Handbook of lithium and natural calcium chloride. Their deposits, processing, uses and properties / Руководство по литию природному хлориду кальция. Их месторождения, получение, использование и свойства

Lithium is one of the most interesting of the industrial minerals, occurring primarily in the unusual lithium pegmatites or in the very few high-lithium brine deposits. Many of the lithium pegmatites contain separate masses of different minerals (i.e. they are highly zoned), with the crystal size often being very large, such as up to 1–14 m long. There may be as many as 13 distinct and separate massive zones of single predominant minerals in the pegmatite, including up to six different lithium mineral zones, and several zones with other rare elements such as tantalum, niobium, tin, tungsten, cesium and rubidium. The pegmatites appear to be the final magma that had been forced up into fractures of previously crystallized granite-type rock, considerably enlarging the fractures, and then slowly cooling and fractionally crystallizing its lithium and granitic components. Presumably the lithium pegmatites resulted from a flowing magma that had slowly cooled with some mixing, allowing the initial crystallization of the less soluble compounds such as iron and manganese silicates. This left a granitic-type melt containing the more soluble and lower-melting lithium silicates, as well as any rare metals that happened to be present in concentrations too small to be initially crystallized. Most of the minerals in the lithium pegmatites can be easily separated by selective mining and conventional mineral dressing techniques, often allowing a number of products to be recovered. For example, in one deposit separate concentrates of the lithium minerals lepidolite, petalite, spodumene, amblygonite, eucryptite and bikitaite have all been sold, along with tantalite (tantalum ore), beryl (beryllium), pollucite (cesium), cassiterite (tin) microlite, both K- and Na-feldspar, mica and quartz. With the large deposits this makes the mining and purification of lithium mineral concentrates relatively inexpensive, and they can be used directly in some lithium applications, such as in ceramics, various formulations of glass, and in producing aluminum. <...>