Process for the production of steam hardened cemented products from waste products of the soda industry

摘要

Cement products are made from waste products of the soda industry, namely lime granules residual from the slaking of burnt lime, and comprising calcium carbonate, calcium oxide, and di- and tri-calcium silicates and aluminates, and the solid distillation sludge comprising calcium carbonate and calcium oxide and from which calcium chloride has been removed, by working up these products with a material of high silicic acid content and water, and casting and subsequently steam hardening the mixture. The material of high silicic acid content may be sand and/or quartz powder or meal. Optionally a hydratable silicate material such as Portland cement or basic blast furnace slag is included to increase the compressive and tensile strength. A leavening agent such as 0.035% by weight aluminium paste may also be included to yield porous products. A preferred composition consists of 30% by weight lime granules, 30% distillation sediment, 35% quartz meal, and 5% hydratable silicate, to which 45% of water is added, based on the total solids weigth.