14. Brick and other ceramic products

Abstract

Clay has been used in a wide range of ceramic products for thousands of years and continues to be a major component in most ceramic bodies today. Fiebinger (1997) states that the annual worldwide production of clay is nearly 400 million tonnes. In the top 50 ranking of extracted minerals and materials, clay is placed 8th with respect to quantity, and 19th in terms of value. Over 90% of the annual tonnage is utilized in the heavy or structural clay sector, with the remainder (predominantly ball clays and plastic clays) being used for higher quality or fine ceramic products. The value of the worldwide ceramic production (of all varieties) was estimated at US$ 113 billion in 2000 (Reh 2000). From 1991 to 1999, growth was significant in the advanced ceramics, tile and sanitaryware sectors, but less so in structural ceramics and refractory products, as detailed below: wall and floor tiles ; 70% growth with US$ 14 billion turnover in 1999; advanced ceramics (including the carbon and graphite sector); 63% growth with US$ 40 billion turnover in 1999; sanitaryware ; 50% growth with US$ 12 billion turnover in 1999; structural ceramic sector (bricks, roofing tiles, pipes); 17.5% growth with US$ 23 billion turnover in 1999; refractory products ; <10% growth with US$ 12 billion turnover in 1999. The technical definition of a ceramic product is ‘a product that is composed of polycrystalline, inorganic and non-metallic materials that have been subjected to a temperature of 540°C or more during manufacture