Eco-friendly mining

Let us explain the CIL mining process now

The Carbon In Leach (CIL) mining operation which is today the most advanced gold extraction process.

A CIL Gold Recovery Plant approximately recovers 85% of the gold is passed in the plant. From the ball mill, slurry is pumped to the CIL leach tanks where lime adjusts the pH, if necessary, and it is stirred for the specific period of time.

Air is added to increase the reaction rate and shorten the leaching time. Cyanide is added in the first tank. Each carbon leach tank has a screen in it for carbon retention. Slurry can gravity flow between tanks or be pumped. Dipending on the Leaching time, normally there are 4 to 6 tanks in series. From the first tank, the loaded carbon is pumped using a impeller pump (to not degrade the carbon), to a loaded carbon screen, where the slurry passes through the screen and retains the carbon.

Then the carbon is sent to the carbon stripping process. This can be either at atmospheric pressure of a higher pressure. The higher pressure Zadra method takes less time for stripping and is popular, for that reason. The stripping solution is typically a heated solution of cyanide and sodium hydroxide. Stripping can take a couple of hours. Then, the pregnant concentrated solution is pumped to the electrowinning cells, where the precious metals plate onto the cathodes, which are steel or stainless steel wool.

This thickener is used to maintain a constant percentage of solids in the ore, therefore needing and utilizing less water used in the process, smaller tanks and a smaller water source. The control over the process is greater and optimized over older plants with older technologies such as conventional CIL plant without a thickener. The Leaching process is therefore reduced by 20% bringing us to a leaching time of in 8-13 hours.

All these help us to execute mining on very high Eco standards which is good for both: business and planet 🌎

Stay tuned to know more about GoldeNugget and be a part of revolution in gold-mining with us!