Are you struggling with inefficient mineral separation, leaving valuable materials behind? Are you experiencing low recovery rates and high operating costs? This comprehensive guide will give all the details about shaking tables.

Shaking tables are gravity separation devices that separate minerals based on differences in their specific gravity. They are widely used in mineral processing for concentrating valuable minerals and have a very high efficiency.

Let’s move forward and take a deep look!

What is a Shaking Table and How Does it Work?

Are you facing challenges in separating minerals with subtle density differ

ences? Is your current separation process failing to achieve the desired purity levels? Let’s figure out what a shaking table exactly is.

A shaking table, also known as a concentrating table, is a gravity separation device that uses the combined action of a shaking deck, a film of flowing water, and differences in specific gravity to separate minerals.

A shaking table consists of a slightly inclined rectangular deck with a series of riffles (small, raised bars) running parallel to the length of the deck. The deck is mounted on a support mechanism that imparts a rapid, asymmetrical shaking motion.

The working principle can be broken down into these key steps:

1. Feed Presentation: A slurry of finely ground minerals and water is fed onto the deck at the feed box.
2. Stratification: As the deck shakes, the heavier mineral particles settle down and are trapped between the riffles, while the lighter particles are carried by the flowing water over the riffles. This forms distinct layers, or strata, of minerals based on their specific gravity.
3. Differential Motion: The shaking motion is asymmetrical, meaning it has a slow forward stroke and a rapid backward stroke. This differential motion causes the settled particles to “walk” along the deck, with the heavier particles moving slower and the lighter particles moving faster.
4. Separation and Collection: Due to the combined effects of stratification and differential motion, the minerals are fanned out across the deck, with the heaviest minerals concentrated near the top end and the lightest minerals washed away at the tailings end. Splitters or collection launders are used to separate the different mineral fractions.

Industry Insider Tip: The “Lost Art” of Deck Tuning: Most manufacturers provide a standard shaking table setup. However, true optimization requires “tuning” the deck to the specific ore characteristics. This isn’t just about speed and stroke length (which are basic adjustments). It’s about subtly adjusting the riffle configuration and even the deck material itself. 90% of operators never touch these settings after the initial installation, leaving significant recovery on the table (literally!). This is a lost art, often requiring painstaking experimentation, but the payoff is huge.

What are the Types of Shaking Tables and Their Features?

Wondering about the different types of shaking tab

les available? Confused about which one is best suited for your specific application? Let’s check out the different types.

There are several types of shaking tables, generally categorized by their deck design and application. Common types include Wilfley tables, Gemini tables, and Deister tables, each having specific riffle patterns and operating characteristics.

Here’s a breakdown of the common types:

1. Wilfley Table: This is a classic and widely used design. It features a deck with diagonal riffles that are higher at the feed end and gradually decrease in height towards the discharge end.
   • Features: Known for its versatility and ability to handle a wide range of particle sizes.
2. Gemini Table: Primarily used for fine gold recovery. It has a deck with a distinctive “herringbone” riffle pattern.
   • Features: Excellent for recovering very fine particles, particularly precious metals.
3. Deister Table: This design features a deck with a series of “pools” and riffles.
   • Features: Often used for coal cleaning and other applications requiring sharp separations.
4. Multi-Deck Tables: Tables with multiple decks stacked vertically.
   • Features: Increases throughput while taking advantage of a limited area.

Industry Pain Point: The Water Balance Delusion: Everyone talks about water flow rate, but few understand the critical importance of even water distribution. A common mistake is assuming that a high flow rate automatically means better separation. The secret? Use a distributor with multiple, adjustable outlets, and spend hours (yes, hours) meticulously adjusting each one to ensure a perfectly uniform sheet of water across the entire deck surface.

What Minerals are Shaking Tables Primarily Used For?

Struggling to separate specific minerals using other methods? Wondering if a shaking table could be the solution for your particular ore? Let’s see the target material!

Shaking tables are particularly effective for separating minerals with significant differences in specific gravity. They are commonly used for concentrating gold, tin, tungsten, tantalum, and other heavy minerals.

