The importance of salt

Question 1

What is the result of MINING as a method of extracting salt?

Answer 1

This method of extraction leaves the salt with insoluble impurities such as reddish clay. This kind of salt is used to put on roads during freezing weather and does not need to be pure.

Question 2

What is SOLUTION IN WATER as a method of extracting salt?

Answer 2

Water is forced down a borehole into rock. The salt dissolves making a solution of brine and this solution is withdrawn to the surface and pumped to a purification plant. Water is evaporated from the brine under a range of pressures making the process more efficient. The salt crystallises and is separated from any remaining brine by filtering

Question 3

What are the environmental impacts of extracting salt?

Answer 3

Large underground caverns are formed, leading to the bedrock collapsing and causing the Earth’s surface to lower (This is called SUBSIDENCE)

Question 4

How can subsidence be avoided?

Answer 4

By sensibly spacing out the holes created so the surface is supported by a sufficient amount of rock underground

Question 5

Why is salt used in food?

Answer 5

Flavour/preservation

Question 6

What does eating too much salt increase?

Answer 6

Blood pressure

Question 7

What does high blood pressure increase the risk of?

Answer 7

Stroke/heart disease