Frac Sand and Silica Sand Processing in the United States and Canada
Proppant, glass sand and foundry sand graded to specification at the deposit, whether the feed is West Texas dune sand or a Northern White or Canadian deposit that needs washing.
CFlo builds modular plants that grade North American silica sand to a tested specification. The Aerograder is the dry route: a water-free minus 200 mesh cut, measured in Abu Dhabi at 280 tonnes an hour across four units, that runs after the dryer ahead of the finishing screens, or in place of part of the wet circuit where a Sample Study shows the deposit allows it. The Micrograder is the wet route for Northern White, Canadian in-basin deposits and any feed that carries clay, silt or coatings, recycling around 95% of its water. Plants for the United States and Canada carry UL-listed control panels for the United States and CSA-certified panels for Canada, and every plant is sized from a Sample Study of the customer's own material before it is engineered.
Two markets, one specification
The United States is the largest proppant market in the world, and more than half of its demand is in the Permian Basin, where in-basin dune sand has displaced most of the Northern White that used to arrive by rail. Canada's Western Canadian Sedimentary Basin uses 8 to 9 million tonnes of frac sand a year, roughly two thirds of it in the Montney, and most of that still travels by rail from Wisconsin, which is why in-basin sand projects in Alberta and British Columbia are being built and permitted. Montney wells are among the most sand-intensive anywhere, at around two tonnes of proppant per meter of lateral.
Whatever the basin, the sand is sold against the same standards. Under API RP 19C and ISO 13503-2, at least 90% of a tested sample must fall between the two designating sieves for its grade, whether 20/40 (841 to 420 micron), 30/50 (595 to 297 micron), 40/70 (420 to 210 micron) or 70/140 (210 to 105 micron, the grade the trade sells as 100 mesh, along with wider blends such as 40/140). Not more than 0.1% of the sample may be retained on the first sieve of the test stack, one size coarser than the top designating sieve, and not more than 1% may reach the pan below the sieve one size finer than the bottom designating sieve: minus 100 mesh for 40/70, minus 200 mesh for 70/140. The same standards set limits on sphericity and roundness, crush resistance, turbidity and acid solubility, and clay, silt and surface coatings have to come off the grain before those limits can be met. The market has moved to finer products, 100 mesh and 40/200 in particular, which moves the bottom cut from 140 mesh to 200 mesh and turns material that used to be rejected into saleable product. That cut is held dry by the Aerograder or wet by hydrocyclones and a hydraulic classifier, depending on the feed, and the fines that do come out are recovered and dewatered rather than left in a pond.
Glass sand and foundry sand are specification products of the same kind, judged on chemistry as well as grading. Two numbers decide what a silica deposit is worth: SiO2, which says how much of it is quartz, and Fe2O3, which says how much iron oxide is left. Commercial soda-lime glass runs at 70 to 74% silicon dioxide, and the float glass specification held at Chu Lai in Vietnam calls for more than 99% SiO2 with Fe2O3 below 0.05%, in a band between 150 and 600 micron. Foundry sand is bought on grading and AFS fineness number, held batch to batch. In every case the engineering problem is the same: a precise top-size and bottom-size cut, residual fines removed below the bottom sieve, and surface contamination stripped, repeatably, at production rate. See also frac sand and proppant, silica and glass sand and foundry sand.
The dry route: the Aerograder in a North American plant
Every in-basin plant in West Texas and New Mexico runs a wet plant, a gas-fired dryer and dry finishing screens, and the 200 mesh cut that decides the 40/200 and 100 mesh products is made on the dry side. That is where the Aerograder sits: a water-free minus 200 mesh stage after the dryer and ahead of the finishing screens, taking the fines off before they reach the decks so the screens run clean and the 1% pan limit holds. Where a Sample Study on the pit sand shows the feed arrives dry and carries little bonded clay, the same machine can take over part of the wet circuit and cut the groundwater a plant draws, but that is a finding on the deposit, not a claim. CFlo deploys the Aerograder air classifier: a fines cut with no process water, no cyclone, no baghouse and no airlock, set by four controls, the selector blades, the feed rate to air ratio, the fan blades and the rejector speed. It cuts cleanly in the 75 to 100 micron region, which is where the residual fines below the finest designating sieves have to be removed.
