# PTMS Kaolin

> Processed, iron-removed (magnetically purified) kaolin for overseas industrial buyers, supplied by FOSHAN POWTECH TECHNOLOGY COMPANY LIMITED (brand PTMS), a manufacturer of electromagnetic magnetic separators (https://www.powtechina.com/). Free samples available on request. All parameter values on the site are typical reference values; final specifications per customer agreement.

Contact: sales@powtechina.com · WhatsApp +86 13929907491 · Mon–Sat 08:00–18:00 China time
Factory: No. 9, Building 2, Shijin Industrial Park, Keyun North Road, Shishan Town, Nanhai District, Foshan, Guangdong, China
Office: Unit 1207, Tower 1, West Zone, Lvdao Plaza, No. 129 Jihua West Road, Chancheng District, Foshan, Guangdong, China
Price: on request

## Kaolin grades
- [Ceramic Kaolin](https://www.ptmskaolin.com/kaolin/ceramics/): Sanitaryware, tableware, porcelain tiles, electrical porcelain. Typical: Al₂O₃ 34 – 38 %; SiO₂ 45 – 50 %; Fe₂O₃ ≤ 0.8 %; TiO₂ ≤ 0.5 %; K₂O + Na₂O ≤ 2.5 %; CaO + MgO ≤ 0.8 %; Loss on ignition (LOI) 11 – 14 %; Fired whiteness (1250–1300 °C) ≥ 85 %; Particles < 2 µm 40 – 75 %; 325 mesh (45 µm) residue ≤ 0.5 %; Moisture ≤ 2 %
- [Catalyst-Grade Kaolin (FCC)](https://www.ptmskaolin.com/kaolin/catalyst/): FCC catalyst matrix & in-situ crystallised zeolite, catalyst carriers. Typical: Kaolinite content ≥ 85 %; Al₂O₃ 37 – 40 %; SiO₂ 44 – 48 %; Fe₂O₃ ≤ 0.8 %; TiO₂ ≤ 1.5 %; K₂O + Na₂O ≤ 0.5 %; CaO + MgO ≤ 0.5 %; Free quartz ≤ 2 %; Loss on ignition (LOI) 13 – 14.5 %; Particles < 2 µm ≥ 75 %; 325 mesh (45 µm) residue ≤ 0.1 %; Moisture ≤ 1.5 %
- [Paper Kaolin (Filler & Coating)](https://www.ptmskaolin.com/kaolin/paper/): Coating pigment for printing & writing papers and board; paper filler. Typical: ISO brightness (R457) 85 – 92 %; Particles < 2 µm 80 – 98 %; Median particle size D50 0.3 – 1 µm; 325 mesh (45 µm) residue ≤ 0.05 %; Fe₂O₃ ≤ 1 %; TiO₂ ≤ 1 %; Brookfield viscosity (70 % solids, 100 rpm) ≤ 500 mPa·s; pH (slurry) 4.5 – 7.5 –; Moisture (dry product) ≤ 1.5 %
- [Filler Kaolin (Paint, Rubber, Plastics)](https://www.ptmskaolin.com/kaolin/fillers/): Architectural & industrial paints, rubber, cables, plastics, adhesives, inks. Typical: Whiteness (dry powder) 88 – 95 %; Median particle size D50 0.8 – 5 µm; Particles < 2 µm 50 – 90 %; Oil absorption 30 – 65 g/100 g; 325 mesh (45 µm) residue ≤ 0.05 %; Fe₂O₃ ≤ 1 %; pH (10 % slurry) 4.5 – 8 –; Moisture ≤ 1 %; Loss on ignition (hydrous / calcined) ≤ 14 %
- [Fiberglass-Grade Kaolin](https://www.ptmskaolin.com/kaolin/fiberglass/): E-glass & C-glass continuous filament, glass wool, alumina source for glass batch. Typical: Al₂O₃ 36 – 39 %; SiO₂ 44 – 48 %; Fe₂O₃ ≤ 0.4 %; TiO₂ ≤ 0.8 %; K₂O + Na₂O ≤ 0.5 %; CaO + MgO ≤ 0.6 %; Loss on ignition (LOI) 13 – 14.5 %; 325 mesh (45 µm) residue ≤ 5 %; Moisture ≤ 1 %

## Pages
- [Spec Builder / RFQ](https://www.ptmskaolin.com/spec-builder/): choose grade, edit target/min/max, packaging (25 kg bags, 1 t jumbo bags, bulk), quantity, port; send via WhatsApp or email
- [Processing & why PTMS](https://www.ptmskaolin.com/applications/)
- [FAQ](https://www.ptmskaolin.com/faq/)
- [About](https://www.ptmskaolin.com/about/)
- [Contact](https://www.ptmskaolin.com/contact/)

## Technical guides
- [Kaolin purification: from crude clay to an industrial grade](https://www.ptmskaolin.com/guide/kaolin-purification/): Crude kaolin is a mixture of kaolinite with quartz, mica, feldspar and iron- and titanium-bearing minerals. Purification separates these in stages — degritting for coarse minerals, classification for particle size, magnetic separation and bleaching for colouring iron — so that the final product meets whiteness, chemistry and fineness limits.
- [Iron removal from kaolin with an electromagnetic slurry magnetic separator](https://www.ptmskaolin.com/guide/iron-removal-magnetic-separator/): Iron-bearing minerals such as hematite and goethite are only weakly magnetic, so they are removed from kaolin slurry with a high-intensity, high-gradient electromagnetic separator: slurry flows through a magnetised matrix that traps the iron particles, and the matrix is periodically flushed with the field switched off. The result is lower Fe₂O₃ and higher whiteness.
- [Kaolin whiteness and brightness: what the numbers mean](https://www.ptmskaolin.com/guide/kaolin-whiteness-brightness/): ISO brightness is the diffuse blue reflectance of a pressed powder at 457 nm; whiteness values and L*a*b* colour describe the full colour; fired whiteness is measured on a test piece after firing and is what matters for ceramics. Iron and titanium oxides are the main factors that lower all three.
- [Hydrous vs calcined kaolin: how they differ and how to choose](https://www.ptmskaolin.com/guide/hydrous-vs-calcined-kaolin/): Hydrous (washed) kaolin keeps its combined water (loss on ignition about 13–14 %) and is plastic and less abrasive. Calcined kaolin has been heated to drive that water off; it is brighter, more opaque and more oil-absorbent, but harder and non-plastic. Choose by the property your formulation depends on.
- [Kaolin by industry: ceramics, paper, rubber, fiberglass and catalysts](https://www.ptmskaolin.com/guide/kaolin-applications-by-industry/): Ceramics use kaolin for alumina, plasticity and fired whiteness; paper for coating and filling; rubber as a non-black filler; fiberglass as an alumina source; FCC catalysts as matrix and as raw material for in-situ zeolite. Each needs different parameters — fired whiteness and Fe₂O₃, brightness and fineness, grit, stable Al₂O₃/SiO₂, or low alkalis.
- [How to read a kaolin specification sheet](https://www.ptmskaolin.com/guide/kaolin-specification-sheet/): A kaolin specification lists chemistry (Al₂O₃, SiO₂, Fe₂O₃, TiO₂, alkalis), LOI, brightness or whiteness, particle size, 325-mesh residue and, for some uses, viscosity or oil absorption. Every number is only meaningful together with its test method, so state the method, the limit type and the moisture basis in your RFQ.
- [All guides](https://www.ptmskaolin.com/guide/)

## Full content
- [llms-full.txt](https://www.ptmskaolin.com/llms-full.txt): plain-text summary of all pages and specs