HOW TO CAST 1KG GOLD BAR

[hrushi]

I REFINE GOLD BY inquartation AS 100% GOLD IS RECOVERED EVERY TIME NO GOLD IS WASTED(TEMPORARILY) AT END OF EVERY BATCH I GET ALL GOLD.
I USE SS316 VESSEL AS REACTOR. I USE SS REACTOR AS IT IS BETTER THAN GLASS AS IT WONT CRACK.
OFTEN I DONT GET COLOR OF 9950 1KG GOLD BAR. MANY TIMES THERE IS RED COLOR SKIN OR LAYER ON THE METAL. HOW TO REMOVE IT.
SECONDLY HOW IS 1KG GOLD BAR IS CASTED. OF WHAT MATERIAL DIE IS MADE OF??
I THINK DIE IS MADE OF SOME CARBON MATERIAL.
REGARDS
HRUSHI

 

[Geo]

please dont post using all CAPS as it is considered shouting and therefore considered rude. molten gold should never come into contact with other metal (even stainless steel). the best material for casting gold ingots is carbon graphite molds.

 

[hrushi]

please dont post using all CAPS as it is considered shouting and therefore considered rude. molten gold should never come into contact with other metal (even stainless steel). the best material for casting gold ingots is carbon graphite molds.

extremly sorry for all caps
and how do i get good color without doing AR process :?:

 

[publius]

Snip... and how do i get good color without doing AR process :?:

Do a forum search for Acid/Clorox procedure. Also download and read CM Hole's book. You will find links to it in many of the forum members signatures.

 

[kdaddy]

It sounds like you are inquarting, dissolving in nitric, then melting the undissolved material. If this is what you are doing your gold still has impurities, red is most likely copper. There are no shortcuts if you want good purity, AR is your friend.

 

[Claudie]

When dealing with an amount as small as 1 gram, maybe the best way would be to roll the Gold out flat, then use a proper size punch to knock out a planchet. Just a thought. :|

 

[philddreamer]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=9982&p=96025&hilit=melting+gold#p96025

I hope this helps some!

Phil

 

[hrushi]

It sounds like you are inquarting, dissolving in nitric, then melting the undissolved material. If this is what you are doing your gold still has impurities, red is most likely copper. There are no shortcuts if you want good purity, AR is your friend.

I have checked purity on XRF and spectrophotometer it ranges from 99.74% to 99.96%.
thing that you have boil it minimum 2 times in nitric acid after 1 reaction is complete.
I am sure you will achive purity.
if you do reaction in glass beaker you would get very nice color of gold as well
there are two disadvantage of this process
1. lot of Ag is required and again we have to recover Ag.
2. if reaction is done in SS vessel gold gets some kind of red color on top of gold and id ammonium chloride that red color goes as well to some extent but you dont get 1kg 99.50 gold bar color.

thanks
hrushi

 

[Geo]

my guess would be iron from the SS. stainless steel has a resistance to attack from nitric but when you heat the nitric it will attack the stainless to some degree. high grade stainless steel is passivated in nitric by a layer of oxidized (nickle?) preventing attack further at lower temperatures. since nickle is greenish-blue while iron is red, i would say its iron. you cant just clean the outside of the gold and it will be gone as the contamination will be throughout the entire melt.

 

[nickvc]

You could try washing your gold powder through hot hydrochloric so long as you rinse it well with water only a little of the value could dissolve and it could be tested using stannous, this might remove some of the contaminants but obviously you would have to use something other than stainless preferably glass.

 

[qst42know]

How many times have you used the same silver to inquart?

It is possible it has accumulated enough contaminants to be less than effective.

Inquarting as the sole means of refining seems a common short cut in India. Is there a reason you don't finish the job of refining with aqua regia?

 

[kdaddy]

I dosen't matter what the XRF results are, if you have oxides on your melt you have impurities. Have an assay done and you will see how accurate the XRF is. Why would anyone go through all the trouble to inquart just to half ass the job at the end?
P.S. Get rid of the SS and get some glass.

 

[HAuCl4]

It sounds like you are inquarting, dissolving in nitric, then melting the undissolved material. If this is what you are doing your gold still has impurities, red is most likely copper. There are no shortcuts if you want good purity, AR is your friend.

I have checked purity on XRF and spectrophotometer it ranges from 99.74% to 99.96%.
thing that you have boil it minimum 2 times in nitric acid after 1 reaction is complete.
I am sure you will achive purity.
if you do reaction in glass beaker you would get very nice color of gold as well
there are two disadvantage of this process
1. lot of Ag is required and again we have to recover Ag.
2. if reaction is done in SS vessel gold gets some kind of red color on top of gold and id ammonium chloride that red color goes as well to some extent but you dont get 1kg 99.50 gold bar color.

thanks
hrushi

Courtesy of 4metals: Flux to get approx. ~9995 gold after silver inquarting + nitric.

