The core difference between Carbon-In-Pulp (CIP) and Carbon-Leach-In (CIL) processes lies in the sequence of gold ore leaching and adsorption: CIP is a step-by-step process, leaching followed by adsorption; CIL, on the other hand, is simultaneous, with leaching and adsorption occurring concurrently.
I. Process Flow Comparison
CIP (Carbon-In-Pulp): The ore is first fully leached in a cyanide tank, then the slurry is gradually mixed with activated carbon in multi-stage stirred tanks. The adsorption process is broken down into 7-9 gradient adsorption units connected in series, each equipped with an independent carbon-in-pulp separation system.
CIL (Carbon-Leach-In): Coconut Shell Activated carbon particles are simultaneously added to the cyanide leaching tank, allowing gold ore leaching and adsorption to occur concurrently. After the slurry is mixed with the sodium cyanide solution, the activated carbon directly enters the reaction system, adsorbing dissolved gold-cyanide complexes in real time.
II. Technical Comparison
CIP: Employs independent adsorption tank groups. The slurry flows sequentially through each stage of stirred tanks (single tank residence time 45-60 minutes), while the activated carbon flows counter-currently to create a concentration gradient.
Precise control of the slurry flow rate (typically 0.8-1.2 m³/min) and carbon movement frequency in each unit is required, placing higher demands on the automated control system.
Pre-oxidation treatment can be performed in the independent adsorption stage, such as adding hydrogen peroxide (0.05-0.1% concentration) to the secondary tank to degrade organic interferences.
CIL (Clean Leaching Intake): The activated carbon must withstand high-intensity mechanical stirring and chemical corrosion in the leaching tank. High-strength coconut shell activated carbon (3-6 mm particle size) must be selected, and a carbon concentration of 12-15 g/L must be maintained per ton of slurry.
The adsorption system needs to be equipped with wear-resistant carbon extraction screens and an online gold analyzer for real-time monitoring to balance the leaching rate and adsorption load.
Because leaching and adsorption occur simultaneously, clay minerals in the slurry easily adhere to the surface of the activated carbon, causing "passivation." Regular high-temperature alkaline washing (4% NaOH solution, 85℃) is required to restore carbon activity.
III. Comparison of Applicable Scenarios
CIP: Particularly suitable for processing high-grade ores with stable composition, improving adsorption efficiency through staged adsorption.
Suitable for processing amalgamation tailings, gravity separation tailings, or argillaceous oxidized ores, with recovery rates exceeding 90%.
CIL: Suitable for low-grade ores with fluctuating gold content, shortening the overall reaction time by simultaneously performing leaching and adsorption.
For difficult-to-process ores containing arsenic, antimony, or other substances that easily form complexes (such as Carlin-type gold deposits), the simultaneous reaction of CIL can suppress the impact of harmful ions on leaching efficiency.
