gold ore heap leaching process

Gold ore heap leaching process: a solution for the economic and efficient development of low-grade gold ores

Gold heap leaching is a low-cost gold extraction process that dissolves and recovers gold by spraying the crushed ore heap with cyanide solution. The heap leaching processis particularly suitable for processinglow-grade gold ores,small ore bodiesandsurface oxidized ores, and has the significant advantages of low investment, low cost, adaptability, environmental control, etc. It is an ideal choice for the development of small and medium-sized gold mines.

First, the core of the heap leaching process of gold ore

1. Ore preparation system

   • Crushing and screening: two-stage crushing (jaw + cone) is used to crush the ore to -30mm to ensure permeability.

   • Pelletizing (optional): For ores with high fines content, cement (2-5kg/t) or lime is added for pelletizing to improve permeability.

2. Yard construction system

   • Bottom mat paving: 1.5-2.0mm HDPE impermeable membrane is used to pave the bottom mat with a slope of 1-3% to ensure solution collection.

   • Pile construction: Slope type or multi-layer stacked pile construction is adopted, the pile height is usually 3-8 meters, and the special pile construction machine ensures the uniformity of the pile.

3. Spraying leaching system

   • Spraying network: Install rotating spray nozzles with spraying intensity of 5-15 L/h-m² to ensure uniform distribution of the solution.

   • Leaching solution management: sodium cyanide concentration 0.05-0.1%, pH 10-11 (lime adjustment), leaching cycle 30-90 days.

4. Precious liquid recovery system

   • Precious liquid collection: Precious liquid is gathered to the precious liquid pool through the bottom mat, and the pool body is impermeable with HDPE.

   • Gold recovery process:

     • Activated carbon adsorption (commonly used): 3-5 adsorption columns are connected in series, and the grade of gold-carrying carbon can reach 3000-6000g/t.

     • Zinc powder replacement: suitable for precious liquid with high gold grade (gold>5g/m³).

5. Gold-carrying carbon treatment system

   • Desorption and electrolysis: high temperature and high pressure desorption ( 150℃, 0.5MPa ), desorption rate>98%, electrolysis of gold slime.

   • Carbon regeneration: after desorption, the poor carbon is acid washed and thermally regenerated ( 700-750℃ ) and then recycled.

6. Tailings treatment system

   • Washing and Neutralization: The tailing slag is washed with water to neutral, and the residual cyanide is <0.5mg/L.

   • Tailings disposal: harmless tailings are sealed on site or reclaimed.

Second, gold heap leaching process technology advantages

1. Low investment cost

   • The investment is only 1/3-1/5 of the traditional processing plant.

   • Simple equipment, low capital cost

2. Low production cost

   • Production cost of 30-60 RMB per ton of ore

   • Gram of gold production cost <200 yuan

3. Strong adaptability

   • Can process low grade ore with grade 0.5-1.5g/t.

   • Low terrain requirements, suitable for mountainous operation

4. Controllable environmental protection

   • Closed circuit solution circulation, no external discharge

   • HDPE impermeable, no groundwater pollution

5. Easy to operate

   • Simple process, easy to operate

   • High degree of automation, less labor

Applicable Ore Types

1. Low-grade oxidized ore

   • Oxidized ore with 0.5-1.5g/t gold grade

   • Surface weathered ore

2. Small ore body

   • Small ore bodies with an ore volume of 100,000-500,000 tons

   • Mountain mines unsuitable for plant construction

3. Difficult to process resources

   • Old tailing ponds

   • Residual ore from abandoned mines

IV. Key Equipment Configuration

V. Whole process integrated technical service
We provide the whole chain of gold mine CIL technical support from process design to after-sales service, specifically including:

• Process and engineering design
  Covering process development, equipment selection, site planning, drawing design and special design of seepage control and solution circulation system.

• Equipment supply and integration
  Including equipment production, engineers' door-to-door installation and commissioning guidance.

• Production support and training
  Provide operator training, production parameter optimization and real-time technical guidance.

• Environmental Solutions
  Covering the harmless treatment of tailings, wastewater treatment and other solutions to meet the standards.

• After-sales service
  Provide equipment maintenance, operation guarantee and technology upgrading services on an ongoing basis.

We are committed to ensuring the efficient landing and long-term stable operation of the project through end-to-end integrated services.

The gold heap leaching process is an excellent choice for the economic development of low-grade gold mines. For customized gold ore heap leachingsolutions or technical consultation, please contact us for professional solutions.