Jun . 05, 2025 15:08
Shell powder, predominantly sourced from marine mollusk shells (such as oyster, scallop, and clam shells), is a versatile natural material with a rich history of use in various industries.
The production process starts with the collection of discarded shells from seafood processing plants, coastal areas, or fisheries. These shells are first thoroughly cleaned to remove any organic residues, salt, and impurities. Subsequently, they undergo a drying process, either through natural sunlight or in industrial dryers, to eliminate moisture. Once dried, the shells are crushed into small pieces using mechanical crushers and then further ground into fine powders of different particle sizes, typically ranging from 100 to 3000 mesh, through ball milling or other grinding techniques. Some advanced production lines may also include additional steps like high-temperature calcination to enhance certain properties, such as increasing the reactivity of calcium carbonate in the shells.
Chemically, shell powder is mainly composed of calcium carbonate (CaCO₃), often accounting for over 90% of its composition, along with trace amounts of other minerals like magnesium, potassium, and trace elements. Its unique physical and chemical properties, including high whiteness (usually above 90), fine particle size, good dispersibility, and chemical stability, make it highly valuable.
In the construction industry, shell powder is used as an additive in paints and coatings. It improves the paint’s hiding power, adhesion, and weather resistance, while also reducing costs as a partial substitute for titanium dioxide. In the production of cement and concrete, it can enhance the workability and mechanical strength of the mixture. In the plastics industry, shell powder acts as a filler, reinforcing the mechanical properties of plastics, increasing their hardness, stiffness, and dimensional stability, and reducing the overall cost of plastic products.