Three conditions form part of the specification. The feed is below 5 mm, because the machine cuts fines and coarser material belongs on a screen or in a wet plant. Surface moisture is below 2%, because air will not separate damp fines. And the feed is dry all year, which depends on the circuit rather than the season: an enclosed crusher-to-classifier circuit or an arid site gives year-round dry feed, and either arrangement is written into the specification. Only water removes bonded clay, so a feed carrying silt, mud, clay or organics is a wet duty. Two models are available, the Aerograder C100 at 60 to 70 tonnes an hour (about 66 to 77 US tons) and the Aerograder C200 at 120 to 150 tonnes an hour (about 130 to 165 US tons), and capacity scales by running units in parallel rather than by oversizing a single shell.
Abu Dhabi: proppant graded with no process water
The dry route has been measured in the field on the same kind of material. In Abu Dhabi, four Aerograder C100-class units run in parallel, 280 tonnes an hour of combined capacity, grading local dune and silica sand into frac sand for a major oil and gas services operator in a basin where water cannot be spared. Across a July 2026 verification campaign at 70 tonnes an hour per unit, the graded product averaged 0.83% minus 200 mesh against the 1% specification ceiling and stayed within a 0.71% to 0.98% band across all four machines. Mass yield to product was around 90%, recovery of the plus 140 mesh coarse fraction was about 94%, and the demonstrated median cut was a d50 of about 54 micron, roughly the No. 270 sieve, well below the 75 micron specification gate.
The classified product goes to multi-deck dry screens for the 20/40, 40/70 and 70/140 product bands, and because the fines never reach the deck, blinding and recirculation are almost eliminated. The fines stream itself has value in brick-making, cementitious blends and filler markets. The measured results, campaign by campaign, are in the Abu Dhabi case study.
The wet route: the Micrograder
Where the feed carries clay, silt or surface coatings, or needs both a wash and a sharp size cut, the Micrograder is the platform. That covers Northern White deposits, the Canadian in-basin deposits now being developed in Alberta and British Columbia, and any plant that has to make the finer grades alongside the coarser ones. It is a modular wet processing plant configured from proven process modules to match the deposit and the target product.
Atropure attrition cells scrub the coatings off each grain at 80% solids, so the separation stages downstream read the mineral rather than what is stuck to it. Screenmax precision fines screens fix the top of the gradation and dewater on the same deck. Hydrocyclones hold the bottom. The mid-range cut between two saleable fractions, where a screen would blind and a cyclone would scatter, belongs to the Vertimax upward flow classifier (a hydraulic, teeter-bed classifier), which holds it from a PLC setpoint rather than drifting with the feed. Where iron is carried as discrete heavy mineral grains, Spiropure spiral gravity concentrators take them out by density with no reagents. The Hydromax high rate thickener recycles around 95% of the process water, and the Easysettle sludge management system releases water from the tailings at the point of disposal, so a wet frac sand plant can run close to zero liquid discharge and retire the tailings pond.
Models run from the Micrograder BT50 at 50 tonnes an hour (about 55 US tons) to the Micrograder BT100 and F100 at 100 tonnes an hour (about 110 US tons), with standard capacity varying with feed gradation and site conditions, and larger duties are met by running lines in parallel. That makes the Micrograder the plant for regional and gas-basin operations of roughly half a million to one and a half million tons a year, for the first phase of a Canadian in-basin project, or as a fines recovery and debottlenecking module added to an existing wet plant. It is not a replacement for a five million ton Permian wet plant, and the page does not pretend otherwise.
CFlo's scope is the wet plant, the Aerograder stage and the PLC controls. The dryer, dry finishing screens, storage and loadout are by others or by the customer's chosen supplier, integrated with CFlo's PLC at a defined interface, in the same way CFlo does not supply the dry mill on a mineral sands project. Each plant is built to the standards required by its market, with the PLC control panel that CFlo designs, builds and tests in its own works supplied UL listed for the United States and CSA certified for Canada.
