Feldspar Production by Country 2024

Feldspar, sometimes spelled feldspar, is a large class of minerals containing aluminum tectosilicates, as well as similar compounds based on barium, calcium, potassium and sodium. There are many specific types, with sodium-calcium feldspars being the most common. Feldspars are extremely common, comprising about 60 percent of the Earth's crust. However, commercially viable deposits of high-grade feldspar are far less common.

Formation

Feldspars are primarily formed when they crystallize from magma as igneous rocks, but they're also found in many types of metamorphic and sedimentary rock. Concentrated feldspar generally requires volcanic activity, so these deposits are only found in a relatively few places on Earth.

Applications

Feldspar is primarily used in ceramics and glassmaking, with minor uses including fillers in paint, plastic and rubber. Two-thirds of the feldspar consumed in the US is used to make glass, including glass containers and fiberglass. Uses of the remaining third include ceramics like tile, electrical insulation and tableware, in addition to fillers.

The applications for a particular type of feldspar depends on the specific minerals it contains. For example, feldspar that contains potassium oxide (K2O) or sodium oxide (Na2O) may be used as a flux in glassmaking, while those containing aluminum oxide (Al2O3) and calcium oxide (CaO) may serve as stabilizers. In addition to being an important source of aluminum oxide, advantages of feldspar for glassmaking include its low iron content and lack of volatile substances, resulting in a low amount of waste.

For ceramics, feldspars are mostly used as a flux that assumes a glassy phase when an object is fired, which promotes vitrification. They're also used in glazes as a source of alumina and alkalies. The specific product has a great effect on how feldspar it contains. For example, dental porcelain contains up to 80 percent feldspar, while high-tension porcelain for electrical use only contains 25 to 35 percent porcelain.

Production

The US Geological Survey (USGS) estimates the global production of feldspar at 26 million tonnes, with little change during recent years.