Shaking Table Applications in Mineral Processing

Shaking tables are an essential piece of gravity separation equipment widely used in the mineral processing industry. Known for their simplicity, efficiency, and ability to separate minerals based on density differences, shaking tables have been employed for centuries to concentrate valuable minerals from ore. Despite advancements in mineral beneficiation technologies, shaking tables remain relevant due to their high precision in fine particle separation, low operational costs, and adaptability to various minerals. This article explores the diverse applications of shaking tables in mineral processing, highlighting their role in different ore types and processing stages.

Shaking Table Working Principle

Before delving into applications, it is important to briefly revisit the working principle of shaking tables. The device separates particles based on differences in specific gravity by combining the effects of shaking motion, water flow, and riffled deck surface. Heavier particles settle and move differently compared to lighter gangue minerals, enabling effective separation.

Major Applications of Shaking Tables

1. Gold Concentration

One of the most prominent applications of shaking tables is in the concentration of free gold particles. Gold, being a dense and valuable mineral, is often found in placer deposits or liberated in flotation concentrates.

• Placer Gold Recovery: Shaking tables are commonly used to recover coarse and fine gold from alluvial deposits. The table’s ability to stratify particles helps separate gold from lighter sands and gravels.
• Flotation Concentrate Upgrading: After flotation, shaking tables further upgrade gold concentrates by removing lighter gangue minerals, increasing the grade before smelting.
• Advantages: High recovery of fine gold particles down to 0.02 mm and production of clean concentrates with minimal dilution.

2. Tin and Tungsten Ore Processing

Tin (cassiterite) and tungsten (scheelite) ores are typically heavy minerals that require gravity separation.

• Cassiterite Concentration: Shaking tables efficiently separate cassiterite from quartz and other gangue minerals due to its high density (about 7.0 g/cm³).
• Scheelite Recovery: Tungsten concentrates benefit from shaking tables that upgrade scheelite by removing lighter silicates.
• Role in Flowsheets: Often used after gravity concentration steps like spirals or jigs to produce final concentrates.
• Benefits: Improved concentrate grade and recovery with relatively low water and energy consumption.

3. Chromite Beneficiation

Chromite, a key mineral for stainless steel production, is another heavy mineral commonly processed with shaking tables.

• Gravity Separation: Shaking tables separate chromite from serpentine and silicate gangue based on density contrasts.
• Fine Particle Recovery: Effective for particles in the size range of 0.1 to 2 mm, where other gravity devices may be less efficient.
• Industrial Use: Widely used in chromite plants worldwide as a final concentration stage.
• Outcome: Production of high-grade chromite concentrates suitable for smelting.

4. Coal Cleaning

In coal preparation plants, shaking tables are used to separate mineral impurities such as pyrite, shale, and other heavy minerals from coal.

• Improving Coal Quality: By removing heavy impurities, tables enhance the calorific value and reduce sulfur content.
• Fine Coal Treatment: Particularly effective for fine coal fractions where conventional jigging is less efficient.
• Environmental Impact: Cleaner coal reduces emissions and ash content during combustion.
• Economic Benefit: Increased coal market value and compliance with environmental regulations.

5. Rare Earth Mineral Processing

Rare earth elements (REEs) often occur in complex mineral assemblages requiring gravity separation techniques.

• Separation of Heavy REE Minerals: Shaking tables help concentrate heavy REE-bearing minerals such as monazite and xenotime.
• Pre-concentration Step: Used prior to chemical processing to reduce ore volume and improve downstream efficiency.
• Fine Particle Handling: Tables can process fine particles that are challenging for other gravity devices.
• Importance: Supports the growing demand for REEs in electronics, magnets, and renewable energy technologies.

6. Zircon and Other Heavy Mineral Sands

Heavy mineral sands containing zircon, ilmenite, rutile, and other minerals benefit from shaking table concentration.

• Zircon Upgrading: Shaking tables separate dense zircon from lighter silicate sands.
• Complement to Magnetic and Electrostatic Separation: Often used after magnetic separation to improve concentrate quality.
• Fine Particle Recovery: Effective in recovering fine heavy minerals that might be lost in other processes.
• Industrial Relevance: Used extensively in mineral sand processing plants globally.

7. Recycling and Waste Recovery

Beyond natural ores, shaking tables find applications in recycling and waste treatment.

• Metal Recovery from E-waste: Concentration of heavy metals such as gold, silver, and copper from shredded electronic waste.
• Industrial Tailings Reprocessing: Recovery of residual valuable minerals from tailings ponds, improving resource efficiency.
• Scrap Sorting: Separation of metal fragments from plastics and other materials in recycling facilities.
• Sustainability Impact: Supports circular economy initiatives by reclaiming valuable materials.

Advantages and Limitations

Advantages

• High Separation Efficiency: Excellent for close gravity separations
• Flexibility: Ability to handle various feed conditions and products
• Visual Control: Operators can observe and adjust separation in real-time
• Low Energy Requirements: Typically 0.1-0.3 kWh per ton of feed
• Minimal Chemical Usage: Environmentally friendly operation

Limitations

• Capacity Constraints: Limited to relatively low throughput rates
• Floor Space Requirements: Significant area needed for installation
• Operator Skill Requirements: Experienced operators needed for optimal performance
• Fine Particle Limitations: Efficiency decreases below 75 μm

Shaking tables continue to play a vital role in mineral processing due to their effectiveness in gravity separation of valuable minerals. Their wide-ranging applications—from gold and tin to coal and rare earths—demonstrate their versatility and importance in beneficiation circuits. While modern technologies evolve, shaking tables remain a reliable, cost-effective, and environmentally friendly solution for upgrading mineral concentrates and recovering fine particles. Proper understanding and optimization of operational parameters can maximize their benefits across various mineral processing scenarios.