Sample Preparation for Refuse Derived Fuel

Based on the amount of the material and its properties, only a cutting mill can be considered for this task. Furthermore, when considering that in order to avoid cross contamination, the cleaning of the instrument often lasts longer than the actual comminution, consequently only the Universal Cutting Mill PULVERISETTE 19 can be recommended. The mill distinguishes itself through:

• Quick lock
• Cutting rotor removable without tools
• Sieve cassette removable without tools
• No dead spaces which evade the cleaning

If a sieving of 0.5 mm is desired, then most materials can only be prepared with a combination of the cutting mill with the cyclone separator. The cyclone separator generates an air current. It downright draws the materials from the funnel, and acts as a coolant during the comminution and fosters the movement of the material and therefore the passing through the sieve. The finished prepared sample is removed through the cyclone separator into a sample glass.

Tests showed that a pre-comminution for example with a 4 mm sieve and an ensuing fine comminution with a 5 mm sieve, can in no case replace the cyclone separator. Rather the opposite is to be noticed. Are the above pictured foils additionally pre-comminuted, the final fineness of 0.5 mm is no longer obtainable. On the sieve accumulates a film which stops the material throughput. Coarse material whirls in the grinding chamber and therefore keeps the sieve clear.

The same is to be observed with material blends: the more heterogeneous the materials within a sample are, the better they can be prepared. Therefore should material blends not be sorted prior to the comminution. Separated though should be iron parts. Are samples with a non-ferrous heavy metal share prepared, or is the focus on heavy-metal-free preparation, cutting knives of other materials are available.