Nepheline Syenite


Nepheline syenite has three main areas of application;

- Ceramics
- Functional fillers
- Glass production

It is a naturally occurring, silica-free, anhydrous sodium-potassium alumina silicate, that delivers improved product performance and is accordant with modern environmental and industrial hygiene standards.

Nepheline syenite is a composed of three primary minerals: the albite form (sodium) of feldspar, the microcline form (potassium) of feldspar and nepheline (feldspathoid).

The existence of nepheline and the absence of crystalline silica is what sets this uniquely occurring rock apart from feldspar fillers, which contain just albite and microcline.

Like feldspar, it provides alkalis that act as a flux in the manufacture of glass and ceramics. In glass production, alumina acts as a matrix of stabilizer, enhancing the workability of molten glass, and increasing the resistance for scratching, breaking and chemical protection.

Filler Grade


In filler applications, nepheline syenite primarily serves as a performance enhancer and has the following functions/advantages:

‣ improves weatherability
‣ improves abrasion, scrub, stain, mildew and
chalking resistance
‣ high brightness (> 92)
‣ great UV protection to resin and pigment system, and high yellowing resistance
‣ low tint strength even at high loading that maximizes the color strength
‣ optimal refractive index allows for high loading in transparent and translucent coatings and stains
‣ good dispersibility and low oil absorption in both water and solvent systems, and low viscosity even in high filler/pigment loading
‣ stable pH and chemical inertness
‣ low vehicle demand and exceptional resistance to
frosting

Specification


Typical Properties

APNS 3APNS 4APNS 5APNS 7APNS 10APNS 12
75µm100%100%100%100%100%100%
45µm99.9%100%100%100%100%100%
30µm98%99.9%100%100%100%100%
20µm75.0%90.0%93.0%99.0%99.5%100%
15µm65.0%82.0%85.0%95.0%98.0%100%
10µm50.0%63.0%65.0%85.0%97.0%99.9%
5µm25.0%35.0%30.0%50.0%80.0%90.0%
2µm10.0%48.0%
D50 (µm)10.07.08.04.52.52.1
Bulk Density0.860.830.780.630.560.50
Oil Absorption (g/100g)~21~22~24~27~31~32.5
Whiteness8182.58384.58688.5
CIELAB Color L:93.094.094.595.596.0096.50
CIELAB Color a:-0.50-0.50-0.50-0.50-0.50-0.50
CIELAB Color b:4.804.704.604.204.103.85
Hardness (mohs)6.06.06.06.06.06.0
pH8.98.98.99.19.29.3
Moisture0.3%0.3%0.3%0.3%0.3%0.3%

Chemical Properties

SiO2~ 61.50%
Al2O3~ 20.80%
Fe2O3< 15%
TiO2~ 0.03%
Na2O~ 8.40%
K2O~ 6.10%
CaO~ 0.75%
MgO~ 0.10%

These oxides primarily exist in nepheline and alkaline feldspar, and there is no free crystalline silica present in APNS.

Please note, other grades and specifications are available upon request.

Download Spec. Sheet