Coal Washing Slurry Pump Solutions

Longteng provides pump solutions for coal slurry transfer, classification, dense-medium circuits, fine-coal processing, sump handling, thickener underflow and tailings transportation. Pump configuration and materials are selected according to particle size, solids concentration, slurry density, required flow and head, pipeline conditions and installation arrangement.

Coal washing, also known as coal preparation, separates saleable coal from rock, clay and other unwanted materials. Water is used throughout the plant to support screening, classification, separation and fine-particle recovery, creating different slurry streams that must be transferred between process equipment.

Pumping conditions vary across the preparation plant. Feed and coarse-particle duties may involve larger abrasive solids, dense-medium circuits may require stable pressure, and fine-coal or thickener duties may contain smaller particles at higher concentrations. Sumps introduce additional challenges caused by fluctuating liquid levels and settled material.

Each duty should therefore be evaluated according to its actual process conditions rather than treated as a general coal slurry application.

Pump Applications in Coal Preparation Plants

The process stage determines the required hydraulic performance, solids-handling capability, construction and wet-end material.

Coal Slurry Transportation

Coal slurry must be transferred between screens, tanks, separation equipment and downstream treatment stages. Particle size and concentration can change as the material moves through the plant.

Typical duties include:

• Raw coal slurry transfer
• Process feed transportation
• Slurry circulation
• Intermediate process transfer
• Transfer between tanks and equipment
• High-concentration slurry handling

The required pump should be selected according to normal and maximum flow, total dynamic head, particle size, solids concentration and expected operating range.

Coarse or abrasive feed slurry may require heavy-duty construction with replaceable wet-end components. For demanding duties, the Mining Slurry Pump – SH can be configured according to the actual hydraulic and wear conditions.

Classification and Screening Circuits

Coal preparation plants use screens, classifiers and hydrocyclones to separate material according to particle size and density. Slurry may need to be transferred continuously between classification stages.

Applications can include:

• Screen feed
• Classification circuit transfer
• Hydrocyclone feed
• Undersize slurry handling
• Process recirculation
• Transfer to separation equipment

Hydrocyclone performance depends on maintaining the required feed flow and pressure. The hydraulic review should include discharge pressure, pipeline resistance, slurry density and operating range.

Where the circuit requires higher head or stable pressure, the High Head Mining Slurry Pump – SHH may be evaluated against the complete system curve.

Dense-Medium Separation

Dense-medium separation uses a suspension with controlled density to separate coal from heavier unwanted material. Where this process is used, pumps may handle feed, circulation or medium-recovery duties.

Typical duties can include:

• Dense-medium cyclone feed
• Medium circulation
• Correct medium transfer
• Dilute medium transfer
• Recovery circuit circulation
• Transfer between medium tanks and separation equipment

The presence of fine magnetite or other dense-medium solids can increase slurry density and contribute to wear. Maintaining stable flow and pressure is also important for consistent separation.

Pump selection should account for:

• Medium density
• Solids concentration
• Required cyclone pressure
• Particle size
• Pipeline resistance
• Pump speed
• Motor power

The material and hydraulic configuration should be confirmed for the actual medium and operating conditions.

Fine-Coal and Slimes Handling

Fine-coal circuits handle smaller particles separated from the main process stream. Depending on the plant design, these duties may include flotation, fine-coal recovery, thickening or slurry circulation.

Applications can include:

• Fine-coal slurry transfer
• Slimes handling
• Flotation feed and transfer
• Fine-particle recovery circuits
• Thickener feed
• Intermediate process circulation

Although particle size may be smaller, fine slurry can still cause wear and may operate at elevated solids concentration. Settling behavior, viscosity and chemical conditions should also be considered where relevant.

The Mineral Processing Slurry Pump – SM is intended for medium-duty process transfer where stable hydraulic performance and replaceable wet-end components are required.

For fine-particle duties where elastomer protection is suitable, the Rubber Lined Slurry Pump – SHR may also be considered. Rubber should not be selected automatically for large, sharp or highly abrasive particles; material suitability must be confirmed from the actual slurry.

Sump and Collection Tank Pumping

Water, slurry leakage, washdown material and settled solids can collect in sumps and pits throughout a coal preparation plant.

Typical duties include:

• Plant sump pumping
• Process spillage recovery
• Slurry collection
• Floor drainage
• Washdown water handling
• Return slurry transfer

Vertical Slurry Pumps can be used where the wet end operates in the sump while the drive remains above the liquid level.

Selection should account for sump depth, liquid-level variation, solids settling, maximum particle size, required head and available installation space.

Thickener Underflow and Waste Slurry

Fine waste material and process water may be directed to thickeners before water recovery or further handling. Thickener underflow can have a higher solids concentration than the feed stream and may require different hydraulic considerations.

Applications may include:

• Thickener feed
• Thickener underflow
• Waste slurry transfer
• Concentrated fine-particle slurry
• Transfer to dewatering equipment
• Slurry recirculation

Higher solids concentration can affect pipeline friction, power demand and the acceptable operating range. The pump should be selected using the expected minimum, normal and maximum concentration.

Coal Washing Tailings Transportation

Residual slurry and rejected material may need to be transported to treatment, storage, dewatering or disposal facilities.

Typical duties include:

• Coal washing tailings transfer
• Reject slurry transportation
• Thickened waste slurry handling
• Tailings pipeline transfer
• Transfer to settling or storage facilities

Tailings pumping requirements depend on concentration, particle size, pipeline length, elevation and the disposal arrangement.

More detailed information about this duty is provided on the Tailings Slurry Pump Solutions page.

