GB417124A - Improvements in or relating to the manufacture of bricks, blocks, slabs, tiles and like products, suitable for building and other purposes - Google Patents

Abstract

417,124. Bricks &c. BERRY, A. F., 125, Strand, London. March 23, 1933, No. 8828. [Class 87 (i).] In the manufacture of bricks from a mixture of crushed burnt clay and raw or unburnt clay, the main bulk of clay used is broken up, burnt, and crushed to a suitable degree of fineness before being mixed with a relatively minute percentage, e.g. 5 to 7 per cent, or less than 5 per cent, of unburnt clay. A small proportion of Portland cement or equivalent cementitious material may be added to the mixture of clays or to the burnt clay before it is mixed with the unburnt clay. To impart a colour of the desired kind to the bricks, a small amount of coloured clay or coloured pigment or a mixture thereof may be added to the main bulk of broken up clay before it is burned or to the mixture of burnt and unburnt clays. The plant used for making the bricks is of known type, the main bulk of clay used being fed in a broken up condition into the upper end of a kiln and burned therein, the burnt clay being conveyed to milling apparatus where it is crushed to the desired degree of fineness and mixed with the small amount of unburnt clay, the mixture being then delivered to a moulding press or presses and formed into bricks. The bricks are fed from a drying tunnel to a second kiln where they are burnt, the burnt bricks passing through a cooling tunnel. The bricks while passing from the moulding press or presses to the drying tunnel may be coated with a slurry consisting of a mixture of a suitable colouring material and water, as described in Specification 417,125. The bricks may be pressed to shape between suitable dies so as to contain tapering holes, recesses, or cavities.