Making Surfaces Safe with Rock Salt
A combination of factors working together are responsible for the current bad weather, which has seen plummeting temperatures along with lots of snow and ice across the country. Such weather is responsible for major disruption, especially to road travel, with the slippery surfaces causing thousands of delays and accidents.
Around Greenland and Iceland, deep low-pressure systems have formed, pulling super-chilled polar air down into the UK. The balance of airflow in the Northern Hemisphere has been skewed as a result of these systems, which are partly accounted for by a dip in solar activity. The Met Office has predicted a 'little ice age', with temperatures dropping lower than they have in a decade right across the UK.
One of the most effective ways of reducing the problems caused by snow and ice on roads and pathways is the application of rock salt, also referred to as 'grit'. When applied to frozen surfaces, rock salt produces a solution of brine which, as its freezing point is lower than that of plain water, causes the frost, ice and/or snow to melt and makes the surface safe once more.
Known to science as 'granular sodium chloride', rock salt's ice-melting properties were first discovered in 1938. The practical application of the substance in melting ice on roads and walking surface was immediately recognised and rock salt was being used widely for this purposes by as soon as 1941. A study carried out by researchers at Marquette University in Wisconsin found that the overall incidence of car accidents is reduced by a massive 88% on roads treated with rock salt.
Today, many millions of tonnes of rock salt are used on roads, pathways, driveways and other surfaces all over the world. The salt, which was formed when ancient oceans evaporated, is mined using dynamite and large shovelling machines from the deep underground seams where it is found. After being carried to the surface on many miles of conveyors, the giant slabs are crushed into familiar rock salt.