This is the formulation for the flux to scavenge silver and base metals.

Gold Melting Flux
This is for gold from the nitric parting process

2 pounds Anhydrous borax glass (no waters)
1 pound Soda Ash
1 pound Diatomaceous earth (silica)
1 pound Manganese Dioxide
¼ pound Flurospar (calcium fluoride)
¼ pound Calcium oxide (CaO, Lime, Type S, Unslaked)

Premix all of the ingredients and store it in a closed container. It is anhydrous and will pick up moisture from the air which will make it spit.

Add equal volume of gold sponge to flux and premix before melting.

**********************************************
How to make and stamp a 1 Kilo gold bar. Courtesy of Chloroauric Acid :

1-Weight exactly 1001 grams of pure gold (~9995 from above procedure) in pellet / shot form.
2-Melt it WITHOUT borax or any other flux in a silicon carbide or graphite crucible (that is used only for pure gold), reach a good 1,200 C.
3-Pour it in a preheated graphite mold (that is used only for pure gold). Maintain a propane torch flame on top till it solidifies.
4-Mark it with an hydraulic press (made with an hydraulic car jack) and a steel stamp with your seal, and whatever markings you want.
5-Weight the bar in an accurate balance, and file off less than~1 gram from it, till the weight is 1000.5 grams +/-. :lol:
**********************************************
Your process is fine. Glass with nitric parting is for amateurs.

 

[samuel-a]

Courtesy of 4metals: Flux to get approx. ~9995 gold after silver inquarting + nitric.

This is the formulation for the flux to scavenge silver and base metals.

Gold Melting Flux
This is for gold from the nitric parting process

2 pounds Anhydrous borax glass (no waters)
1 pound Soda Ash
1 pound Diatomaceous earth (silica)
1 pound Manganese Dioxide
¼ pound Flurospar (calcium fluoride)
¼ pound Calcium oxide (CaO, Lime, Type S, Unslaked)

Premix all of the ingredients and store it in a closed container. It is anhydrous and will pick up moisture from the air which will make it spit.

Add equal volume of gold sponge to flux and premix before melting.

**********************************************
How to make and stamp a 1 Kilo gold bar. Courtesy of Chloroauric Acid :

1-Weight exactly 1001 grams of pure gold (~9995 from above procedure) in pellet / shot form.
2-Melt it WITHOUT borax or any other flux in a silicon carbide or graphite crucible (that is used only for pure gold), reach a good 1,200 C.
3-Pour it in a preheated graphite mold (that is used only for pure gold). Maintain a propane torch flame on top till it solidifies.
4-Mark it with an hydraulic press (made with an hydraulic car jack) and a steel stamp with your seal, and whatever markings you want.
5-Weight the bar in an accurate balance, and file off less than~1 gram from it, till the weight is 1000.5 grams +/-.
**********************************************
Your process is fine. Glass with nitric parting is for amateurs.

I agree with the above.
304L or 304 SS reactor is a very worthy choice for nitric digestion.
Naturally, SS corrode. the lower the concentration of the acid the faster it corrode.
The corrosion rate of 304L and 304 according to BSSA is 0.1mm per year at 40% concentration and at 110C....

That means, 0.1mm will corrode over a year if the reactor would work 24/7 at 110C... that's the way i understand it.

You should consider adding overhead stirring (vigorous) to your reactor or produce very small beads to leach (search "atomizer" here on the forum).
This way, you will expose more surface to the acid.

 

[hrushi]

You could try washing your gold powder through hot hydrochloric so long as you rinse it well with water only a little of the value could dissolve and it could be tested using stannous, this might remove some of the contaminants but obviously you would have to use something other than stainless preferably glass.

this worked for me I took 50ml of HCL added to 500 ml water and risen gold sand and after wards I added SMB so that if any gold dissolved in HCl will precipitate. And color which I got was also good with nice shine. if i would had done this one more time color of gold would be like 9950 1kg bar. shine was also good.
regards
hrushi

 

[hrushi]

How many times have you used the same silver to inquart?

It is possible it has accumulated enough contaminants to be less than effective.

Inquarting as the sole means of refining seems a common short cut in India. Is there a reason you don't finish the job of refining with aqua regia?

Silver can be used again n again no problem.
reason to use this process is all gold is recovered at end of every process. even if u have 5 kg of gold it can be refined in max 4 hours all metal out and melted.
no fear of Aucl be wasted (no gold is wasted)
only drawback lot of silver is required.
regards
hrushi

 

[hrushi]

I dosen't matter what the XRF results are, if you have oxides on your melt you have impurities. Have an assay done and you will see how accurate the XRF is. Why would anyone go through all the trouble to inquart just to half ass the job at the end?
P.S. Get rid of the SS and get some glass.

the only reason In use SS instead of glass is it wont break or there wont be any damage.
hrushi

 

[hrushi]

Courtesy of 4metals: Flux to get approx. ~9995 gold after silver inquarting + nitric.

