Comminution is materials processing to break down rock and other raw feedstock into smaller component particles and chunks. This is used in mining and in the production of a wide range of products, including raw materials for construction as well as finished components. Companies can use wet and dry processes, depending on the materials they work with and how they plan to use them. Research and development in this area includes the invention of new equipment, better classification systems, and new uses for waste materials.
In the comminution process, workers pour feedstock into grinding equipment. The equipment can hurl it against the walls of a drum to break it, chew it with heavy duty teeth, grind it in rollers, and use a variety of other methods to break it up. The broken material passes through a series of screens to separate out different components of interest, if needed. This process can be continuous, allowing workers to keep adding feedstock to get newly ground material.
One reason to use comminution is to access valuable trapped minerals. Deposits of minerals usually include a mixture of items, some of which are more useful than others. A company can grind rock, clay lumps, and other materials to get at the most useful and valuable components inside. Materials processing can also include comminution to increase surface area for chemical catalysts, rock used in filtration, and other materials. These materials may be required to meet standards set by a manufacturing organization or a client to ensure consistent, standardized products.
This process is also used to prepare materials like fill sand, aggregate gravel for concrete, and materials for roadbed construction. These materials need to be uniform in size and texture to work effectively. Firms that prepare construction materials may maintain comminution equipment to meet the needs of their customers. A series of fine screens allows them to classify products by grain size and create a high degree of control so customers get products that meet very particular specifications.
Natural processes can create comminuted products as well. Fault lines typically grind rocks, soil, and other materials into smaller pieces. Geologists can take samples to learn more about activity at a specific location. Some of these samples may reveal deposits of useful materials. Researchers who study faults and other geologic activity can examine different comminution processes in nature to learn more about the processes behind the formation of naturally occurring aggregate materials like sedimentary rock.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.