Salt mining

Underground salt mine
Underground salt mine, Reno County.

 

Salt is mined in Kansas using two methods: underground mining and solution mining.

Underground mines in Kansas range in depth from 500 to 1,000 feet. With the underground room-and-pillar method of mining, a shaft is drilled through overlying rock to reach the salt deposit. The salt is removed in a checkerboard pattern so that large square caverns alternate with square pillars of salt left in place to support the rock above. Miners blast the salt into manageable pieces, which are then crushed and taken to the surface through the shaft in large buckets. Active underground salt mines operate in Lyons, Kanopolis, and Hutchinson. Because of impurities (mostly shale and anhydrite), salt from these mines is used mostly as road salt for melting ice.

Solution mining of deep salt beds started in the 19th century in central Kansas and is still used today. In this process, freshwater is forced down a cased well to dissolve the salt and produce brine (water heavily saturated with dissolved salt). The brine is pumped to the surface and evaporated to recover the salt. Evaporation plants produce pure salt to be used as table salt and in food processing, animal feeds, and water softeners.

In Hutchinson, underground space created by salt mining is leased for high-security storage. The constant temperature and humidity provide an ideal environment for fragile items such as the original film from classic movies, paintings, and collections. A salt museum also has been established about 650 feet underground in a Hutchinson mine.

The KGS public information circular, Salt in Kansas, provides more details and includes information about the relationship between abandoned salt mines and the 2001 natural gas explosions in Hutchinson, sinkholes caused by underground salt dissolution, and the natural Quivira salt marshes in Stafford County.

Resources

Buchanan, R., 2010, Kansas Geology: An Introduction to Landscapes, Rocks, Minerals, and Fossils (2nd ed.): Lawrence, Kansas, University Press of Kansas, 240 p.

Buchanan, R., and McCauley, J. R., 2010, Roadside Kansas: A Traveler's Guide to Its Geology and Landmarks (2nd ed.): Lawrence, Kansas, University Press of Kansas, 392 p.

Salt in Kansas: Kansas Geological Survey Public Information Circular 21.

Kansas Rocks and Minerals: Kansas Geological Survey Educational Series 2.