METHOD OF PREPARING EXPANDED CLAY Russian patent published in 2010 - IPC C04B14/12 C04B20/06 

FIELD: chemistry.

SUBSTANCE: invention relates to production of construction materials and can be used in preparing expanded clay. The method involves mixing clay raw material, an additive and water, granulation of the obtained mixture, drying and burning. The additive used is oil-containing sludge which is neutralised with calcium oxide based reagents and is in form of encapsulated granules and ground spent silica gel - gas industry wastes from drying natural gas. Mixing is carried out in two steps. At the first step clay raw material is mixed with the additive in the following ratio of components, wt %: clay raw material 96-97; neutralised oil-containing sludge 2.8-3.2; spent silica gel 0.2-0.8. At the second step water is added in an amount sufficient for obtaining a mixture with water content of 18-20%.

EFFECT: higher expansion coefficient of the material, lower burning point.

2 cl, 1 tbl