Fractionated and Dried Bentonite

Our fractionated and dried bentonite represents the next level of bentonite processing, combining controlled drying with precise particle size separation to produce multiple product grades, each optimized for specific industrial applications. Unlike standard crushed bentonite with its broad 0-5mm particle distribution, our fractionated product is systematically separated into narrow size ranges, allowing customers to select the exact fraction that delivers optimal performance for their process.

Advanced Fractionation Process: Fractionation is the systematic separation of bentonite into distinct particle size groups (fractions), each with uniform characteristics and predictable performance. Our multi-stage processing ensures:

• Primary Drying: Controlled moisture reduction to ≤12% preserving montmorillonite structure
• Precision Crushing: Size reduction to prepare material for fractionation
• Multi-Stage Screening: Series of calibrated sieves separate material into distinct size fractions
• Wet Fractionation (fine grades): Water-based separation for particles <150μm using sedimentation or hydrocyclones
• Quality Verification: Each fraction analyzed for particle size distribution, montmorillonite content, and performance properties

Why Fractionation Matters: Particle size profoundly influences bentonite performance. Larger particles (2-5mm) provide excellent permeability control and slow, sustained swelling for waterproofing applications. Medium fractions (0.5-2mm) offer balanced properties ideal for iron ore pelletizing. Fine fractions (150-500μm) deliver superior binding in foundry sands. Ultrafine particles (<74μm) provide maximum surface area and instant hydration for high-performance drilling fluids. By selecting the appropriate fraction, customers eliminate undersized particles that create excessive dust and oversized particles that reduce binding efficiency.

The Science of Particle Size Effects:

Surface Area and Reactivity: As particle size decreases, surface area increases exponentially. Coarse 2-5mm particles offer 10-20 m²/g surface area, while ultrafine <44μm fractions exceed 100 m²/g. This dramatic increase in reactive surface translates directly to faster swelling, stronger binding, and enhanced adsorption capacity.

Swelling Kinetics: Coarse fractions absorb water slowly (hours), making them ideal for applications requiring gradual, sustained sealing. Fine fractions hydrate rapidly (5-15 minutes), perfect for immediate binding in pelletizing and molding. Ultrafine particles swell almost instantly (<5 minutes), critical for drilling mud activation.

Packing Density and Permeability: Fine particles fill voids between larger particles, creating denser packing and lower permeability—essential for waterproofing. Coarser fractions maintain higher porosity, allowing controlled gas escape in foundry molds while still providing adequate binding strength.

Available Fractions and Applications:

Coarse Fraction (2-5mm)

Characteristics:

• Particle size: 2000-5000 micrometers
• Slow swelling (several hours to full hydration)
• High permeability to gases
• Low dust generation
• Surface area: 10-20 m²/g

Primary Applications:

• Waterproofing Barriers: Foundation excavations, basement walls, underground structures
• Pond and Lagoon Liners: Environmental containment, agricultural water storage
• Well Sealing: Abandoned well closure, groundwater protection zones
• Landfill Caps: Geosynthetic clay liner (GCL) component
• Spill Absorbents: Industrial liquid containment, emergency response

Performance Benefits:

• Gradual swelling prevents rapid pressure buildup
• Self-healing properties seal cracks over time
• Excellent long-term stability in saturated conditions
• Minimal dusting during handling and placement

Medium Fraction (0.5-2mm / 10-35 mesh)

Characteristics:

• Particle size: 500-2000 micrometers
• Moderate swelling rate (30-60 minutes)
• Balanced binding and permeability
• Surface area: 30-50 m²/g
• Optimal for mechanical mixing systems

Primary Applications:

• Iron Ore Pelletizing: Primary binder for concentrate agglomeration (0.8-1.5% addition)
• Drilling Fluids (base component): Initial mud mixing for oil/gas/geothermal drilling
• Soil Stabilization: Road construction, embankment reinforcement
• Construction Slurries: Diaphragm walls, secant pile installation
• Grouting Applications: Void filling, ground consolidation

Performance Benefits:

• Ideal particle size for pelletizing drum/disc distribution
• Creates strong green pellets (>1 kg/pellet compression)
• Excellent dispersion in water-based systems
• Cost-effective balance of performance and price

Fine Fraction (150-500μm / 35-100 mesh)

Characteristics:

• Particle size: 150-500 micrometers
• Fast swelling (5-15 minutes to full hydration)
• High binding capacity
• Surface area: 60-100 m²/g
• Excellent workability in dry-mix formulations

Primary Applications:

• Green Sand Molding (iron casting): 8-10% addition for gray iron, ductile iron
• Ceramic Plasticizers: Improved workability and green strength
• Pellet Binders: Enhanced sphere formation and drop resistance
• Agricultural Carriers: Fertilizer and pesticide delivery systems
• Geosynthetic Clay Liners: Needle-punched GCL manufacturing

Performance Benefits:

• Provides optimal green compressive strength (5-7 psi)
• Balanced gas permeability (100-150 units) for casting applications
• Uniform coating of sand grains in foundry mixtures
• High sand reuse rates (90-95%) with proper conditioning

Very Fine Fraction (74-150μm / 100-200 mesh)

Characteristics:

• Particle size: 74-150 micrometers
• Very fast swelling (5-10 minutes)
• Superior binding strength
• Surface area: 80-120 m²/g
• Enhanced suspension properties

Primary Applications:

• Steel Casting (green sand): 10-12% addition for high-temperature applications
• Drilling Muds (oil & gas): Viscosity control, filtration loss reduction
• Specialty Binders: High-strength industrial adhesives
• Feed Pellet Production: Aquaculture feed, livestock pellets
• Pharmaceutical Excipients: Tablet binding and disintegration control

Performance Benefits:

• Delivers high green strength (>7 psi) for steel casting molds
• Thermal stability maintained to 1400-1500°C
• Excellent rheological control in fluid systems
• Rapid hydration minimizes mixing time and energy

Superfine Fraction (44-74μm / 200-325 mesh)

Characteristics:

• Particle size: 44-74 micrometers
• Instant swelling (<5 minutes)
• Maximum binding efficiency
• Surface area: 100-150 m²/g
• Premium-grade performance

Primary Applications:

• Precision Casting: Investment casting, aerospace components
• API-Grade Drilling Fluids: High-performance oilfield applications
• Cosmetics and Personal Care: Face masks, skin treatments
• Paints and Coatings: Rheology modifier, suspension agent
• Advanced Ceramics: Technical ceramics, electronic substrates

Performance Benefits:

• Meets or exceeds API 13A specifications for drilling fluids
• Minimal filtrate loss (<15 mL API filtration test)
• Superior suspension capacity (yield point >30 lbs/100ft²)
• Ultra-low sand content (<3%) for sensitive applications

Ultrafine Fraction (<44μm / >325 mesh)

Characteristics:

• Particle size: <44 micrometers (submicron to 44μm range)
• Instantaneous swelling (seconds)
• Maximum surface area (>150 m²/g)
• Colloidal properties
• Highest cation exchange capacity

Primary Applications:

• Nanotechnology: Nanocomposite matrices, functional coatings
• Catalyst Supports: Petrochemical processing, environmental catalysis
• High-End Drilling Fluids: Deepwater, HPHT (High Pressure High Temperature) wells
• Pharmaceutical Binders: Advanced drug delivery systems
• Specialty Inks: Flexographic, gravure printing systems

Performance Benefits:

• Maximum swelling capacity (15x+ volume expansion)
• Exceptional rheological control at low concentrations
• Superior adsorption of ions, molecules, and contaminants
• Stable colloidal suspensions for extended periods