Adverse Weather Solutions Information – Rock Salt Geology
Rock salt or Halite to give it it’s proper name is a mineral formed from sodium chloride. It’s chemical formula is NaCl and this also includes other variations of salt such as common salt and table salt. Rock salt tends to be the industrial name used for Halite.
It forms as isometric crystals and is typically colorless or white but may also be other colours depending on the amount and type of impurities contained within it. The salt occurs in beds of sedimentary evaporite minerals. This is caused by large lakes and seas drying up. These salt beds can be hundreds of metres deep.
Most of the rock salt used for gritting roads in the UK comes from mines of ancient underground salt deposits in Cleveland, County Antrim and Winsford in Cheshire and four of the surrounding towns – Middlewich, Nantwich, Northwich and Leftwich are all historically related to salt production. The “wich” (or sometimes “wych”) in their name is often associated with brine springs or wells.
The Salt Association who are the trade body for salt producers, estimate that the UK’s salt mines to have about 225km (140 miles) of tunnels. TheUK salt reserves are extensive, with an estimated 500 years capacity at current extraction rates.
Halite known as Rock Salt
Gritting with Rock Salt eases snow clearing