An official website of the United States government
Here's how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Statistics and information on the worldwide supply of, demand for, and flow of the mineral commodities kyanite, andalusite, and sillimanite
Kyanite, andalusite, and sillimanite are anhydrous aluminosilicate minerals that have the same chemical formula, Al2SiO5, but differ in crystal structure and physical properties. When calcined at high temperatures (around 1,350° C to 1,380° C for kyanite and slightly higher for andalusite and sillimanite), these minerals are converted to mullite, 3Al2O3·2SiO2, and silica, SiO2, which are refractory materials. In the conversion to mullite, 1 metric ton (t) of mineral concentrate yields about 0.88 t of mullite. Synthetic mullite is made by heating mixtures of alumina and silica or bauxite and kaolin at around 1,550° C to 2,000° C. Refractories are heat-resistant materials used in high-temperature applications such as furnaces, boilers, ladles, and kilns, in the metallurgical, glass, chemical, cement, and other industries.
Subscribe to receive an email notification when a new publication is added to this page. On the Questions tab of the subscriber preferences page, select "Kyanite" and any other options in which you may be interested. Please see the list services page for more information.