# Gold Powder and Borax cannot dissolve on the water



## j2000 (Feb 9, 2014)

Greetings…
Hi, i’m Joel, from Indonesia…

Actually i dont have much experience in gold processing…
But my customer give me sample for test by me, the gold powder but not pure…
My customer want me to pure it to be gold powder.

*Step i have done is:*
1:Melting it on oven around 1150 degree celcius (2102 fahrenheit) and mix with borax.
2:After done to burn it, i grinding it to be powder again.
3: After grinding, i wash/clean it with hot water and mix with citric acid OR Acetic Acid for remove the borax (many times).

*The problem is:*
Borax is dissolve in water, but not all of them…
If i check on microscope, much gold still stick with borax.
My customer said: this is not good, almost clean 99 percent borax from 1st melting.

I just confuse:
My customer request to me remove borax after melting, and wash it from borax and after clean from borax that gold will “melting with borax again”.

*Questions:*
Can i melt with borax again where it still little borax from first washing?
Or I must use special borax (borax chapman) for better result (i have order it)?
Anybody know, what is best solution (chemical) for dissolve borax in the water?

*I make small video after washing the borax from microscope:*
http://youtu.be/LbCNvS6ymF8

Thanks and sorry for much question.

Joel


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## sharkhook (Feb 9, 2014)

You can do a search for "removing borax", comes up with good results. Here is just one.

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=15248


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## Harold_V (Feb 9, 2014)

Joel,
You would be best served to collect all of the solids and remelt, using some fresh borax, a little soda ash and some fluorspar, to thin the flux. It takes very little fluorspar to accomplish the task, and I advise that you use only a small amount, as it is very hard on melting dishes and crucibles. You may even have to use a collector (more gold, or even some silver), as the finely divided bits of gold will be difficult to capture otherwise. 

If someone presents you with gold powder, and you're sure it's gold, it's best that you do NOT melt the powder if you hope to further purify. It's much easier to simply dissolve the powder, filter, and precipitate, leaving behind most of the contaminants. You can learn about that by reading Hoke's book, which I strongly advise. 

If you choose to re-melt, as I advised, you'd be best served by doing so in a furnace, where you can hold the temperature for a period of time, allowing the values to collect. You may enjoy success using a torch, but it's not easy keeping the temperature high enough for a prolonged period of time, although it is possible. 

To remove borax from gold, it can be boiled in dilute sulfuric acid. All of the borax will dissolve if you have enough water present and give it a long boil. 

Be advised that you are far better served to melt gold without using borax. A thin coating of the melting dish is more than adequate. Otherwise you experience the very thing you're fighting now---gold tied up in the slag. 

Harold


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## butcher (Feb 9, 2014)

Welcome to the forum Joel,
Listen to Harold.

Hokes book is a must read for anyone wishing to learn more of how to refine precious metals, or learn more about gold.

I think if you give some more details about this material you have and its source, it may also help you get an answer to help with your problem, is this an ore? Jewelers waste or what is its source? I agree with Harold most of the time melting powders is not the best approach, many times it is easier to separate gold from the other material before melting, but again this can also depend on the materials or its source.

Most every process in recovery or refining many times depends on the material where many times the material determines how it should be treated for recovery or refining.

Depending on the material, and what the other stuff is in the melt (ore gangue), a collector metal may need to be added, and proper flux may be needed to get the metals to combine, and then the button of metal parted for its gold content.
Or it may be better to separate the gold from the other material by some other means before melting, if this is Ore it can sometimes be complicated to find the best approach to deal with the problem of getting the gold out of it.

You problem with this gold powder, Has lead you to the best place for you to learn, and improve your skills, the forum is a great resource for learning, studying here on the forum will be more valuable to you in your future than the gold in that borax, it will take time to learn it, but nothing worth having comes easy, and learning this is not easy but it can be fun and very valuable.

Links to a free download of Hokes book can be found in the book section or links in many members signature lines.


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## FrugalRefiner (Feb 9, 2014)

butcher said:


> Links to a free download of Hokes book can be found in the book section or links in many members signature lines.


Like mine. 8) 

Dave


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## j2000 (Feb 10, 2014)

sharkhook said:


> You can do a search for "removing borax", comes up with good results. Here is just one.
> 
> http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=15248



Thank very much shark, i will learn on that link....

But for Acid from wet battery, my customer tells me (because he have to try before) that the battery acid is not an effective, acid binds to the borax but also gold powder. 

That's why I tried to ask if there is a chemical composition that can dissolve Borax to water, Like the sugar is dissolved into warm water.

Regards

Joel


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## j2000 (Feb 10, 2014)

Harold_V said:


> Joel,
> You would be best served to collect all of the solids and remelt, using some fresh borax, a little soda ash and some fluorspar, to thin the flux. It takes very little fluorspar to accomplish the task, and I advise that you use only a small amount, as it is very hard on melting dishes and crucibles. You may even have to use a collector (more gold, or even some silver), as the finely divided bits of gold will be difficult to capture otherwise.
> 
> If someone presents you with gold powder, and you're sure it's gold, it's best that you do NOT melt the powder if you hope to further purify. It's much easier to simply dissolve the powder, filter, and precipitate, leaving behind most of the contaminants. You can learn about that by reading Hoke's book, which I strongly advise.
> ...



Woww many thanks Harold, for this time i will use melting way...
I use electric furnace with graphite crucible, i hold the temp 1150C/2102F for around 5 to 10min, sometime i try to 1300C/2372F but only few second and stop.

I need to ask or your suggestion, as i know melting gold arounf 1064C, how much highest degree (safe) for this aplication and how long to hold on that temperature?

