How to Choose a Colloidal Gold Production and Mineral Processing Plan and a Complete Set of Equipment?

The common characteristics of these four types of ores are: fine gold particles, complex occurrence patterns, and the inability to achieve complete recovery using a single process. The core of process design is not “which piece of equipment to buy,” but rather to first thoroughly understand the occurrence patterns of the gold before determining the process route.

Option 1: Flotation Enrichment + Pretreatment + Cyanidation (Suitable for micro-fine-grained disseminated or arsenic- and carbon-bearing ores)

This is the mainstream route for Carlin-type ores and difficult-to-process arsenic- and carbon-bearing ores.The logic is as follows: First, use flotation to concentrate gold-bearing sulfides into a concentrate, significantly reducing the feed volume for subsequent pretreatment; then, perform pretreatment on the concentrate (using proprietary reagents, roasting, pressurized oxidation, bio-oxidation, etc.) to release the bound gold; finally, recover the gold through cyanidation.

Key points:

• The grinding fineness must ensure the individual liberation of gold-bearing sulfides, but there is no need to pursue “the finer, the better”; over-grinding increases sludge formation and reagent consumption;
• The flotation reagent regime determines the concentrate grade and sulfur recovery rate; for arsenic-bearing ores, realgar must be suppressed or the arsenic-gold concentrate must be floated separately, while for carbon-bearing ores, the gold-snatching effect of carbonaceous matter must be suppressed;
• The choice of pretreatment method depends on the arsenic/carbon content and their occurrence conditions, and directly determines economic viability.

Option 2: Gravity Separation + Cyanidation Combination (Suitable for iron-capped and colloidal oxidized ores)

Gravity separation recovers coarse-grained free gold early in the grinding circuit to prevent loss due to overgrinding; gravity separation tailings are fed into the cyanide leaching process to recover fine-grained gold. The porous structure of limonite facilitates leachate penetration, but when clay content is high, the slurry rheology must be improved using dispersants or granulation.

Option 3: Whole-ore Cyanidation (CIL/CIP) (Suitable for ores where gold is predominantly in a free state, with simple gangue and no interfering elements)

If laboratory analysis confirms that gold is predominantly in a free state and the ore contains no interfering elements such as arsenic, carbon, or antimony, direct whole-ore cyanidation is the most straightforward approach. CIL (Cyanide In-Leach) combines leaching and absorption in a single process with a compact flow scheme, making it suitable for small- to large-scale processing plants; CIP (Cyanide In-Leach and Cyanide In-Press) involves leaching followed by adsorption, allowing for more precise segmented control, and is commonly used in large-scale processing plants.

Option 4: Full-Process Ore Washing and Gravity Separation (Suitable for placer gold deposits and fine-grained placer gold)

Trommel screen/ore washer for ore washing and classification → chute roughing → centrifugal concentrator for enrichment → shaking table for fine selection. When clay content is high, enhanced ore washing is required; coarse-grained gold is recovered using chutes and centrifuges, while fine-grained gold is recovered via shaking tables or centrifugal scavenging.Mobile solutions are suitable for dispersed ore deposits, while stationary solutions are suitable for concentrated ore sources.

The golden rule for selecting a solution: Without laboratory analysis of representative ore samples and beneficiation tests, any equipment selection is like “a blind man feeling an elephant.” This is especially true for colloidal gold ores—even the slightest difference in the form of gold can lead to a process route that is worlds apart.

1. Crushing and Grinding Stage (The Starting Point for All Rock-Type Gold Deposits)

• Jaw Crusher: Primary crushing; handles large chunks of raw ore; simple structure and durable;
• Cone Crusher: Medium and fine crushing; highly efficient at processing hard rock with uniform product size;
• Ball Mill: Grid-type with forced discharge and high throughput, suitable for coarse grinding or the first grinding stage; overflow-type relies on gravity discharge and achieves finer grinding, suitable for fine grinding or the second grinding stage.Rock gold ore processing commonly employs a two-stage grinding process consisting of a first-stage grid-type mill followed by a second-stage overflow-type mill, with the second stage forming a closed-circuit system with a spiral classifier or hydrocyclone;
• Classification Equipment: Spiral classifiers and hydrocyclones operate in a closed-circuit system with the mill, sending qualified fine powder to the next stage and returning coarse sand for regrinding.

Adhering to the principle of “more crushing, less grinding”: the crushing stage does most of the work, while the grinding stage consumes less electricity.

