Oyster and mussel shells are non-biodegradable. They pollute the land and water when discarded indiscriminately. Using them as raw materials for concrete tiles could solve the problem of disposal. The procedures and formula in making concrete tiles from marble dusts, chips and white cement were followed for oyster and mussel shells. Ground oyster and mussel shells were mixed separately with white cement on a 1:1 ration.
The mixture was compressed on a mold. fter drying, the finished products showed acceptable color and texture comparable to commercial concrete tiles. • Wash broken clam shells in a bowl of soapy water. If the shells still have traces of animal tissue inside, soak them in a 50 percent solution of bleach and water for 10 minutes before washing them. Rinse the shells and scrub them with a stiff brush to remove any residual dirt and barnacles. Pick out debris in small areas using a dental pick.
Sand the surface of the shells with sandpaper, starting with a rough grit and working up to a fine grit to buff the shells to a smooth, shiny finish. Roll out a 1/4- to 1/2-inch sheet of ceramic clay. Flip the slab of clay over and roll it out on the other side to prevent the clay from warping during the firing process. Cut out tile shapes using tile cutters. Press clam shell pieces firmly into the clay in any pattern you wish. Allow the clay to dry out in a sunny, dry spot prior to firing.
Dust a kiln shelf with silica sand and place the tiles in the kiln on a tile setter or stacked on top of each other. Fire the kiln according to your clay’s recommended temperature settings. Allow the tiles to cool after firing. Coat the tiles with a glaze recommended for use with your specific type of clay. Glaze will add shine and color to the tiles and will seal pores, making the tiles waterproof. Place the tiles in the kiln on a tile setter. Fire the glazed tiles according to the recommended temperature for your glaze type.