About "dilute sulfuric acid", how many percent concentrate you suggest?

Iam sorry for my question because i really don't have experience for chemical 

Regards

Joel


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## Geo (Feb 10, 2014)

First let me say that, you can not refine gold by melting with flux. It does not work that way. The melting point of gold is 1064.18 °C. You should bring your melt beyond this temperature for as long as it takes for all the tiny prills to form one solid mass. The boiling point of gold is 2856 °C. Do not exceed this temperature even if you can. Gold will volatilize at this temperature and beyond and turn into a vapor. Within those two ranges, your gold will be safe unless you add a chemical that oxidizes gold at high temperature. 

I believe you missed the point that Harold tried to make in his first post, to make the gold pure, you must dissolve the gold with acids and then precipitate the gold back in a more pure state. By milling or crushing the borax glass and thereby liberating the tiny pieces of gold, you will allow the acids to reach the gold trapped inside.

Battery electrolyte (sulfuric acid 10%) should work to dissolve the hardened borax glass.

Take a look here. http://en.wikipedia.org/wiki/Gold

Dont forget to download and read C.M. Hoke's book "Refining precious metal waste".


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## sharkhook (Feb 10, 2014)

One of the more knowledgeable members can correct me if I am wrong, but some higher strength acids can passivate some materials, while the dilute form can actually attack the same given material. As I understand it, that is the reason for diluting the sulfuric acid to around the 10% range for it to work on the borax.


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## Palladium (Feb 10, 2014)

Boil in nitric. As fine as the prills should be it should remove the flux and some of the base metals to. But the gold that comes from it will be real finely divided and hard to catch unless you use a good filter paper and filter twice or three times through the same filter so that it packs the filter.


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## j2000 (Feb 19, 2014)

Palladium said:


> Boil in nitric. As fine as the prills should be it should remove the flux and some of the base metals to. But the gold that comes from it will be real finely divided and hard to catch unless you use a good filter paper and filter twice or three times through the same filter so that it packs the filter.




U r correctly, i have to use Citric Acid, all borax dissolve in wate with acid, but the gold powder now on acid, even in 24 hour i still can see very tiny gold powder float on the acid.

I also have to neutralized the acid to normal (ph7) with X19 (my friend said the name is X19), but the borax is back in the water.


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## au-artifax (Feb 19, 2014)

I hope nobody takes offense by this question, but it is a sincere attempt to help; are there any known downloadable versions of Hoke's book done in other languages? I have read so many threads where "Hoke " was referenced, where it seemed like the OP was struggling with the English language to begin with.
Again, no offense meant, but my daughter is a corporate translator for this very reason, to facilitate and foster concise and accurate communication. This is a concern also because there is no place for error in any scientific discussion or writing.

Does anybody know of any translated versions of Hoke's book?


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## dannlee (Feb 19, 2014)

Yeah, it's an extra layer of difficulty but people with 'English as a second language' who have reached goldrefiningforum.com may already know to use http://translate.google.com/ to help with forum threads... and the miracle of cut-and-pasting blocks of text from Hoke's Book to translate for a better understanding is a huge boost that was unknown just a few years ago (even if it is translate to a third language they're more familiar with). 

Whether by accident or design the language of science is English, 98% of all scientific articles are published in English. Just maybe not with 1930's and 1940's sentence structure


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## bmgold2 (Feb 19, 2014)

dannlee said:


> Yeah, it's an extra layer of difficulty but people with 'English as a second language' who have reached goldrefiningforum.com may already know to use http://translate.google.com/ to help with forum threads... and the miracle of cut-and-pasting blocks of text from Hoke's Book to translate for a better understanding is a huge boost that was unknown just a few years ago (even if it is translate to a third language they're more familiar with).
> 
> Whether by accident or design the language of science is English, 98% of all scientific articles are published in English. Just maybe not with 1930's and 1940's sentence structure



That same link should translate the whole pdf book for you. Below the text box is a blue link named translate a document.

I tried it with the hoke book but since I only read English it didn't do me any good. What language do you need? If you can't get the book to translate I'll try to do it and post the file here if I can.

I just tried it again to translate the screen readable version into Indonesian. It looks like it did it but the pictures did not get included with the translation. I copied and pasted it into a word processor and saved it as a PDF file. If anyone like j2000 (Joel from Indonesia) wants this file, send me a private message here with your E-mail address and I'll send it to you if you catch me pretty quick. If not, I'll just delete it since I can't read it myself. That link should get it translated for you yourself into about any language you want. I'd save the English version to your computer and then upload it to be translated and then you can go back to that version for the pictures.


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## j2000 (Feb 25, 2014)

bmgold2 said:


> dannlee said:
> 
> 
> > Yeah, it's an extra layer of difficulty but people with 'English as a second language' who have reached goldrefiningforum.com may already know to use http://translate.google.com/ to help with forum threads... and the miracle of cut-and-pasting blocks of text from Hoke's Book to translate for a better understanding is a huge boost that was unknown just a few years ago (even if it is translate to a third language they're more familiar with).
> ...



Many thanks Bmgold2, i will send PM to you...

Kind regards

Joel


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## j2000 (Feb 25, 2014)

Palladium said:


> Boil in nitric. As fine as the prills should be it should remove the flux and some of the base metals to. But the gold that comes from it will be real finely divided and hard to catch unless you use a good filter paper and filter twice or three times through the same filter so that it packs the filter.



Thanks Palladium,...
I still order filter with mesh 400 to 1000, i still don't exactly size of the powder of gold after melted and pour to the water...
and i think your suggestion is best result for now...step> : melt it, grinding, wash, filter it, remove iron and remelted, .... 

Regards

Joel


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