Gold Carbon-in-Pulp Plant: Modern Practice of Efficient Gold Extraction Technology

I. Overview of Gold CIP Plant

The Gold Carbon-in-Pulp (CIP) plant is a modern gold extraction process based on activated carbon adsorption technology, widely used in processing gold-bearing ores. Compared with traditional cyanidation methods, the CIP process significantly improves gold recovery (up to 95%-99%) by directly introducing activated carbon into pulp to adsorb gold-cyanide complexes, while reducing production costs and environmental risks. It has become one of the mainstream technologies in global gold metallurgy.

A modern CIP plant typically consists of four modules: pretreatment system, leaching/adsorption system, elution/electrolysis system, and carbon regeneration system, achieving full-process automation from ore crushing to gold ingot production. Core advantages include:

· High adaptability for low-grade and complex ores

· Closed-circuit design minimizing cyanide discharge

· Cost efficiency through carbon reuse

II. Key Process Flow

1. Ore Preparation

(1) Crushing & Grinding
Three-stage crushing reduces ore size below 15mm, followed by closed-circuit grinding with ball mills and hydrocyclones to achieve 90% passing 200 mesh.

(2) Thickening
Slurry is concentrated to 40%-45% solids via high-rate thickeners.

2. Cyanide Leaching & Carbon Adsorption

(1) Pre-leaching
Slurry reacts with sodium cyanide (0.03%-0.1%) in agitated tanks to dissolve gold:

4Au+8NaCN+O2+2H2O→4NaAu(CN)2+4NaOH

(2) Counter-current Adsorption
Slurry flows through 6-8 adsorption tanks contacting coconut-shell carbon (1.0-3.35mm). Loaded carbon advances forward through inter-screen pumps while fresh carbon is added at the last stage.

3. Loaded Carbon Treatment

(1) Elution & Electrolysis
Acid-washed carbon undergoes pressurized elution (130°C, 0.5MPa) with hot NaOH/NaCN solution. Gold-bearing solution is electrolyzed to deposit gold sludge.

(2) Carbon Regeneration
Thermal reactivation in rotary kiln at 700-750°C restores 90%-95% adsorption capacity.

4. Gold Refining

Electrolytic sludge undergoes nitric acid purification, aqua regia dissolution, and reduction precipitation to produce 99.99% gold, cast into standard bars.

III. Technological Highlights

1.        Advanced Adsorption Tanks
Dual-impeller design enhances mixing efficiency by 15%-20%.

2.        Intelligent Control System
DCS monitors critical parameters: pH (10.5-11.0), dissolved oxygen (8-12ppm), CN⁻ concentration.

3.        Environmental Protection

· Cyanide wastewater treated to CN⁻<0.2mg/L via SO₂/air process

· HDPE-lined tailings dam with real-time monitoring

IV. Case Study

Operational data of a 2000t/d CIP plant:

V. Future Trends

1.        Nano-structured carbon for enhanced kinetics

2.        Integration of bio-cyanidation

3.        Digital twin system optimization