processing residues from an old cyanide leach tank

[mlgdave]

i know that without seeing the actual material it may be hard to give me input on this but I have an opportunity to clean out an old leach tank and process the material to extract the PM's. I will be cleaning this sucker with power wire brushes, taking the rust, flaking paint, residual dirt etc etc. I have done a blended assay on the material and its showing just north of 20 oz per ton, I expect to get about 1/2 ton of material (55 gallon drum full or more). Does anyone have any input into what would be the best way to even begin to think about this material?

I would get 50% of the return to do the work

mlgdave

 

[Barren Realms 007]

Do a search and you should find what you are looking for here on the forum.

 

[mlgdave]

thanks barren!

mlgdave

 

[Oz]

Mlgdave,

I do not remember your particular situation ever being discussed on the forum. I did a quick search and found little. I am curious how these residues were formed though. Are they some of the leached materials left behind, dried cyanide solution, or some of both? Perhaps a better description of what was being done as to material and method before you showed up to take your sample would get you better help.

Goldsilverpro probably has more experience than anyone else here in using cyanide. Perhaps searching just “cyanide” with him as the author you could get some information that may be useful but it is 196 posts and as I said I do not remember “cyanide tank residue” being discussed. http://goldrefiningforum.com/phpBB3/search.php?keywords=cyanide&terms=all&author=Goldsilverpro&sv=0&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

 

[goldsilverpro]

If the residue is dried out cyanide solution and it still contains either sodium or potassium cyanide, it may dissolve in a little hot water. I would try this first. If this works, you could raise the pH to 12 with sodium hydroxide and then drop the gold with zinc dust. I would work with very small samples - say, 5 grams.

I would probably not use any mechanical cleaning methods that would produce dust. It only takes a few milligrams to kill you.

 

[Irons]

Make sure you have plenty of ventilation and wear a scott pack if you can. Working with cyanide in an enclosed area like that can be lethal.

http://www.scotthealthsafety.com/