bombing water

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Jewelers used bombing solution to polish the gold because it uniformly removes a thin layer of metal from all exposed surfaces. By bombing before polishing the jeweler was able to retain a little more of the customers gold than by polishing alone.

Classically bombing is a mixture of potassium cyanide and hydrogen peroxide in water and the concentration of cyanide is high.

To recover the gold raise the pH to 12 with caustic soda and sprinkle in fine mesh powdered zinc dust, roughly 2 ounces for every ounce of gold you expect to recover. The gold will drop out pretty quickly and you will see the mud in solution go from brown to grey when it is complete. Filter the solids and you will have a mixture of zinc dust and precipitated gold. Rinse this well and if possible add hot water and boil it for a while to expel any cyanide. You can dissolve the excess zinc using HCl but be careful and do it upwind or in a hood to make sure you don't breathe in any fumes when you acidify what may contain residual cyanide.

Cyanide is nasty stuff and not easily neutralized without testing equipment. Adding bleach to neutralize is better than nothing but not the best solution. Cyanide is best decomposed in a 2 step process requiring both pH monitoring and ORP monitoring probes. whomever told you it can go down the drain was not helping you much!!! 4metals
 
Hi, i have this questions: does it matter if i have the caustic soda in solution? and the zinc dust is to precipitate gold or just to boost?
 
hi Mr palladium i need help i have plating water and contain 24-k gold and cyan-our,nitric acid,and b sulfate how i wanna get gold back.
 
Since urea is used to neutralize the acid (Aurochloric) wouldn't another base like sodium bicarb, calcium carbonate work as well?
 
Palladium said:
Jewelers used bombing solution to polish the gold because it uniformly removes a thin layer of metal from all exposed surfaces. By bombing before polishing the jeweler was able to retain a little more of the customers gold than by polishing alone.

Classically bombing is a mixture of potassium cyanide and hydrogen peroxide in water and the concentration of cyanide is high.

To recover the gold raise the pH to 12 with caustic soda and sprinkle in fine mesh powdered zinc dust, roughly 2 ounces for every ounce of gold you expect to recover. The gold will drop out pretty quickly and you will see the mud in solution go from brown to grey when it is complete. Filter the solids and you will have a mixture of zinc dust and precipitated gold. Rinse this well and if possible add hot water and boil it for a while to expel any cyanide. You can dissolve the excess zinc using HCl but be careful and do it upwind or in a hood to make sure you don't breathe in any fumes when you acidify what may contain residual cyanide.

Cyanide is nasty stuff and not easily neutralized without testing equipment. Adding bleach to neutralize is better than nothing but not the best solution. Cyanide is best decomposed in a 2 step process requiring both pH monitoring and ORP monitoring probes. whomever told you it can go down the drain was not helping you much!!! 4metals
Hi mr palladium

is this gold recovery process can apply with sodium cyanide and hydrogen proxide leach ?

Thanks

Regards

Sent from my GT-I9060 using Tapatalk
 
muhammad Shahzad said:
anachronism said:
You're asking the same question in many places Sir.
So what is the answer

Sent from my GT-I9060 using Tapatalk

The answer right now is, stop posting all over the place and be patient.
People don't want to answer your question, only to find that someone else already did in another post.
Be considerate.
 
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