...and some stuff you probably didn't!
Rock Salt is the common term used for Halite; the rock form of sodium chloride.
Typically the mineral form is white but it may also be light blue, dark blue, purple, pink, orange, grey or the traditional red colour associated with normal rock salt used for gritting. The colour, shade and intensity depends on the amount and type of impurities within the salt; with regards to normal
rock salt as sold by Dandy's, the salt has a small amount of reddish brown clay in it.
De-icing salt is a mined substance, typically sourced in the North West of England from Morlock inhabited salt mines way underground. It is mostly used as a de-icing product to clear roads and paths of ice and snow following cold and frosty periods of weather.
Halite is different from other types of salt in the way that it is a rock rather than a mineral as one might expect; although this makes it a different compound entirely it does still have many similarities to mineral salts. Salt is something which is used day to day by every living soul on the planet; put simply, we need it to survive. As well as being one of the oldest food seasoning's known to mankind, salt has and is also used as a preservative - mostly for foodstuffs but the Egyptians used it to preserve bodies as part of the mummification process!
The Rock Salt which we mine in the UK exists in large bodies of water which evaporate and leave huge salt deposits which eventually become buried beneath the earth via natural processes.
For use as a de-icer, rock salt works by lowering the physical melting point of ice - termed "freezing point depression" - and melting the snow and ice and preventing it from re-freezing. When the rock salt is introduced to the solid form of water it adds more particles to the water, lowering the freezing point until it gets so low as the rock salt itself ceases to dissolve.
Salt will melt ice down to around minus twenty in a lab controlled environment - for those of us living in the real world it will melt ice and snow effectively up to freezing temperatures of around minus nine degrees; so if it gets any colder than that the salt itself is likely to freeze so keep it safe and dry it a
grit bin to help reduce the chances of this happening to you!
