Cil Processing Lines: Bridging Traditional and Modern Gold Extraction Techniques

Gold CIL Leaching Process Explained

CIL stands for carbon-in-leach. This is a gold extraction process called cyanidation where carbon is added to the leach tanks so that leaching and adsorption take place in the same tanks. Cyanide is used as a lixiviant to leach gold from a solid matrix, forming a gold cyanide complex which is then adsorbed onto activated carbon.

The Principle of Leaching

Leaching can be compared to brewing tea. Just as flavor dissolves into water leaving leaves behind, gold turns into liquid form using cyanide and oxygen, separating it from the waste rock. The gold then sticks to activated carbon via adsorption (positive charges attracting negative charges). Through elution and electrolysis, pure gold is finally recovered.

The CIL process is ideal for oxidized gold ore with low sulfur and mud content. It offers a shorter process flow and higher efficiency compared to traditional CIP methods. Standard conditions include a pH of 10-12 and the use of coconut shell activated carbon.

Processing Steps

• Raw Material Preparation: Crushing, grinding, and leaching.
• Leaching & Adsorption: Eight agitators work in sequence using activated carbon.
• Tail Water Treatment: Slurry is filtered; cakes are transported and water is reused.
• Carbon Treatment: Desorption and electrolysis to produce pure gold bars.