Laboratory coat and work gloves must be used, as well as safety glasses and hearing protection. Before starting the air extractor has to be turned on (green button 'in', EK 53 next to the door) and the valve of the machine has to be opened (other valves remain closed if possible). Check if the machine, particularly the 'jaw' (the big heavy metal block) is clean. Use the compressed air wire brush.

Click for a picture of the machine

THE PRINCIPLE OF CRUSHING

The jaw crusher consists of a detachable and a fixed jaw.

Click for a schematic overview

The distance between the jaws can be adjusted (0.5-10 mm) and determines the maximum passage and thus the eventual grain size of the crushed material. The crushing movement is made by the fixed jaw.

EQUIPMENT

• Sieve of 250µ + collecting container
• Stainless steel bowls

METHOD

The sample must be broken coarsely at first. Put the jaw into the machine, lower the splash shield (mind protection) and set the adjustable jaw distance in position 2. Place the stainless steel container into the bottom part of the machine. Switch on the machine with the on/off button on top. Insert the sample by depositing one rock fragment at a time into the open space at the top. Close the opening with the lid and have the machine "empty its mouth" before inserting the next fragment. Afterwards sieving with 250 µ will take place and the procedure will be repeated in positions 1 and 0.5.

CLEANING

Afterwards the equipment must be cleaned thoroughly. Take out the jaw and work it with the compressed air wire brush. The fixed part of the jaw crusher must be cleaned similarly. The rest of the machine has to be cleaned with the vacuum cleaner (button on the front of the casing). The sieves used must be shaken in the ultrasonic cleaner. The work top and the floor must be wiped off with a wet cloth.