Water, and winter
A Permian wet plant draws roughly 60 to 250 gallons of groundwater per ton of sand, a permitted and costly input in a basin that is short of it. In Alberta a sand plant's water is licensed under the Water Act and in British Columbia under the Water Sustainability Act, and in the Peace region short-term approvals have been suspended in drought years. A wet plant that recycles around 95% of its process water and runs with zero liquid discharge changes what a site needs to be licensed for, and a dry stage that uses no process water at all removes the question for that part of the plant.
In Alberta and British Columbia the first design question after water is winter. Canadian wet plants commonly run seasonally, with the dryer fed all year from a wet stockpile, which halves the annual tonnage a line produces and sizes the stockpile, the thickener and the sludge circuit. Whether a plant runs seasonally or is winterised, and what freeze protection the Hydromax and Easysettle circuit carries, is fixed at Pre-Engineering with the site's own engineers. CFlo's operating references are in warm climates, so that scope is engineered for each site rather than copied from a catalog. Which route and which operating pattern a deposit needs is decided by the feed and the site, and the Sample Study reports the water balance and the product against the specification before any steel is cut.
Chu Lai: float glass sand at 99.3% SiO2
The wet route's record is in holding a narrow band on silica. At CFG-Chu Lai Float Glass in Quang Nam Province, Vietnam, two 100 tonne an hour Micrograder lines take a raw ore of about 98.5% SiO2 and roughly 0.5% Fe2O3, a good silica deposit and still not a glass sand, and produce a final product above 99.3% SiO2 with Fe2O3 below 0.05%. That is a tenfold cut in iron on an entirely gravity-based circuit with no chemical reagents, with Hydromax and Easysettle recovering approximately 95% of the water. Product yield is approximately 71%, the plus 600 micron oversize is sold as a construction sand by-product, and the product sits consistently between 150 and 600 micron. The Chu Lai case study sets out the flowsheet and the results. On the same platform, a Micrograder BT100 at Bharuch in India produces 100 tonnes an hour of AFS 50 to 55 foundry sand with zero liquid discharge, and a Micrograder BT50 at Hue in Vietnam grades low-iron silica sand for cristobalite manufacture at 30 to 35 tonnes an hour, recycling 95% of its process water.
The Sample Study comes first
No plant is engineered from a catalog. Sizing starts with a Sample Study at CFlo's own pilot plant and laboratory at Howrah, a DSIR-recognised in-house R&D unit, which runs bench-scale and pilot-scale programs on bulk samples as a connected circuit rather than as jar tests, so the interactions between stages are in the result rather than assumed. The usual path is a review of your existing gradation data first, then a 20 kg (45 lb) bench sample by courier, and a pilot sample of up to 2500 kg (5,500 lb) only if the bench result justifies it. Samples come to the CFlo works at Sankrail Industrial Park, Howrah, India, on a DDP basis with the paperwork agreed first, and how the sample is taken matters as much as how much is sent, so that is the first conversation.
What comes back is a report, not an opinion: feed characterization, stage-by-stage results, a mass balance across the flowsheet, fraction-wise chemical assay of feed and product, product grades and yields against the specification the sand will be sold on, consumption figures for water, polymer and power, a recommended flowsheet sized to the tonnage, and samples of the products to put in front of your own customer. Where a product is sold against an industry standard, the report presents the sieve analysis and product grading in that standard's format, and product samples come back with it for your own API RP 19C laboratory to confirm the crush, turbidity and acid solubility results. Reports are confidential to you.
Pre-Engineering follows only if the numbers work. It runs in parallel with your capital approval: process flow, mass and water balance, a final sized equipment list, plant general arrangement, civil and structural drawings with foundation loading and utility schedules, and long-lead items identified early. Manufacture then starts on placement of the supply contract rather than after a further design loop. The Sample Study and Pre-Engineering page sets out both services in full.
Send us a sample
Tell us about the material and an engineer will come back with how much to send, how to sample it, and what the programme would cover.