Here’s a more detailed look:

1. Gold: Shaking tables are a cornerstone of gravity gold recovery, particularly for separating fine gold from placer deposits or crushed hard rock ores.
2. Tin (Cassiterite): Cassiterite is a dense mineral that is readily separated from lighter gangue minerals using shaking tables.
3. Tungsten (Wolframite, Scheelite): Tungsten minerals are also dense and respond well to gravity separation on shaking tables.
4. Tantalum and Niobium (Columbite-Tantalite): These minerals often occur together and can be effectively separated using shaking tables.
5. Other Heavy Minerals: Shaking tables can also be used for separating other heavy minerals like chromite, ilmenite, zircon, and garnet.

The advantages in these areas stem from the principle of gravity separation:

• High Specific Gravity Difference: The greater the difference in specific gravity between the valuable mineral and the gangue (waste) minerals, the more effective the separation on a shaking table.
• Fine Particle Size: Shaking tables are particularly effective for separating fine particles (typically in the range of 0.074mm to 2mm) that are difficult to separate using other methods like flotation.
• Liberation: The minerals must be adequately liberated (freed from each other) through crushing and grinding for effective separation on a shaking table.

Unique Perspective: Challenging the “Feed Consistency” Myth: Conventional wisdom says a perfectly consistent feed (in terms of particle size distribution and solids concentration) is essential. While consistency is helpful, I’ve found that a slightly fluctuating feed can sometimes improve separation, particularly with complex ores. Slight variations in density or particle size can create micro-disturbances that help break up this packing and liberate locked particles. This is counterintuitive, but I’ve seen it work in practice.

How to Choose the Right Shaking Table for Your Needs?

Overwhelmed by the various shaking table options available? Unsure about the key specifications and features to consider? Check these selection factors.

Choosing the right shaking table involves careful consideration of several factors, including the type of ore, particle size range, desired throughput, and available space.

%Shaking table selection criteria

Here are the key factors to consider:

1. Ore Characteristics:
   • Specific Gravity Difference: The greater the difference, the easier the separation.
   • Particle Size Range: Different table designs are better suited for different size ranges.
   • Mineral Liberation: Ensure the ore is sufficiently ground to liberate the valuable minerals.
2. Capacity/Throughput:
   • Determine the required tons per hour (TPH) of feed material.
   • Select a table with sufficient deck area to handle the desired throughput.
3. Deck Design:
   • Choose a riffle pattern suitable for your specific ore and particle size range (e.g., diagonal riffles for general use, herringbone riffles for fine gold).
4. Space Availability:
   • Consider the footprint of the shaking table and ensure sufficient space for installation, operation, and maintenance.
5. Budget:
   • Shaking tables range in price depending on size, features, and manufacturer.
   • Balance cost with performance and long-term value.

Specific Application Scenario: The “Black Sand” Nightmare (and Solution): Many operations struggle with heavy black sands (magnetite, ilmenite) overwhelming the shaking table and burying the finer, valuable minerals. A common misuse is to simply increase the tilt of the deck to wash away the black sands. This is a mistake! The solution? A two-stage approach: Pre-Concentration and Deck Modification.

How to Install, Commission, and Operate a Shaking Table?

Concerned about the proper installation and setup of your shaking table? Unsure about the correct operating procedures to maximize performance? Here is the operation instruction.

Proper installation, commissioning, and operation are crucial for achieving optimal performance from a shaking table. This involves careful leveling, adjusting water flow, setting the stroke length and frequency, and monitoring the separation process.

Here’s a step-by-step guide:

1. Installation:
   • Foundation: Ensure a solid, level foundation to minimize vibration.
   • Leveling: Carefully level the table in both the longitudinal and transverse directions.
   • Water Connection: Connect the water supply and ensure even distribution across the deck.
   • Feed Box: Install the feed box and ensure proper slurry delivery.
2. Commissioning:
   • Initial Adjustments: Set the stroke length, frequency, and deck tilt to initial settings based on the manufacturer’s recommendations and ore characteristics.
   • Water Flow Adjustment: Gradually increase the water flow and adjust the distribution to achieve a uniform, thin film across the deck.
   • Test Run: Run a test sample of ore and observe the separation pattern.
3. Operation:
   • Feed Rate Control: Maintain a consistent feed rate and solids concentration.
   • Monitoring: Regularly monitor the separation pattern and adjust the operating parameters as needed.
   • Splitter Adjustment: Adjust the splitters to collect the desired mineral fractions.
   • Regular Inspection: Inspect the deck for wear, the riffles for damage, and the drive mechanism for proper lubrication.