Matching Pump Configurations to Coal Preparation Duties

Different process stages require different hydraulic and mechanical characteristics.

This table provides an initial application reference. Final selection requires actual process, slurry and hydraulic data.

Main Pumping Challenges in Coal Washing

Variable Particle Size

Coal preparation plants can handle coarse particles, fine coal, clay and other mineral solids. Particle size can differ significantly between feed, classification, fines and waste circuits.

Maximum particle size affects:

• Solids passage
• Impeller selection
• Pump size
• Operating speed
• Risk of blockage
• Wear pattern

The supplier should receive both the typical and maximum particle sizes. Additional guidance is available in How Particle Size Affects Slurry Pump Selection.

Abrasive Wear

Coal itself may not be the only source of wear. Rock, clay, shale, magnetite and other mineral solids can increase abrasion within the pump.

Wear rate is influenced by:

• Particle hardness and shape
• Solids concentration
• Slurry velocity
• Pump speed
• Wet-end material
• Distance from the preferred operating range

High-chrome alloy may be considered for hard abrasive solids. Rubber may be suitable for finer particles where impact and cutting conditions remain within acceptable limits.

Solids Settling

If slurry velocity becomes too low, solids may settle in suction lines, discharge pipelines, sumps or tanks. Settling can restrict flow, increase blockage risk and make restarting more difficult.

The system should be evaluated for:

• Minimum transport velocity
• Pipe diameter
• Slurry concentration
• Particle size
• Shutdown and restart conditions
• Flushing requirements

Increasing velocity excessively is not an ideal solution because higher velocity can increase friction loss and component wear.

Changing Slurry Concentration

Process conditions and water balance can cause solids concentration and density to vary during operation.

The pump should be reviewed at:

• Normal operating conditions
• Minimum expected flow
• Maximum expected flow
• Different slurry concentrations
• Maximum system head
• Startup and upset conditions

Selecting only for one theoretical duty point may result in unstable or inefficient operation during actual production.

Maintenance and Parts Planning

Continuous coal preparation duties require practical access to wear components and planned maintenance.

Important considerations include:

• Replaceable wet-end components
• Access for inspection
• Impeller and liner adjustment
• Seal configuration
• Bearing arrangement
• Expected wear pattern
• Compatibility with existing equipment
• Availability of replacement components

Longteng supplies slurry pump parts, including impellers, volute liners, frame plate liners, throat bushes, expellers and other wet-end components.

Information Required for Pump Selection

Complete operating information helps determine the appropriate hydraulic model, construction, material, seal and motor requirements.

Process Information

• Coal preparation stage
• Function of the pump
• Source and destination of the slurry
• Continuous or intermittent operation
• Expected operating hours
• Existing pump model, if applicable

Hydraulic Data

• Normal, minimum and maximum flow
• Required total dynamic head
• Required discharge pressure
• Static elevation difference
• Suction conditions
• Pipeline length and internal diameter
• Bends, valves and fittings

Slurry Data

• Type of coal slurry or process medium
• Solids concentration
• Slurry density or specific gravity
• Maximum and typical particle size
• Particle hardness and shape
• Temperature
• pH and relevant chemical components

Installation Data

• Horizontal or vertical arrangement
• Sump or tank dimensions
• Available installation space
• Motor power and available speed
• Electrical supply
• Seal-water availability
• Preferred sealing arrangement
• Required wet-end material

Longteng Support for Coal Preparation Plants

Longteng supports coal washing and preparation duties with pump selection assistance, manufacturing, material configuration and replacement parts supply.

Available support includes:

• Review of process and slurry data
• Hydraulic model selection
• Heavy-duty, high-head and medium-duty configurations
• Horizontal and vertical arrangements
• Metal and rubber material options
• Seal and drive configuration
• OEM manufacturing
• Replacement wet-end components
• Dimensional and compatibility review
• Assembly and performance inspection
• Technical documentation
• Commercial quotation support

The recommended configuration is based on the actual process stage and complete hydraulic duty. This helps reduce the risk of blockage, insufficient pressure, rapid wear, unstable flow or unnecessary power consumption.

Request a Coal Preparation Pump Recommendation

For an initial technical and commercial proposal, provide:

• Process stage or application
• Required flow and total head
• Slurry density and solids concentration
• Maximum particle size
• Pipeline length and elevation
• Required discharge pressure
• Sump or installation arrangement
• Existing pump model, if replacing equipment
• Preferred or existing wet-end material

You can contact our engineering team to discuss pump configuration, material selection, sealing arrangement, drive requirements and replacement-parts scope.

Frequently Asked Questions

What type of pump is used in a coal washing plant?

👉Heavy-duty horizontal pumps are commonly considered for coarse coal slurry and process feed. High-head configurations may be required for hydrocyclone or dense-medium feed, while vertical pumps are frequently used in sumps and collection pits.

What is a coal washing slurry pump?

👉It is a pump used to transport mixtures of water, coal particles and other mineral solids generated during coal preparation. The suitable configuration depends on the specific process stage and operating conditions.

Can these pumps handle abrasive coal slurry?

👉Yes, when the construction and wet-end materials are selected for the actual particle size, hardness, concentration and operating conditions. Rock, shale and dense-medium solids may contribute significantly to wear.

When is a rubber-lined configuration suitable?

👉Rubber-lined pumps may suit fine-particle slurry where the particle shape, impact conditions, temperature and chemistry are compatible with the elastomer. They are not automatically suitable for large or sharp solids.

What information is required for selection?

👉Provide the process stage, required flow and head, slurry density, solids concentration, particle size, pipeline conditions, installation arrangement and material requirements.