The modular nature of our equipment ensures:

• Maximum process efficiency: Careful attention to every transfer point retains material and water within the circuit, maximising saleable proppant yield from each tonne of feed
• Minimal footprint: Integrating several processing phases into compact modular units reduces the area your plant occupies and lowers overall project cost through reduced associated civil works
• Rapid deployment: Our modular range installs in a fraction of the time of a traditional stick-build static plant, so you reach saleable production sooner
• Minimal environmental impact: Our Zero-Liquid Discharge option recycles up to 95% of process water, a decisive advantage for frac sand operations in arid and water-stressed basins. Where water is genuinely unavailable, our dry classification route removes the wet circuit altogether

What defines a frac sand

Frac sand is a proppant. Once pumped into a fractured reservoir it has to hold the fracture open under closure stress while still allowing hydrocarbons to flow. That places tight demands on the processed product:

• Particle size distribution: A minimum of 90% of the tested sample must fall between the two designating sieve sizes for the grade (for example 20/40, 30/50, 40/70, 70/140). Not more than 0.1% may be larger than the coarse designating sieve, and not more than 1% may be finer than the fine designating sieve
• Sphericity and roundness: Premium grades require well-rounded, near-spherical grains so that the proppant pack stays conductive under load
• Crush resistance, turbidity and acid solubility: Clay, silt and surface coatings must be washed out so the product meets turbidity and crush-strength limits under API RP 19C and ISO 13503-2

The recurring engineering challenge is the same one our process labs solve on every job: making a precise top-size and bottom-size cut, then removing the residual fines below the bottom-size sieve, repeatably, at production rate. The reference grade and sieve table below frames the conversation we have with every proppant client.

Route 1: Wet processing

Where the feed carries clay, silt or surface coatings, or where the deposit needs both a sharp size cut and a wash, a wet processing circuit is the proven route. CFlo builds the complete modular design – feed preparation, attrition scrubbing to liberate clay and strip coatings, upward-flow hydraulic classification to lift oversize and undersize away from the in-spec fraction, fine-sand recovery, and high-frequency dewatering screens that can be configured to deliver more than one dewatered product at once. Cyclones and our water treatment range recover ultra-fines from the classifier overflow and return clarified water to the circuit, so a wet frac sand plant can run close to Zero-Liquid Discharge even on a tight water budget.

Typical wet plant equipment from our range:

• Feed system and feed sump
• Attrition scrubbing
• Modular sizing and classification
• Upward-flow hydraulic classification for sharp grade separation
• Fine sand recovery and dewatering
• High-frequency dewatering and sizing screens, configurable for multiple dewatered products
• Cyclones for ultra-fine recovery from classifier overflow
• Water recycling and tailings management
• Stockpiling and, where required, thermal drying

Route 2: Dry classification

Many frac sand deposits, particularly in desert and arid basins, arrive already dry and largely clean. In that case a full wet circuit adds cost, water and footprint that the material does not need. For these feeds CFlo deploys the Aerograder air classifier, which makes a precise fines cut with no water, no cyclone, no baghouse and no airlock. The Aerograder takes feed below 5 mm at 1 to 2% surface moisture and makes a clean cut in the 75 to 100 micron region, exactly the zone where a frac sand operator has to meet the sub-1% bottom-size limit.

The dry route is the right choice when:

• Water is scarce, expensive or not permitted for discharge
• The feed is already dry and free of bonded clay
• The job is fundamentally a precise fines and top-size cut rather than a wash
• Lowest operating cost and smallest footprint are decisive

Field validation:

A frac sand operation in the GCC commissioned a CFlo dry classification line for proppant production. The installed design runs four classifier units in parallel for a combined throughput target. During the validated field test, the units processing the test feed delivered:

• 91.6% saleable product yield
• 94.7% coarse recovery above 106 micron
• 0.94% residual fines, inside the sub-1% frac sand bottom-size limit (PASS)
• Cut performance of d50 = 43 micron and d25 = 101 micron

This result was achieved with no process water, in a basin where water cannot be spared, and is now the calibration reference for our frac sand process modelling.

Recommended Frac Sand Sizes (reference grade and test sieve nest)

Recommended sand size rule

A minimum of 90% of the tested sand sample should fall between the designating sieve sizes (that is 6/12, 12/20, 20/40, and so on). Not over 0.1% of the total tested sample should be larger than the first (coarse) sieve size, and not over 1% should be smaller than the last (fine) sieve size.