Nepheline grinding mill

Nepheline, also called nephelite, is a feldspathoid: a silica- undersaturated aluminosilicate that occurs in intrusiveand volcanicrocks with low silica, and in their associated pegmatites. It is often found in micaschistand gneiss.

Brief introduction about Nepheline:

Nepheline mainly used for glass and ceramics industry, or as raw material of the refined aluminum.Crushed Nepheline powder is important raw materials of glass and ceramics industry, or as raw material of the refined aluminum. Before processing Nepheline powderfor glass and ceramics industry, you need firstly Nephelinestone to be 265mesh~ 2500mesh. Clirik offers HGM series ultrafine mill and high pressure grinding mill to grind Nepheline stone. And you can choose open circuit or closed circuit powder grinding system according to your real situation.

Nepheline crystals are rare and belong to the hexagonal system, usually having the form of a short, six-sided prism terminated by the basal plane. It is found in compact, granular aggregates, and can be white, yellow, gray, green, or even reddish. The hardness is 5.5 - 6, and the specific gravity 2.56 - 2.66. It is often translucent with a greasy luster.

The low index of refraction and the feeble double refraction in nepheline are nearly the same as in quartz; but since in nepheline the sign of the double refraction is negative, while in quartz it is positive, the two minerals are readily distinguished under the microscope. An important determinative character of nepheline is the ease with which it is decomposed by hydrochloric acid, with separation of gelatinous silica (which may be readily stained by coloring matters) and cubes of salt. For this reason, a clear crystal of nepheline becomes cloudy when immersed in acid.

The mineral is one especially liable to alteration, and in the laboratory various substitution products of nepheline have been prepared. In nature it is frequently altered to zeolites(especially natrolite), sodalite, kaolin, or compact muscovite. Gieseckite and liebenerite are pseudomorphs.

Two varieties of nepheline are distinguished, differing in their external appearance and in their mode of occurrence, being analogous in these respects to sanidineand common orthoclaserespectively. Glassy nepheline has the form of small, colorless, transparent crystals and grains with a vitreous luster. It is characteristic of the later volcanic rocks rich in alkalis, such as phonolite, nepheline-basalt, leucite basalt, etc., and also of certain dike-rocks, such as tinguaite. The best crystals occur with mica, sanidine, garnet, etc., in the crystal-lined cavities of the ejected blocks of Monte Somma, Vesuvius. The other variety, known as elaeolite, occurs as large, rough crystals, or more often as irregular masses, which have a greasy luster and are opaque, or at most translucent, with a reddish, greenish, brownish or grey color. It forms an essential constituent of certain alkaline plutonicrocks of the nepheline syeniteseries, which are typically developed in southern Norway.