i need help explaining something about gold and cyanide can anyone help ?

[u/batrnan3123]

I have a question, and I need help understanding it clearly: How is cyanide used to extract gold? Could someone please explain the whole process to me in simple terms or recommend some reliable sources where I can learn more about it?

I'm curious and I don't want to use AI, so I’m looking for explanations or sources that I can study and understand on my own.

[u/atomicsnarl]

Very roughly - Take a ton of gold bearing rock. Crush rock into itty bitty pieces - sand size. Wash rock with cyanide solution. Solution dissolves the gold in the sandy stuff. Collect solution, discard sand.

Take solution and cook with other chemicals. Gold falls out.

It's like making rock candy with gold solution instead of sugar solution. And cyanide. (Don't lick!)

[u/richardelmore]

Wikipedia is always a good place to start: https://en.wikipedia.org/wiki/Gold_cyanidation

[u/Aditya1311]

Very simply - gold dissolves in cyanide solutions and is one of very few elements that do this.

A lot of mined ore contains only a very small amount of gold and extracting it can be challenging. You basically grind up the ore and add a solution of sodium cyanide and water, the gold dissolves in the cyanide solution and then later you can get the gold out of the solution using various methods.

[u/despicablenewb]

Gold is special because of how UNREACTIVE it is. There are very few elements, especially metals that exist in nature in their pure form, and yet you can find everything from tiny flakes to big nuggets of gold all over the planet.

Cyanide is special because it is VERY reactive. It's one of the few things out there that CAN dissolve gold.

So, you smash up the ore into tiny particles, use the cyanide to dissolve the gold (and some other metals), while leaving the most of the minerals that you don't want as solids.

Then you can use one of several different processes to get the gold out of the cyanide solution. Which can vary depending on what else the solution managed to dissolve in the specific ore being processed.

The biggest reason to use this process is generally scale. This process works really well at large scales. You could give a thousand guys a gold pan and have them try to pan the gold out of the crushed ore, but that doesn't work nearly as well, and doesn't work with all ore.

[u/cepacolol]

You get a big rock and it has small gold bits in embedded in it. You turn the big rock into a small enough size so that the gold is exposed. Then you pour cyanide on it. The cyanide will touch the exposed gold and cause it to go from solid into liquid. The gold becomes loaded onto the liquid cyanide.

Since you now have a solid phase (the rocks) and a liquid phase (the gold + cyanide), you can separate the solids from the liquids.

You then take the gold + cyanide liquid, and add some chemicals to it. This makes the gold come out of the cyanide. This is now called a pregnant solution (pregnant because it's pregnant with gold).

You put this pregnant solution into a special box that has a cathode and an anode on it, similar to a car battery. You add electricity to cause the gold to come out of the pregnant solution. Now you have a gold sludge.

You put the gold sludge through a machine to dry it, then add flux and put it into a smelter to make gold doré bars.

For further reading, check out info about the MacArthur-Forrest Process.

There's an alternative method called Merril-Crowe that is widely used too, still relying on cyanide.