2. Gravity Separation Section (Early Recovery of Coarse-Grained Gold)

• Centrifugal concentrator: Enhances gravity separation based on centrifugal principles to recover fine-grained gold, silver, platinum group metals, and other precious metals; it is the primary equipment for recovering coarse-grained free gold in the grinding circuit;
• Jig (Sawtooth Wave/Hydraulic): Processes coarse-grain material with high throughput;
• Shaking tables (6-S shaking tables/multi-deck shaking tables): Process fine-grain fractions with high separation accuracy; used for the final concentration of gravity concentrate;
• Spiral Chute: Simple in structure, suitable for roughing and tailings disposal.

Gravity separation typically does not constitute a complete processing flow for gold-bearing rock on its own, but is instead integrated into the grinding circuit or combined with flotation and cyanidation. The degree of liberation is the key indicator of gravity separation recovery; if the grinding fineness is insufficient, gravity separation is ineffective.

3. Flotation Stage (Gold-bearing sulfide ores, fine-grained disseminated ores)

• Floating Machine Series: SF-type self-priming machines, suitable for the front end of roughing and scavenging; XCF/KYF-type aerated machines, the preferred choice for large-scale direct-flow cell configurations; BF-type and JJF-type machines are selected based on throughput and aeration requirements.These can be combined into roughing, scavenging, and cleaning units (ranging from one roughing stage, two cleaning stages, and two scavenging stages to one roughing stage, three cleaning stages, and three scavenging stages);
• Supporting agitation tanks are used for reagent mixing prior to flotation, while thickeners and filter presses are used for concentrate dewatering.

The flotation method can process low-grade, fine-grained disseminated gold ores and is highly adaptable; it is one of the most widely used technologies for rock gold ore processing in China.

4. Leaching and Adsorption Section (CIL/CIP Specific)

• Leaching tank (with agitation and aeration): Sodium cyanide and lime are added to adjust the pH (10–11) and dissolve the gold;
• High-efficiency dual-impeller carbon-in-leach tank: The CIL process combines leaching and adsorption; activated carbon is added in the final tank and moves forward in a countercurrent flow;
• Activated Carbon Separator: Prevents activated carbon from being carried away with the slurry; Carbon Recoverer: Lifts and extracts gold-loaded activated carbon;
• Desorption and Electrolysis Equipment: Suitable for conventional processing at ambient temperature and pressure; high-temperature, high-pressure desorption ensures more thorough separation and is suitable for large-scale or hard-to-desorb ores;
• Gold smelting furnace: Smelts gold slurry into gold ingots;
• Zinc Powder Displacement Unit (heap leach concentrate, CCD countercurrent wash concentrate): Clarification and filtration → vacuum deoxygenation → addition of zinc powder for displacement → filtration of gold slurry → smelting.The precious metal solution must be clarified to a suspended solids level of <10 ppm and dissolved oxygen of <1 mg/L; the displacement rate is typically >99%.

5. Concentration and Dewatering Section

Thickening machines (center-driven/high-efficiency thickeners) are used for preliminary sedimentation and dewatering of concentrate and tailings; plate-and-frame filter presses compress the slurry into filter cakes and are key equipment for dry tailings disposal; dewatering screens are used for final dewatering.

6. Auxiliary Equipment

Vibrating feeders, belt conveyors, slurry pumps/carbon-lifting pumps, cylindrical ore washers/screw ore washers (for pre-treatment of ore with high clay content), and trommel screens (for gold-bearing sand processing).

Daily Processing Capacity (metric tons/day)	Price Range for Complete Set of Main Equipment (US$10,000)
30	20–35
50	25–40
100	35–50
200	45–75
300	60–90
500	90–135
800	125–170
1,000	150–190
1,500	205–270
2,000	265–335
2,500	300–380

The lower limit of the range corresponds to standard configurations, conventional oxidized gold ores or simple sulfide ores, and standard operating conditions; the upper limit corresponds to non-standard custom configurations, complex ores, special operating conditions, or more comprehensive solutions.These are only reference prices for the complete set of main equipment and do not include civil engineering, installation, or logistics. Specific quotations must be determined based on ore type, process flow, and on-site conditions.

Regarding the scope of delivery, the standard model is as follows: the supplier is responsible for process design, engineering drawings, manufacturing of core equipment, on-site installation technical guidance, integrated commissioning, and training;while the client organizes civil construction and general installation labor locally. This approach ensures technical quality is guaranteed while helping the client save significantly on costs associated with dispatching domestic workers overseas—including airfare, visas, lodging, and high daily wages. If local construction resources are truly unavailable, a turnkey solution can be negotiated.