Special Milling and Activation Devices

Solids are sometimes fragmented in shock tubes by the action of shock waves in liquids or gases. The breakdown of kidney stones - known as lithotripsy - by shock waves is an example of this type of apparatus. Typically, shock tube applications are limited to laboratory experiments. 

Ultrasound reactors are used quite often for the low-intensity treatment of solids in liquids. Examples of industrial-scale ultrasound reactors are the Reverbatory Ultrasonic Mixer with 16 kW total power input and 0.2 m3 min-1 flow rate, the 

Electrical discharge-assisted mills use ball milling with high voltage in spark-milling or glow-milling conditions. This type of mill is used to prepare nanomaterials [35]. 

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