There is a large number of relatively small mining sites in Illinois. In 2004, the state accounted for 2.3 percent of non-fuel mineral production in the United States, and its mining industry employed nearly 10,000 people. Many common resources are mined in Illinois, like sulfur, zinc, natural gas and lime. There are also dozens of sand and gravel mining sites in the state, which are often used for construction purposes.
Vermiculite resembles mica and consists of shiny flakes. The material expands as much as eight to 30 times its original size when heated to a high temperature. It is lightweight and fireproof, and is used in insulating material for attics and walls and to fireproof steel support beams in buildings and steel pipes. Companies in Girard and De Kalb process vermiculite.
Fluorspar is a fluoride of calcium and is used directly and indirectly in the production of materials like aluminum, gasoline, insulating foams, refrigerants, steel and uranium fuel. It speeds up processing, helps purify materials and increases fuel efficiency. Most Fluorspar in the United States is used in the production of hydrofluoric acid. Fluorspar is mined in Cave In Rock.
Perlite is a volcanic glass that is used in tiles and roof insulation products. It expands up to 20 times its size when heated, and is also sometimes used as a pipe insulator or in heat-resistant bricks. It is also used to increase the oxygen content in farming soil and as a filter in the production of pharmaceuticals, chemicals and beverages. Perlite is mined in Hodgkins and Joliet.
Tripoli is an abrasive mineral used for sharpening industrial tools and polishing or buffing jewelry or gems. The mineral polishes materials without scratching them, and it continually breaks down to smaller granules. No other known minerals possess these characteristics. It is also used as a filler and texturizer in paints and concrete. Tripoli is mined in Elco.
