A b s t r a c t . The paper describes the consequential advantages of the use of inorganic binders, particularly soluble sodium silicate, in the aspect of the environmental protection. Nanostructure of the soluble sodium silicate as a silicate colloid is described. Research of the structure of the soluble sodium silicate is executed with the use of the PCS method (Photon Correlation Spectroscopy). Characteristic parameters of the nanostructure of the soluble sodium silicate and the method of the estimation of the quantitative structure of the colloid are introduced. It has been proved that the nanostructure of the soluble sodium silicate has an essential infl uence on its proprieties as binders of the moulding sands. Mechanical characteristic of the moulding sands executed with this binder are dependent on the kind of the nanostructural characteristic of the soluble sodium silicate.
Key words: nanostructure, colloid, soluble sodium silicate, moulding sand, casting, environmental protection.