Error creating thumbnail: Unable to save thumbnail to destination
|This article is a stub. You can improve Gold Refining Wiki by expanding it.|
Oxalic acid, (C2H2O4), is an organic acid found in some plants, for example rhubarb. In refining it is used for precipitate gold from solution. It demands a bit more work to use compared to SMB or copperas but has a reputation to produce very clean gold.
Oxalic acid is also used in lanthanide refining.
( Main article : Precipitating gold with oxalic acid)
Oxalic acid can be used to precipitate gold from solutions. It is a good precipitant to separate gold from PGM:s in solution. It has a slight drawback of also precipitate tin and copper, but if SMB or sulfur dioxide is used in a second refining a lot of the contaminants can be removed. Instead of a second refining, good washing can be used to remove any contaminants.
It is also used in bromate hydrolysis to remove gold from platinum solutions.
- Samuel-a : Gold Reduction with Oxalic Acid - Complete Process
- Kadriver : Gold Refining Precipitating Gold With Oxalic Acid
Oxalic acid has a LD50 of 0.6g/kg, a lethal oral dose is about 15-20 grams. The toxicity comes from precipitated calcium oxalate in the kidneys, leading to kidney failure.