Ground walnut shells have been used for centuries for things such as polishing wood and making paint. However, ground walnut shells have been discovered to have some surprisingly practical applications in recent years. They are a cost-effective and environmentally-friendly alternative to traditional materials, making them popular for various uses.

What are Ground Walnut Shells?

Ground walnut shell is a tough yet durable and biodegradable abrasive material. They come in two varieties: standard-grade English walnut shell or Juglans Regia and filtration-grade Black walnut shell or Juglans Negra. These shells have exceptional hardness, and their specific gravity ranges between 1.2 and 1.4. The Mohs scale displays its hardness at 3.5, while the Rockwell hardness test shows its toughness at 91.

Popular Applications of Ground Walnut Shells

Industrial Blasting

Industrial blasting is a process in which tiny spherical yet abrasive particles are propelled at a substrate using compressed air or water. It is an efficient, economical, and faster cleaning process that removes rust, paints, and dirt from buildings, cars, furniture, and steel.

Since it is an eco-friendly material, ground walnut shells are often used in industrial blasting applications. It can remove coatings, paints, and dirt without damaging substrates. In addition, under specific parameters, industrial blasting using ground walnut shells facilitate selective coating removal. This process removes the top coating without affecting the underlying layers. 

Ground walnut shells offer economic advantages in the industrial blasting process as it helps to reclaim and reuse media for numerous blast cycles. It is also an excellent yet cheaper alternative to sandblasting.


Fillers are an advantageous material in the construction, adhesives, furniture, plywood, paint, resin, and rubber industries. Ground walnut shell flour is utilized as fillers in these industries. In manufacturing, walnut shell flour is used as an eco-friendly additive. It is used in burn-out applications to improve ceramic porosity. Ground walnut shell flour is also an anti-skid additive for floors, stairs, pools, and ramps.


The Black walnut shell is an ideal material for filtration processes. The shells are ground into a fine powder using equipment like Rotormill and mixed with water. The powder absorbs contaminants and suspended particles from the water, making it safe to drink. This type of water purification system is often used in areas with limited access to clean water.


Walnut shells have been used in the cosmetic industry for over three decades. They are utilized to make a wide range of bathing products like soaps, lotions, and scrubs. In addition, this biodegradable material is a superb alternative to polyethylene-based microbeads used in these applications. 

Pet Litters

English walnut shell granules are a significant ingredient in pet litter. This bio-degradable yet eco-friendly material minimizes moisture absorption and controls bacterial infection. 


Ground walnut shells can also be used to create a variety of industrial adhesives. The shells are ground into a powder and mixed with an adhesive to create a strong, durable bond. This type of adhesive is often used in the aerospace industry, where it is used to bond parts together in extreme temperatures. It is also used in the medical field to bond prosthetics to patients' bodies.

The Lesser Known Applications of Walnut Shells

People use walnuts for cooking and baking, and walnut shells are oftentimes disregarded. Reusing or recycling them for various creative purposes like arts, crafts, and fun-filled group activities for children and adults is possible. 

These walnut shell crafts include ornaments, writing ink, Easter egg dyes, toy baskets, boats, etc. Other applications for walnut shells include de-flashing, deburring, tumbling, and filtration.

Milling Equipment From Prater

At Prater Industries, we can design and build custom processing equipment to meet your specific needs. Contact us to learn more about how our machinery can help improve material processing efficiency.