What is cold grinding or cryogenic grinding?

Cold grinding – also known as cryogenic grinding or cryogenic milling – describes the process in which liquid nitrogen is added to the substances to be ground in order to achieve particularly high grain fineness with consistent quality during micronization. This process of fine grinding is mainly used for soft, flexible or moist materials, as these are often difficult or impossible to grind. As soon as the grinding material is cooled, the material properties change during cold grinding: The material becomes hard and brittle – thus enabling extremely fine grinding processes. This prevents the material from fusing and sticking together during micronization. In the case of spices, aroma and flavors can be lost due to the high temperatures generated by the grinding energy introduced. In addition, there is a risk of oxidation and even dust explosion

Cold grinding is suitable for many materials, such as:

• Thermoplastic polymers
• Rubbers / Elastomers
• Waxes
• Spices
• Drugs

The advantages of cold grinding at a glance:

• High ground material output
• High percentage of fine and ultra-fine material
• Low specific energy demand
• No fusion or merging of temperature sensitive plastics
• No thermal damage thanks to a controlled grinding temperature
• Preservation of flavors during grinding of spices
• Protection from dust explosions

At Ebbecke Verfahrenstechnik AG, cold grinding is performed in a cryogenic mill, which is also the reason it is known as cryogenic milling or cryogenic grinding.