There are various methods for extracting gold from gold ores, such as gravity separation, flotation, cyanidation, amalgamation, etc. Among them, two commonly applied methods are flotation and cyanidation. The CIP (Carbon-In-Pulp) process is named after its main steps, which are carbon-in-pulp and cyanidation.
The goal of the CIP process is to extract gold from gold-bearing ores, dissolve it, adsorb it onto activated carbon, and ultimately desorb and recover the gold.
Crushing and Grinding: The ore undergoes initial crushing and grinding to reduce the particle size of the ore, making it more amenable to cyanidation treatment. Equipment such as crushers and ball mills are typically used for this purpose.
Leaching: During the leaching step, the ore is immersed in a water solution containing cyanide reagents. This process dissolves gold from the ore, forming a cyanide solution with gold.
Cyanidation: The gold-containing cyanide solution is further processed to ensure complete dissolution of gold. This often involves contact with oxygen, which aids in promoting gold dissolution. Cyanidation is the process of converting sulfide gold into water-soluble cyanide gold.
Adsorption: The dissolved gold ions are then adsorbed onto activated carbon. Activated carbon is a porous material with significant adsorption capacity, effectively trapping gold.
Separation: Separation processes are used to separate gold-loaded activated carbon and the cyanide solution from the ore. These steps usually include screening, precipitation, and washing to ensure complete separation of gold from the activated carbon.
Desorption and Recovery: Gold-loaded activated carbon is then sent to the desorption step. Typically, gold is desorbed by heating and washing the activated carbon with gas or chemical solutions. This separated gold can be further refined and smelted.
Waste Handling: The process generates waste, including unextracted ore residues and spent activated carbon. These waste materials must be properly handled and disposed of to minimize environmental risks.
Crushing and Grinding Equipment
Crusher: Used for reducing the size of the raw ore.
Ball Mill or Grinding Mill: Used for further ore size reduction to increase gold exposure.
Leaching Equipment
Soaking or Reaction Tanks: Used for immersing the ore in a cyanide solution.
Agitators or Gas Injection Systems: Used for agitation and aeration to ensure gold dissolution.
Cyanidation Equipment
Oxygen Supply System: Provides oxygen to facilitate gold dissolution.
Cyanidation Tanks: Used for the reaction of the ore with the cyanide solution.
Adsorption Equipment
Activated Carbon Tanks: Used for gold ion adsorption by activated carbon.
Agitators: Ensures even adsorption of gold onto the activated carbon.
Separation Equipment
Precipitation or Separation Tanks: Separates gold-loaded activated carbon and cyanide solution from the ore.
Filter Cloth or Filter Press: Used for further separation and drainage.
Screening Equipment: Separates solid and liquid components.
Desorption and Recovery Equipment
Desorption Tanks: Used for gold desorption from activated carbon.
Condensers: Cools and condenses desorption solution.
Smelting Equipment: Used for further purification and smelting of recovered gold.
Waste Handling Equipment
Precipitation Tanks: Used for handling waste cyanide solution and wastewater.
Stacking Equipment: Used for managing unprocessed ore residues.
Monitoring and Control Systems
Instruments and Sensors: Monitor process parameters such as temperature, pressure, flow, etc.
Control Systems: Automate the process steps to ensure stability and safety.
As modern industry advances, CIP gold processing plants are typically highly automated and integrated. They require careful design and maintenance to ensure efficient gold extraction and safe operation. The specific process and equipment selection for a CIP gold processing plant should be based on the results of ore testing and should follow the process flow.
