The spirals are designed to separate heavy and light sands from each other. This is achieved using gravity, water and centripetal forces. The Raw material sand is fed into a hopper and mixed with water to create a slurry. This is then pumped to the top of the spiral apparatus where it is fed down one of 2 sets of spirals, one is shallower than the other, this will affect the outcome of the desired end product.
As the slurry makes its way down the respective spiral, the heavier mineral sand stays closer to the centre and the lighter minerals are flung further out. When it reaches the bottom of the spiral it is separated into 1 of 3 gates, the closest to the centre being the heavy concentrate, the middle being the midlings and the furthest out being the tailings. These then make their way down a respective hose where it is collected to be further processed.