Improvements in and relating to the manufacture of blocks primarily for building

摘要

Lightweight bricks, blocks &c. are produced by adding up to 1% by weight of a mixture of aluminium, lime and a surface-active agent to a mixture of a major amount of a ceramic material and a minor amount of cement, the materials of said latter mixture being precalcined to destroy their plasticity, adding water which results in the formation of gas bubbles, feeding the material to moulds or formers where it is allowed to set, after which it is removed and fired at a temperature of at least 1000 DEG C. Proportions of 90% or more of ceramic material, e.g. calcined clay or fuel ash, and up to 9% of cement, e.g. Portland cement, are specified.