How is ice melted by slat?
29th May, 2015
Did you know that every year councils up and down the country spend approximately £150 million spreading 2 million tonnes of salt across the UK's many motorways, trunk roads and main roads? On top of that it is likely that as home and business owners you will have also spread salt across your car parks, walkways, patios and driveways.
When ice begins to form we all instinctively reach for the salt from the cupboard and it is something we do without thinking. But why salt and how does it cause the ice to melt?
The Scientific Bit…
At school we were all taught that ice forms when the temperature of water falls to 0°C (32°F). Well, when you add salt to liquid water it causes the salt to dissolve and the freezing point of the water to fall. The more salt you add, the lower the temperature at which the water will begin to freeze. For example:
- A 10 percent salt solution reduces the point at which water freezes to -6°C (20°F)
- A 20 percent salt solution reduces the point at which water freezes to -16°C (2°F)
If you have ever watched salt melting ice you will see that as the salt comes into contact with the ice, the area immediately around the grain of salt will begin to melt. The melting will then proceed to spread outwards from this point.
However, for the process to work it is important that the salt can dissolve into the structure of the water. If the surface you are spreading onto is already at a temperature of -9°C (15°F) or lower, chances are spreading salt will have very little impact. The solid salt will be unable to penetrate the structure of the ice and the dissolving process cannot begin.
Organising Your Winter Maintenance Plan
The lesson we can take from this is that it always pays to be proactive when it comes to gritting, as opposed to reactive. Gritting at the first indication of possible ice will have far more effect than spreading grit once the ice has already formed and solidified. It therefore pays to put a winter maintenance plan in place now to ensure that your site is suitably protected come the winter months.
At Ice Watch we have extensive experience as gritting contractors and a fantastic understanding of regional variances. Our team of gritting contractors are based across the UK, with a contractor based within a 10 mile radius of our customers' sites. Each holds up to 3 weeks of salt stocks in reserve and we are proud to have never run out.
Combine this with our postcode specific weather monitoring service and we are able to ensure that our customers' sites are protected in even the most extreme of British winter weather.
We prepare a bespoke winter maintenance plan to suit the individual requirements of each customer's site. If you would like to arrange a FREE consultation, or to arrange a quotation for your business, please do not hesitate to get in touch.