Who you deal with in North America
CFlo North America handles sales and support inquiries for the United States and Canada on +1 587 883 2657 or [email protected]. Delivery is managed by CFlo Europe Limited in Belfast, whose territory covers the UK, Europe, North America and Oceania, so the team delivering CFlo's first frac sand plant, a Micrograder in manufacture for a site near Darwin with commissioning scheduled for early 2027, is the team that would deliver yours. The measured wet-route references today are the glass and foundry sand plants at Chu Lai, Bharuch and Hue, and the measured frac sand reference is Abu Dhabi. CFLO is a registered trademark in the United States (Reg. No. 7,630,688), and CFlo holds the granted United States and Canadian patents on the Combo sand washing plant. Plants for North America carry UL-listed control panels for the United States and CSA-certified panels for Canada, ship as containerized modules, and are erected and commissioned on prepared foundations in weeks rather than months. The North America page sets out the full range, the sand washing plant page covers the Combo, and the contact page lists every regional office.
A career spent building wet processing plant for quarries in Britain and Ireland, having previously helped build a global wet processing brand.
What to send us first
A representative sample or a recent gradation of the feed, a chemical analysis if you have one, the moisture as it arrives, the specification the product has to meet, whether a proppant grade, a glass grade or a foundry fineness number, the tons per hour you want to produce, and how much water the site has. If proppant is currently being railed or trucked to your operation, the landed cost per ton is useful too, because it is the number an in-basin plant has to beat. Send it through the form above, or contact CFlo North America, and we will scope the Sample Study with you before you ship anything.
Frequently asked questions
What specification does frac sand have to meet?
Under API RP 19C and ISO 13503-2, at least 90% of the tested sample must fall between the grade's designating sieves, for example 20/40, 40/70 or 70/140, with no more than 0.1% retained on the first sieve of the test stack and no more than 1% in the pan below the sieve one size finer than the bottom designating sieve, plus limits on sphericity, roundness, crush resistance, turbidity and acid solubility. Clay, silt and surface coatings have to be removed to meet the turbidity, crush and acid solubility limits, and that is what decides between a wet and a dry plant.
Where does the Aerograder fit in a Permian plant?
After the dryer and ahead of the dry finishing screens, as a water-free minus 200 mesh stage that keeps the fines off the decks and holds the 1% pan limit. In Abu Dhabi it held the product below the 1% minus 200 mesh ceiling on all four units on local dune sand. It takes feed below 5 mm at below 2% surface moisture, so on the dry side of the plant those conditions are already met. Whether it can also take over part of the wet circuit on a given deposit is a Sample Study finding, not a claim; a feed carrying silt, clay or surface coatings is a wet duty.
When is a wet plant the right choice?
When the deposit carries clay, silt or surface coatings that must be scrubbed off to meet turbidity and crush limits, or when the product needs both a wash and a sharp size cut. That is the usual case for Northern White and for the Canadian in-basin deposits. A wet frac sand plant recycles around 95% of its process water and can run with zero liquid discharge.
Can a CFlo plant make 100 mesh and 40/200?
The move to 100 mesh and 40/200 moves the bottom cut from 140 mesh to 200 mesh. That cut is held dry by the Aerograder, which made it in Abu Dhabi at a d50 of about 54 micron with less than 1% minus 200 mesh in the product, or wet by hydrocyclones and the Vertimax hydraulic classifier from a PLC setpoint, with the fines recovered and dewatered rather than sent to a pond. Which route suits a given deposit, and what yield it gives, is a Sample Study question answered on your own sand.
Will a Micrograder get our deposit to glass grade?
That depends on the mineralogy, particularly how the iron is carried. At Chu Lai a feed of about 98.5% SiO2 with roughly 0.5% Fe2O3 reached above 99.3% SiO2 with iron below 0.05% on a gravity-based circuit. What a North American deposit reaches is a Sample Study question rather than a claim, which is why sizing starts with your own sample.
How much material does a Sample Study need, and how do I send it?
Programs are sized in bulk from 20 kg for a short bench program up to 2500 kg for a full pilot campaign, depending on the stages involved. Samples come to the CFlo works at Sankrail Industrial Park, Howrah, India, on a DDP basis with the paperwork agreed first. How the sample is taken matters as much as how much you send, so it is worth a conversation before you ship anything.
Who supplies and supports a CFlo plant in the United States and Canada?
CFlo North America handles sales and support on +1 587 883 2657 and [email protected], and delivery is managed by CFlo Europe Limited in Belfast. Control panels are supplied UL listed for the United States and CSA certified for Canada, and plants ship in standard containers. The contact page lists every regional office.