Bricks Without Clay

Progress, Volume X, Issue 11, 1 July 1915, Page 364

Bricks Without Clay

Making bricks without clay is what is now proposed, and a plant is being built in Illinois. According to the "Railway Age Gazette," the process consists in chemically combining any coarse material containing silica, with a binder of finely divided particles of silica, alumina, potassium, or sodium in suitable proportions to insure a binder with a low fusing point, as compared with the coarse body material.

The bricks are moulded under high pressure, preferably in a dry state, and are fired in a manner similar to that used in making ordinary brick, but the time required is not nearly as long. Bricks made by this process have been tested and have shown very satisfactory absorption qualities, and have withstood a temperature of 2,900 deg. Fahr. without cracking or showing damage. They have undergone crushing tests of 20,000-lbs. per square inch without failure. The samples examined show a texture capable of taking a high polish, and the . grain is so fine that clean cut carving is possible; but these qualities evidently depend on the character of the material out of which the bricks are made

It is proposed to use the tailings from coal mines at the new Illinois plant, and it is stated that, on account of the wide variety of materials that can be used in the new process, including many waste products, these bricks can be profitably made in localities where ordinary brick cannot be produced on account of the absence of suitable clay.