Application Prospects of Spiral Chute Separation Technology in Tin Ores [Indonesia Tin Industry Conference]

At the 2025 Indonesia Mining Conference & Critical Metals Conference - 2025 Southeast Asia Tin Industry Conference, hosted by SMM Information & Technology Co., Ltd. (SMM), supported by the Indonesian Ministry of Foreign Affairs as the government supporter, and co-organized by the Association of Indonesian Nickel Miners (APNI), the Jakarta Futures Exchange, and China Coal Resource, Li Chun'ou, the General Manager of Alicoco Mineral Technology Co., Ltd., delivered a speech titled "Application Prospects of Spiral Chute Separation Technology in Tin Mines."

He introduced that Alicoco Mineral Technology Co., Ltd., a manufacturing enterprise, boasts years of experience in mineral gravity separation technology. Its proprietary spiral concentrator technology offers users feasible solutions for improving mineral gravity separation processes.

Features of Spiral Chutes

Li Chun'ou, the founder of Alicoco Mineral Technology Co., Ltd., began researching the technological transformation of spiral chutes as early as 2003. He pioneered the segmented injection molding, splicing, and assembly process technology, which was granted a national invention patent. Subsequently, it was launched in the market and widely praised by mine users.

1. Modular design facilitates large-scale production, convenient transportation, and installation

With a modular design, the equipment can be disassembled into components for transportation, saving ocean freight costs, and rapidly assembled on-site at the mining area. Operators can master the equipment with just 2 hours of training, significantly reducing long-distance transportation costs and enabling high-quality, low-cost coverage of the global market.

2. Efficient separation and high recovery rate

The spiral chutes produced using injection molding methods feature a fine groove surface structure, combining smoothness and roughness to achieve efficient separation, particularly effective for fine-grained minerals (such as gold, tungsten, tin, etc.). For example, in tin ore tests, the L-type spiral concentrator enriched the raw ore tin grade from Sn 0.4% to 10.2% in a single pass, achieving a 25-fold enrichment ratio, with a recovery rate comparable to that of shaking tables but with less tailings loss. In a scheelite project in Australia, spiral chutes replaced the flotation process, with spiral gravity separation achieving a recovery rate of over 80% for the raw ore (currently, the recovery rate for scheelite flotation with heating is around 78%).

3. High processing capacity and no power requirement

The spiral chute has a simple structure with no moving parts, relying on gravity and water flow for natural separation, eliminating the need for additional power consumption and significantly reducing energy costs. A single unit can process up to 30 mt of ore per hour, making it suitable for large-scale placer ore roughing scenarios.

4. Strong adaptability and low operating costs

The spiral chute exhibits strong adaptability to fluctuations in feed concentration, particle size, and grade, allowing for a wide range of ore concentration variations and reducing the need for pre-treatment. Meanwhile, its nylon/polyurethane material is wear-resistant, corrosion-resistant, and has a long service life, significantly reducing the comprehensive ore beneficiation cost compared to traditional flotation processes.

5. Environmental Protection, Energy Efficiency, and Small Footprint

The equipment uses less water and requires no chemical reagents, meeting environmental protection requirements. Compared to traditional ore beneficiation equipment, the spiral chute has a smaller footprint, making it particularly suitable for mine sites with limited space. Additionally, the multi-stage separation design further optimizes resource utilization.

Spiral Concentrator Models

Issues in Physical Beneficiation of Tin Ores

Common Issues in Mining and Processing Projects for Continental Alluvial Placer Deposits in Deltas and Continental Shelf Seabed Placer Deposits:

Complex Mineral Composition: Minerals such as zircon-ilmenite and cassiterite are closely associated, with significant density differences from gangue tailings, allowing for the use of gravity separation equipment. Which equipment should be used?

Uneven Mineral Particle Size: Heavy minerals smaller than 0.038mm are easily lost, and jigs or centrifuges are ineffective for separation.

Wave fluctuations and oscillations have a destructive effect on the gravity separation performance of spiral concentrators. However, spiral concentrator production platforms equipped with wave stabilization devices can recover ultra-fine heavy minerals (+800 mesh tin ore, +0.019mm).

The rough surface of ordinary land-based spiral concentrators is ineffective for separating ultra-fine particles. How can the friction and roughness of the spiral chute surface be balanced?

Stringent Environmental Regulations: Flotation cannot be used at placer mining and processing sites, and the treatment of chemical wastewater from rock ore grinding and flotation becomes more difficult.

Solution: The above issues can be resolved by using ALICOCO spiral concentrators in conjunction with unique process technologies.

Features of Spiral Concentrators

1. Layered Collection of Concentrates. Each type of our spiral concentrator can be equipped with concentrate collection ports at each turn, allowing for the mid-course interception of concentrates, known as "layered collection of concentrates," achieving the efficiency of "early collection leads to higher yield."

2. Arc-Shaped Guide Dams on the Chute Surface. The spiral chute surface is equipped with a sufficient number of arc-shaped dams that spiral inward from the outer edge to the center, enhancing the concentration of fine-grained heavy minerals.

Spiral concentrators with these two functional features, combined with an increased number of turns in the beneficiation process, have significantly higher separation efficiency than ordinary spiral concentrators and can simplify the complex "re-election" process. Using FG7 spiral roughing and scavenging, supplemented by large-diameter spiral concentrators for cleaning, and further paired with high-intensity magnetic tailings discarding equipment, an efficient yet simplified iron ore beneficiation process can be achieved. This approach may reduce flotation treatment volumes, decrease chemical pollution emissions, alleviate environmental protection pressures, and potentially pre-discard tailings to reduce roasting treatment volumes, achieving substantial energy savings, emission reductions, and cost savings, with excellent results.

From the perspective of the Australian scheelite project, the ALICOCO spiral concentrator of the company can replace the flotation process, achieving a higher beneficiation recovery rate than flotation.

Product advantages: The beneficiation effect is comparable to that of shaking tables (for tin ore).

In summary, the spiral concentrator has significant advantages such as a small footprint, high processing capacity, and high recovery rate. We can adopt new-type advanced equipment to break through the limitations of outdated equipment, thereby simplifying the process flow, reducing production costs, and increasing efficiency.

It showcased product videos, including those of tin-bearing associated ore products, and introduced projects involving tin-bearing alluvial sand-type zircon-titanium-iron ore.

It also presented relevant cases of tin-bearing polymetallic copper ore and chromite, as well as the replacement of flotation with gravity separation for scheelite-associated tin ore.

Coal-fired power plant flue gas desulfurization project

Problems in flue gas desulfurization at power plants: Both wet and dry desulfurization technologies involve desulfurization after coal combustion, requiring significant investment in desulfurization equipment and complex technology.

The company's solution: Grind the coal before combustion, wash it with a spiral concentrator to desulfurize and reduce the coal ash content, thereby increasing the calorific value. The desulfurized pyrite generally has a sulfur content of over 35% sulfur grade, which can be sold to sulfuric acid plants for sulfuric acid production or for sulfur production. The separated ash serves as high-grade raw material for cement plants. This reduces the area required for fly ash storage by 70%. The calorific value of the washed clean coal slurry can increase by 30%.

Conclusion: Pre-combustion desulfurization requires less equipment investment, involves simple technology, has high value in comprehensive utilization, and is easy to promote and popularize.

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