Sciencemadness Discussion Board

cyanide usage for gold leaching

blackwolf365 - 24-7-2019 at 05:17

greeting all.

first off, let me say that yes, i fully realize and accept how dangerous cyanide is. but, as it can improve the expedience of the gold refining process, i figured it was at least worth looking into

ive been researching ways to extract and refine gold from computer parts. during this research, i discoverd that cyanide can be used to great effect for this purpose.

i also learned that you can keep the cyanide basic by adding sodium hydroxide. but i cannot seem to find what the proper ratios are for this. can anyone point me in the right direction? for the proper ratios and sources of these 2 chemicals.

RedDwarf - 24-7-2019 at 13:44

What's your rationale for going with a cyanide route rather than a non-cyanide route. How much do you expect to improve yield / save time, and does that really make it worthwhile? Have you thought about how you're going to dispose of the waste?

blackwolf365 - 24-7-2019 at 15:34

haven't looked into disposal yet. haven't decided if i want to go that route. and my rational is expedience and efficiency. i want to get it as pure as i can as efficient as i can and as fast as i can.

as it stands now, when circumstances allow, i'm gonna start by trying some saltwater cells and see how successful i am with that. goal is to get it to 99.5% pure, which is the international standard, i believe.

as for why i asked this questuion: to find pricing and sources so i can see a basic idea of the cost.

draculic acid69 - 25-7-2019 at 02:11

Use bleach in large amounts to dispose of waste and wash glassware or clean up a spill

blackwolf365 - 27-7-2019 at 18:22

the use of bleach has already come up in my research. i just want to, if i do use cyanide, to take as little cance with it as possible.

being a rather toxic and deadly thing, in the right form, gives me great pause for cosideration. cyanide can be some scary stuff.

metallurgist - 3-8-2019 at 06:22

keep the solution above pH 10 to inhibit HCN forming.

There are many other metals that form complexes with CN.. you may want to separate these beforehand...

ZetekitoxinAB - 4-8-2019 at 08:26

I dont know what is all this fuss about cyanide, to be honest. There is no better reagent than it to complex gold, but it also needs oxygen from the air; I think you could speed up the process a lot by adding dilute H2O2 in small quantities. Just wear gloves, work in a well ventilated, secure area and keep it away from acids. After you recover gold by precipitation with Zn dust for example, just destroy the remaining solution with bleach. I believe dilute cyanide works very well, especially if left a reasonable time to react.

RogueRose - 4-8-2019 at 15:10

Quote: Originally posted by ZetekitoxinAB  
I dont know what is all this fuss about cyanide, to be honest. There is no better reagent than it to complex gold, but it also needs oxygen from the air; I think you could speed up the process a lot by adding dilute H2O2 in small quantities. Just wear gloves, work in a well ventilated, secure area and keep it away from acids. After you recover gold by precipitation with Zn dust for example, just destroy the remaining solution with bleach. I believe dilute cyanide works very well, especially if left a reasonable time to react.


I've always heard people using zinc dust but would pieces of zinc work as well, maybe small pellets? I know a lot of people probably have access to zn pellets vs dust. I would think it would just take longer and maybe if you did this on a magnetic stirrer it would speed up the process. The only issue I see is if an oxide layer forms on the zinc, like a passivation layer.

johny5 - 6-8-2019 at 01:39

You are required to keep a PH above 10 to do so.

metallurgist - 11-8-2019 at 07:23

Merrill-Crowe process - requires a vacuum to remove dissolved air.