Summary：This professional guide demystifies the four mainstream gold beneficiation process methods—Gravity Separation, Flotation, Cyanidation (Leaching), and Combined Process Flowsheets.
Gold ore processing is the core step that determines gold recovery, operating cost, and overall project profitability. Selecting the right gold ore processing method is not only a metallurgical decision, but also a strategic investment choice that directly impacts plant performance, environmental compliance, and long-term returns.
In nature, gold ore is primarily categorized into three types: lode gold (vein gold), placer gold, and associated gold ore. In practical mining operations, gold ores vary significantly in mineral composition, gold particle size, oxidation degree, and association with gangue minerals. As a result, no single gold ore processing method fits all deposits. An effective gold ore beneficiation solution must be designed based on ore characteristics, production targets, and site conditions.
This professional guide demystifies the four mainstream gold beneficiation process methods—Gravity Separation, Flotation, Cyanidation (Leaching), and Combined Process Flowsheets. We analyze each method across five key dimensions—principle, applicable ore types, core process, main equipment, and process characteristics—providing clear structure and essential knowledge for both beginners and industry professionals.
1. Gravity Separation Method
Principle: As one of the earliest and most cost-effective gold ore processing methods, gravity separation utilizes the density difference between gold and gangue minerals to achieve separation without chemical reagents.
Applicable Ore Types: Particularly suitable for placer gold deposits, and vein gold ores where gold grains are coarse and unevenly disseminated (e.g., some gold-bearing quartz veins).
Core Process Flow:
- Run-of-mine ore crushing and screening
- Classification and desliming
- Gravity concentration using jigs, shaking tables, spiral chutes, or centrifugal concentrators
- Production of heavy mineral concentrate
In many gold beneficiation plants, gravity separation is integrated into the grinding circuit to recover coarse liberated gold as early as possible.
Main Equipment: Jaw Crusher, Cone Crusher, Jig, Shaking Table, Spiral Chute, Centrifugal Concentrator. These can be used individually or in combination.
Process Characteristics:
- Advantages: Simple process, low cost, no chemical pollution, and high efficiency in recovering coarse gold.
- Limitations: Poor recovery for fine and ultrafine gold particles.
- Typical Application: Often serves as a pre-concentration step at the front end of combined flowsheets, or for the roughing of placer gold.
2. Flotation Method
Principle: Utilizes differences in the surface properties of gold minerals (especially gold associated with sulfides). Through the use of reagents, target minerals are made to attach to air bubbles and float, achieving separation and concentration.
Applicable Ore Types: Primarily treats vein gold ores where gold is closely associated with sulfides (like pyrite, chalcopyrite), and gold-bearing polymetallic sulfide ores.
Core Process Flow:
- Multi-stage Crushing & Screening of run-of-mine ore
- Grinding
- Pulp Conditioning & Reagent Addition (collectors, frothers)
- Flotation Separation (Rougher, Cleaner, Scavenger stages)
- Production of a Gold-Bearing Sulfide Concentrate (requires further processing to final gold).
Main Equipment: Jaw Crusher, Cone Crusher, Ball Mill, Mechanical Agitation Flotation Cell (most widely used), Flotation Column (suitable for fine particle separation).
Process Characteristics:
- Advantages: Excellent concentration effect and high recovery for fine gold, enables comprehensive recovery of multiple metals.
- Limitations: Cannot directly produce final gold product.
- Typical Application: Often the core unit in combined processes like Flotation-Cyanidation, or used independently for simple sulfide ore separation.
3. Cyanidation (Leaching) Method
Principle: In an alkaline, oxygenated environment, a cyanide solution dissolves gold to form a gold-cyanide complex. Gold is then recovered via adsorption or displacement, allowing for the direct production of final gold.
Applicable Ore Types: Ores with high oxidation levels and finely disseminated gold, containing little to no impurities like copper or arsenic that interfere with cyanidation.
Core Process Flow:
Two main approaches exist:
① Whole Ore Cyanidation: Ore is finely ground to specification → Cyanide Leaching → Adsorption/Displacement → Elution & Electrolysis → Smelting to gold.
② Concentrate Cyanidation: Only the flotation concentrate is reground before undergoing the above leaching process, making it more energy-efficient.
Main Equipment: Jaw Crusher, Cone Crusher, High-Pressure Grinding Rolls (HPGR), Ball Mill, Leaching Tanks, Adsorption Columns, Elution & Electrolysis Unit, Merrill-Crowe Zinc Precipitation Box. Auxiliary equipment ensures stable and efficient operation.
Process Characteristics:
- Advantages: High leaching rate, mature technology, direct gold production.
- Limitations: High toxicity of cyanide, demanding stringent environmental and safety controls.
- Future Trend: Focus on promoting low-toxicity/non-cyanide gold leaching reagents.
4. Combined Gold Ore Processing Flowsheets
For complex, refractory gold ores, a single process is often insufficient for efficient recovery. Combining processes maximizes both recovery rate and economic benefit. Two mainstream combinations are prevalent.
(I) Gravity-Flotation Combined Process
Principle & Application: Gravity separation recovers coarse gold, while flotation recovers fine gold and gold in sulfide minerals from the gravity tailings. It is adapted for complex ores with unevenly disseminated gold of varying grain sizes.
Core Process Flow: Ore Crushing & Screening → Gravity Separation (coarse gold recovery) → Tailing Fine Grinding → Flotation (fine gold recovery) → The two concentrates are processed separately to final gold.
Characteristics: Recovers both coarse and fine gold, offers high recovery and flexible flow, with slightly higher equipment investment but superior overall economics.
(II) Flotation-Cyanidation Combined Process
Principle & Application: Flotation first enriches gold into a concentrate, which is then treated by cyanidation leaching. This is suitable for complex ores where gold is mainly hosted in sulfides and is a mainstream industry flowsheet.
Core Process Flow: Ore Crushing & Grinding → Flotation (gold concentrate production) → Concentrate Regrinding (liberation enhancement) → Cyanidation Leaching & Gold Extraction → Tailings disposal; If the concentrate contains interfering impurities, pre-treatment like roasting may be required.
Characteristics: High comprehensive recovery rate, reduces cyanide consumption and environmental pressure, suitable for complex refractory sulfide ores. It involves higher process and equipment investment but offers stable recovery performance.
This flowsheet is one of the most widely adopted gold beneficiation solutions in modern gold processing plants.
How to Select the Right Gold Ore Processing Solution
Selecting the optimal gold ore processing method requires a systematic evaluation of:
- Gold ore type and mineral composition
- Gold particle size and liberation characteristics
- Oxidation degree and impurity content
- Target capacity and recovery rate
- Environmental and regulatory requirements
A professionally designed gold ore beneficiation solution integrates metallurgical testing, equipment selection, and process optimization to ensure stable operation and long-term profitability.
Complete Gold Ore Beneficiation Solutions for Your Project
We provide customized gold ore processing solutions, covering:
- Process flowsheet design
- Equipment selection and supply
- Plant layout and capacity planning
- Commissioning and technical support
Whether you are developing a new gold project or upgrading an existing beneficiation plant, our experienced engineering team delivers reliable, efficient, and economically optimized gold processing solutions tailored to your ore characteristics.
Contact us today to receive a professional evaluation and customized gold beneficiation flowsheet for your project.
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