Underground potash and magnesium crude salt extraction
This is how we mine our potash and magnesium crude salts
K+S KALI GmbH extracts potash and magnesium crude salts at six mines in Germany with an annual production output (at full capacity) of up to 7.5 million t. of finished products.
Below we describe the mining process for potash and magnesium crude salts.
Boring large holes in the rock
First the large hole drilling machine is used. Over seven metres long, it creates three large boreholes with a diameter of 280 millimetres in the salt rock. During blasting, the rock should be able to spread itself into these hollow spaces.
The excavation vehicle then removes the drillings from the wall.
Blastholes are now drilled around the large boreholes.
These holes are filled with explosive and prepared for blasting.
Blasting in the empty mine
For safety reasons, the blasting always takes places between work shifts, when the miners have already left the mine and are on the surface.
Crushing in the crushers
Large mechanical shovels then pick up the blasted material and take it to the crushers. There it is crushed ready for transport. The crude salt reaches the shaft via conveyor belts that are several kilometres long, where it is brought directly to the surface or stored in bunkers.
Removing loose material
Meanwhile, with the aid of scaling machinery shell-shaped chunks of rock which were loosened from the roofs of the mines (the so-called ceilings) or from the walls are removed carefully, so that they do not become detached unexpectedly.
A small loader removes the loose scaled material that has accumulated.
Dowels for the ceiling
The roof areas are secured by the roof-bolt drill machine. They use threaded rods measuring 1.2 metres long, with an expansion sleeve at their tip, which, similarly to an oversized dowel, connect the salt layers to each other and thus make them more stable.
The cycle begins once again.