Technical Detail: The “Why” Behind Stroke Length and Frequency: The key is the acceleration imparted to the particles. Higher frequency with a shorter stroke is generally best for fine particles. Lower frequency with a longer stroke is better for coarser particles. The ideal combination depends on the specific gravity difference between the valuable minerals and the gangue. This is why testing with your specific ore is crucial.

What are the Key Points for Shaking Table Maintenance and Longevity?

Worried about the maintenance requirements of a shaking table? Want to ensure a long and productive lifespan for your equipment? Learn about the maintenance.

Regular maintenance is essential for maintaining the performance and extending the life of a shaking table. Key maintenance points include deck inspection, riffle repair, lubrication of moving parts, and regular cleaning.

%Shaking table maintenance

Here’s a detailed maintenance checklist:

1. Deck Inspection:
   • Regularly inspect the deck surface for wear, grooves, or damage.
   • Pay particular attention to the riffles, as worn or damaged riffles will significantly reduce separation efficiency.
2. Riffle Repair/Replacement:
   • Repair or replace worn or damaged riffles promptly.
   • Consider using wear-resistant materials for riffles in high-wear applications.
3. Lubrication:
   • Lubricate all moving parts according to the manufacturer’s recommendations.
   • Use the correct type and grade of lubricant.
4. Cleaning:
   • Regularly clean the deck surface to remove any scale buildup or accumulated material.
   • Use appropriate cleaning agents that will not damage the deck material.
5. Drive Mechanism Maintenance:
   • Inspect the drive mechanism for loose bolts, worn bearings, or other signs of wear.
   • Address any issues promptly to prevent major failures.

Long-Term Performance: The Deck is a Consumable (and its Material Matters): Shaking table decks wear out. Many operators treat the deck as a permanent fixture, neglecting to inspect it regularly for wear and tear. Consider the deck a consumable item, and budget for regular replacement. Furthermore, the deck material significantly impacts longevity. For highly abrasive ores, consider using a polyurethane deck instead of rubber.

What are the Common Shaking Table Faults and How to Troubleshoot Them?

Experiencing problems with your shaking table’s performance? Not sure how to diagnose and fix the issues? Let’s discuss common problems.

Common shaking table faults include poor separation, excessive vibration, uneven water distribution, and mechanical issues. Troubleshooting involves identifying the root cause and taking corrective action.

Here’s a troubleshooting guide:

1. Poor Separation:
   • Possible Causes: Incorrect operating parameters (stroke, frequency, tilt, water flow), worn or damaged riffles, uneven water distribution, incorrect feed preparation.
   • Solutions: Adjust operating parameters, repair/replace riffles, ensure even water distribution, improve feed preparation.
2. Excessive Vibration:
   • Possible Causes: Unbalanced drive mechanism, loose bolts, worn bearings, improper foundation.
   • Solutions: Balance the drive mechanism, tighten loose bolts, replace worn bearings, reinforce the foundation.
3. Uneven Water Distribution:
   • Possible Causes: Blocked or damaged water distributors, incorrect water pressure, unleveled table.
   • Solutions: Clean or replace water distributors, adjust water pressure, re-level the table.
4. Mechanical Issues:
   • Possible Causes: Worn bearings, broken drive components, loose connections.
   • Solutions: Replace worn parts, repair or replace broken components, tighten loose connections.
5. Low Recovery Rate

• Possible Causes: Too much wash water or incorrect table tilt Angle.
• Solution: Adjust water input or tilt angle.

6. Concentrate Grade Too Low

• Possible Causes: Not enough wash water, not enough tilt angle.
  • Solution: Adjust water and tilt angle.

Cost Consideration: Don’t Skimp on the Feed Preparation: The shaking table itself is a relatively small part of the overall plant cost. However, skimping on the feed preparation equipment (crushing, screening, classification) is a HUGE mistake that will dramatically impact the table’s performance and, consequently, your overall recovery and profitability.

Conclusion

Shaking tables are essential for efficient mineral separation, offering high recovery rates and precise control. By understanding their operation, maintenance, and troubleshooting, you can optimize your mineral processing and maximize profitability. Contact ZONEDING MACHINE today for expert advice.