Spray drying tower inside the Censil Silica production plant
Every parameter logged, every batch repeatable

Six stages where nothing is left to drift

We treat manufacturing as an extension of application engineering. The recipe behind your validated sample — reaction curve, wash endpoint, tower temperatures, classifier settings — is frozen into the production record, and each of the six stages below runs against it. That is how a repeat order arrives behaving like the first.

6stages under parameter control
100%of batches tested before release
COAattached to every shipment
From recipe to repeat order

What each stage is asked to hold

Precipitated silica is a manufactured structure: change one condition during synthesis and the material changes with it. Our answer is procedural — fix the parameters per grade, log them per batch, and let six stages carry your sample's structure into every repeat order.

Stainless-steel reactors in the precipitation workshop
Stage 01

Reaction & Precipitation

This is the stage that decides what the material is. Acid meets silicate under a grade-specific recipe — feed rate, concentration, temperature curve — and the porous network grows to a defined surface area and structure level. A high-structure carrier, a thickener and a gentle cleaning silica part ways here, long before any drying or milling.

  • pH and temperature traced across the full reaction
  • Surface area and porosity fixed by recipe, not corrected later
  • One recipe file per grade, reused batch after batch
Filter presses washing and dewatering silica slurry
Stage 02

Filtration & Washing

Filter presses squeeze the slurry into cake while wash water carries away the sodium sulfate the reaction left behind. We don't count wash cycles — we measure them: filtrate conductivity must fall below the grade's endpoint before the cake moves on, because salt that survives washing reappears later as purity and pH drift.

  • Washing run to a conductivity endpoint (Na₂SO₄)
  • Cake inspected and released before it enters drying
  • Endpoint set per grade, verified per batch
Spray drying tower turning silica slurry into powder
Stage 03

Spray Drying

Redispersed cake is atomized into a hot tower, and the inlet/outlet temperature pair becomes the control knob for moisture, bulk density and particle build. Hold that pair steady and a free-flowing carrier stays free-flowing; let it wander and yesterday's grade becomes a different powder. Tower settings therefore live inside the locked batch record.

  • Inlet/outlet pair held per grade recipe
  • Moisture verified under the 6% ceiling
  • Bulk density checked against the sample baseline
Milling and air-classification line for silica powder
Stage 04

Milling & Classification

Chemistry is settled by now; particle size is not. The dried product runs through mills and air classifiers set to each grade's D50 window, with the 45 µm sieve residue capped as a second guardrail. A fine cosmetic powder and a coarse feed carrier can share a reactor recipe — they are separated here, by classifier settings alone.

  • Classifier settings define the D50 window
  • 45 µm oversize capped per grade
  • Particle size measured in-line during the run
Batch testing bench in the silica quality control laboratory
Stage 05

Quality Control

No batch leaves without numbers. The lab measures BET surface area, DBP oil absorption, laser-diffraction particle size, pH, moisture, ignition loss and SiO₂ content, then compares each figure to the specification your sample was validated against. The COA that travels with the goods is that comparison in writing — and a retained sample stays with us in case a question comes back.

  • Seven properties checked against the validated spec
  • Every COA tied to a batch number and shipment
  • Retained samples archived for later reference
Packaging line and palletized silica ready for export
Stage 06

Packaging & Warehousing

Passing batches go into PE-lined 20/25 kg kraft bags or 500 kg / 1,000 kg big bags (FIBCs), palletized, stretch-wrapped and labelled by batch so traceability survives the voyage. Because several grades can share one container, a customer can trial three materials on a single bill of lading — then reorder only the ones that earned their place.

  • Lined kraft bags or FIBCs, matched to your handling setup
  • Batch number printed on every bag and pallet
  • Mixed-grade containers for low-risk first orders
Why we obsess over parameters

Consistency is the product

Validated once, held forever

Your validation work is an investment. We protect it by freezing the sample's production parameters into the grade recipe, so the surface area, particle size and absorption your lab approved reappear at tonne scale.

Six tracks, one discipline

Feed carriers, food flow aids, dental silica, agro carriers, refining adsorbents and cosmetic powders all run down this same route — what separates them is which parameters each recipe fixes at precipitation and classification.

Packed for the long haul

PE liners keep moisture out, batch labels keep traceability in, and mixed-grade containers keep first orders small. Scaling from a 25 kg trial to full-container repeats changes the quantity, never the material.

Need the process documentation behind your grade?We can send TDS files, sample COAs, packaging drawings and lead-time estimates for your target grades and port.
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