Cryogenic grinding is a technology used for pulverizing materials so as to increase productivity and bring down the power costs. It has proved to be effective, especially for materials like rubber and plastics.
Prologue
The term Cryogenics is derived from a Greek word, meaning production or creation by means of cold. And, this is exactly what the process involves- cooling a material and then reducing it to a small size.
With the soaring prices of raw materials and energy along with the increasing difficulty to dispose waste materials safely, it is crucial to recover resources. Cryogenic grinding not only grinds tough materials efficiently, but also facilitates cryogenic recycling of multi-component scrap and hard composite materials.
How is Cryogenic Grinding Beneficial?
The very fact that Cryogenic grinding is highly efficient in grinding tough and elastic materials, which otherwise needs high energy and long cycle times, is highly beneficial. The embrittlement of the material makes it easy to grind it to crumbs or fine powder with minimum use of energy. The capital investment is also lower in addition to minimum loss of volatile elements.
Problems of Conventional Grinding
Now that we have seen the benefits of cryogenic grinding, we’ll take a quick look into the problems faced with conventional grinding technologies:
- Gumming and clogging of the mill
- Loss of etheric oil
- Oxidation and other related degradation
These, being the primary drawbacks, the cryogenic process get over all of them in addition to being advantageous in its own ways. It retains high levels of etheric oil, prevents oxidation as well as rancidity, increases throughput, saves power, and reduces microbial load,
Materials That Can Be Processed Using Cryogenic Grinding
This process can be used to treat materials like elastomer, polyester, synthetic rubber, composite materials, copolymers, cellulose ether, spices, thermoplastics, and heat sensitive polymers.
For recycling, it is used to recover many waste materials like scrap tires, factory waste rubber, and to breakup the elements in composite materials.
Earning Foreign Exchange
This process finds wide application in the spice industry for grinding spices. Taking advantage of this aspect, the spice industries of our nation can earn significant foreign exchange by exporting more valuable spices instead of exporting them as whole spices. The technology can further be extended to process PVS as well as industrial scrap plastics for recycling non-biodegradable materials.
Looking at its future prospects, all that we can say at this point of time is that cryogenic grinding is a highly viable option if the cost of liquid nitrogen is not formidable. So, once something can be worked out to bring down the cost factor, then it’d definitely be a great technology to work with.