What is Nepheline syenite
Nepheline syenite also called Phonolite or Ditroite is a naturally occurring, silica-deficient, anhydrous sodium-potassium alumina silicate with a U-Pb titanite age of 230.6 ± 3.5 and a zircon age of 230.6 ± 2.4 Ma. No free crystalline silica is detectable in the mineral complex. Although feldspar-like in its chemistry, mineralogically it is an igneous rock combination of nepheline, microcline, albite, and minor minerals like mica, hornblende, and magnetite. The rocks are mostly pale colored, grey or pink, and in general appearance, they are not unlike granites, but dark green varieties are also known. Phonolite is the fine-grained extrusive equivalent.
Nepheline is a feldspathoid (also called FOID), a solid-solution mineral, that does not coexist with quartz; rather, nepheline would react with quartz to produce alkali feldspar. They are separated from ordinary syenites not only by the presence of nepheline but also by the occurrence of other minerals containing good amounts of alkalies and rare earth.
Application of Nepheline syenite
Nepheline syenite acting as a micronized functional filler and extender used as a performance enhancer in a broad range of paints, coatings, adhesives, sealants, and inks. Excellent brightness, tint retention, and weatherability can be obtained in exterior paints by applying this material. Improved color, sheen uniformity, chemical and stain resistance, and durability result when Nepheline syenite is used in interior paint formulations. It is easily dispersed in all conventional vehicle systems while low oil absorption permits high loadings in adhesives, sealants, and aqueous and alkyd-based paints. The fine grade offers cost-effective gloss and sheen control and while adding texture and application versatility in a wide range of uses. The extra-fine grade is preferred for higher gloss coatings and is also the preferred choice for powder and clear paint systems.
Phonolite is often favored over feldspar in coatings over its silica-free nature and is an effective alkaline buffer. If an exterior coating is sufficiently permeable, however, the nepheline component is subject to be attacked by acid rain and acidic atmospheric moisture which will eventually result in the frosting of deep tones, therefore Feldspar is preferred in this case. An application of emerging interest for nepheline syenite is powder coatings. Low resin demand allows for low melt viscosity and high loadings while Improved abrasion resistance and melt flow have been noted.
Nepheline Syenite has been a standard material in the ceramic industry for many years and is very popular for its whiteness. Nepheline syenite melts lower than feldspars. For example, it is possible to make a very white vitreous medium-temperature porcelain. Like feldspar, Nepheline Syenite is applied as a flux in porcelains, vitreous and semi-vitreous clay bodies and glazes. It also contributes high alumina without associated free silica in its raw form.
Phonolite has very low tint strength, contributing minimal color at high loadings, thus allowing the maximum development of deep tone and pastel colors with minimal colorant. Film reinforcement, chemical stability, and resistance to chalking promote high tint and gloss retention on prolonged exterior exposure. A relatively coarse, Hegman 4 grind of Phonolite is typically used to achieve the optimal balance of properties.
To summarize, Nepheline syenite is supplied as 3 grades, Functional Grades and Ceramic grades as above mentioned and also Glass Grade which serves as a superior fluxing agent.
Our Supply:
Iran by having reserves of more than 5 billion tons of nepheline syenite is one the niche and untapped sources of the material providing competitiveness and economical chances of supply. At Zista Group we have prepared a professional supply chain from Mine to consumer of the material with the below estimated specifications and packaging options:
| OXIDE | Al2O3 | MgO | Fe2O3 | TiO2 | SiO2 | Na2O | K2O | CaO | L.O.I |
| % | 23.31 | 0.08 | 0.18 | 0.02 | 58.02 | 9.50 | 6.78 | 0.94 | 1.36 |
| Reside on a 45µm Sieve: 3% Max | |||||||||
Available Packaging:
- Direct in Jumbo Bags
- 25 kg Bags, Palletized/Loose