, stop adding zinc.
(3) Hang a zinc bar in the solution and allow the precipitate to settle overnight. The zinc bar helps prevent any gold from re-dissolving.
(4) Separate most of the liquid from the settled solids by siphoning and/or dipping out the solution carefully.
(5) Filter the solids and rinse several times with hot water. The rinsing is very important in order to remove any traces of cyanide.
(6) Transfer the filter paper and the solids to a plastic bucket. Cover the solids with distilled water, Stir with a rod a little to break everything up.
(7) UNDER A FUME HOOD, add a small amount of nitric acid. You should see an immediate reaction and some red fumes. When the reaction dies down, stir a bit and add a little more nitric. Repeat until a small addition of nitric produces no reaction. Keep all the nitric solutions and rinses and combine. Put some lengths of copper tubing or heavy solid copper wire in the nitric solution for silver recovery.
(8) Allow to cool. Filter, rinse well, and dissolve the gold residue in aqua regia. The aqua regia process has been covered over and over on the forum. You'll have to search that out yourself.
NOTE#1: On the initial problem on processing the alloy (10Au, 10Ag, 70Cu, 5Fe, 5Zn or Pb). As 4metals and others have said, everything on this list, except the gold, will dissolve in 50/50 nitric acid. The only possible problem I see is that, with the gold at 10%, some of the remaining gold might be colloidal. This can cause settling and/or filtering difficulties. With all that copper, zinc, and silver in it, the reaction will probably generate enough heat to dissolve most of it. At the end, however, I would transfer the undissolved solids (gold, mainly) to a beaker, add a little fresh 50/50 nitric, and heat it to dissolve that last bit. Filter and rinse the solids and put them through the aqua regia process to purify the gold.
If you did dissolve the base metals and silver completely in nitric and, if no brownish powder (gold) remained after doing so, that means that there was no gold in there to start with. I am assuming no chlorides were present.
Note#2: I wasted about an hour this morning reading and studying this thread. Unless you guys know something I don't know about Yash, it seems to me that he has been treated shabbily. Lots of innuendo without any substance, in my opinion. He did get hot and said some things he shouldn't have said when he was badgered but I would probably have done the same. Why don't we all chill out, give him the benefit of the doubt, start over, and try to answer his questions? Yash, you said a few things you should apologize for.
Note#3: For some reason, I have suddenly been inundated, by PM and email, with about 10 requests from members on getting gold out of a cyanide solution. I don't have the time to answer all these and am hoping this post will take care of most of it, or at least get the generalities out of the way. If not, let me know. You know who you are.
Chris