This is the formulation for the flux to scavenge silver and base metals.

Gold Melting Flux
This is for gold from the nitric parting process

2 pounds Anhydrous borax glass (no waters)
1 pound Soda Ash
1 pound Diatomaceous earth (silica)
1 pound Manganese Dioxide
¼ pound Flurospar (calcium fluoride)
¼ pound Calcium oxide (CaO, Lime, Type S, Unslaked)

Premix all of the ingredients and store it in a closed container. It is anhydrous and will pick up moisture from the air which will make it spit.

Add equal volume of gold sponge to flux and premix before melting.

**********************************************
How to make and stamp a 1 Kilo gold bar. Courtesy of Chloroauric Acid :

1-Weight exactly 1001 grams of pure gold (~9995 from above procedure) in pellet / shot form.
2-Melt it WITHOUT borax or any other flux in a silicon carbide or graphite crucible (that is used only for pure gold), reach a good 1,200 C.
3-Pour it in a preheated graphite mold (that is used only for pure gold). Maintain a propane torch flame on top till it solidifies.
4-Mark it with an hydraulic press (made with an hydraulic car jack) and a steel stamp with your seal, and whatever markings you want.
5-Weight the bar in an accurate balance, and file off less than~1 gram from it, till the weight is 1000.5 grams +/-.
**********************************************
Your process is fine. Glass with nitric parting is for amateurs.

I agree with the above.
304L or 304 SS reactor is a very worthy choice for nitric digestion.
Naturally, SS corrode. the lower the concentration of the acid the faster it corrode.
The corrosion rate of 304L and 304 according to BSSA is 0.1mm per year at 40% concentration and at 110C....

That means, 0.1mm will corrode over a year if the reactor would work 24/7 at 110C... that's the way i understand it.

You should consider adding overhead stirring (vigorous) to your reactor or produce very small beads to leach (search "atomizer" here on the forum).
This way, you will expose more surface to the acid.

Is there any metal which can be used instead of SS
hrushi

 

[hrushi]

It sounds like you are inquarting, dissolving in nitric, then melting the undissolved material. If this is what you are doing your gold still has impurities, red is most likely copper. There are no shortcuts if you want good purity, AR is your friend.

I have checked purity on XRF and spectrophotometer it ranges from 99.74% to 99.96%.
thing that you have boil it minimum 2 times in nitric acid after 1 reaction is complete.
I am sure you will achive purity.
if you do reaction in glass beaker you would get very nice color of gold as well
there are two disadvantage of this process
1. lot of Ag is required and again we have to recover Ag.
2. if reaction is done in SS vessel gold gets some kind of red color on top of gold and id ammonium chloride that red color goes as well to some extent but you dont get 1kg 99.50 gold bar color.

thanks
hrushi

Courtesy of 4metals: Flux to get approx. ~9995 gold after silver inquarting + nitric.

This is the formulation for the flux to scavenge silver and base metals.

Gold Melting Flux
This is for gold from the nitric parting process

2 pounds Anhydrous borax glass (no waters)
1 pound Soda Ash
1 pound Diatomaceous earth (silica)
1 pound Manganese Dioxide
¼ pound Flurospar (calcium fluoride)
¼ pound Calcium oxide (CaO, Lime, Type S, Unslaked)

Premix all of the ingredients and store it in a closed container. It is anhydrous and will pick up moisture from the air which will make it spit.

Add equal volume of gold sponge to flux and premix before melting.

**********************************************
How to make and stamp a 1 Kilo gold bar. Courtesy of Chloroauric Acid :

1-Weight exactly 1001 grams of pure gold (~9995 from above procedure) in pellet / shot form.
2-Melt it WITHOUT borax or any other flux in a silicon carbide or graphite crucible (that is used only for pure gold), reach a good 1,200 C.
3-Pour it in a preheated graphite mold (that is used only for pure gold). Maintain a propane torch flame on top till it solidifies.
4-Mark it with an hydraulic press (made with an hydraulic car jack) and a steel stamp with your seal, and whatever markings you want.
5-Weight the bar in an accurate balance, and file off less than~1 gram from it, till the weight is 1000.5 grams +/-. :lol:
**********************************************
Your process is fine. Glass with nitric parting is for amateurs.

thank you
I will try and post my reply
hrushi

 

[Dr. Poe]

In jewelry casting, the reddish surface coat is due to traces of copper contamination. The copper oxide is polished away with fine grit on a buffing wheel. In the South African Rand, ingots of gold are polished by a large flame from a torch immediately after pouring (while the ingot is still hot). The inner part of the flame is a reducing flame and robs the trace copper oxide of it's oxygen (removing the red hue). Sometimes the simplest answers are the best. Regards; Dr. Poe 8)