Quality control
Buyers rarely complain about the first container. They complain about the fourth, when the whiteness has drifted or the D97 has opened up. Consistency is a process discipline — this is how we run it.
Our eight-step quality chain
Quarry selection
Ore is taken from faces with known geology. Talc, calcite and dolomite from different seams are kept separate rather than blended into an average feedstock.
Raw material grading
Stone is screened and classified by size and quality. Low-whiteness or heavily stained material is segregated now — contamination introduced at crushing cannot be removed later.
Excavator breaking
Bulk material is reduced to crusher feed size, with a second opportunity to reject off-spec stone.
Jaw crusher reduction
Secondary coarse crushing produces a uniform grain. Uneven feed is a main cause of a widening particle size distribution.
Grinding
Six processing units — two 5R Raymond mills, 90 and 110 vertical mills, a ring-roller mill and a pneumatic mill capable of 4000 mesh — selected by target distribution, not just target mesh.
Classification & sampling
Air classification sets the top cut. A sample is tested every ten minutes during production so the classifier is corrected before bagging, not after.
Packaging control
Weight deviation is checked hourly on the packing line and quantity verified against 5 × 8 pallet configurations. Every bag carries product, factory, model and batch.
Third-party testing
SGS or equivalent inspection of chemistry, particle size distribution, whiteness and moisture can be arranged before shipment.
Enterprise standards and downloadable TDS
Every product line is governed by a written enterprise standard that references the relevant GB/T national standards.
| Standard No. | Product | Key requirements | TDS |
|---|---|---|---|
| TDHX-TALC-2023-07 | Talc Powder | SiO₂ 20–65 · Moisture ≤1% · Whiteness 70–97 · D50 2.9–10 µm | |
| TDHX-CC-2023-07 | Calcium Carbonate Powder | CaCO₃ 88–98% · Moisture ≤1% · Whiteness 75–97 · D50 2.9–7.5 µm | |
| TDHX-Dolomite-2025-08 | Dolomite | CaO 27–35% · MgO 22–30% · SiO₂ ≤8% · Whiteness 80–95 |
Testing methods
Chemical composition
Titration and ignition methods quantify the main elements and impurity levels.
Particle size
Laser particle size analyser confirms the D50 and D97 against specification.
Moisture
A moisture analyser determines water content on every sample.
Specific gravity
Gas pycnometer or density bottle measurement.
Want to see the data?
Request a batch certificate or a free sample and run your own bench test before you commit.