METHOD FOR PRODUCTION OF EXPANDED CLAY AGGREGATE Russian patent published in 1995 - IPC

FIELD: production of expanded clay aggregate. SUBSTANCE: method for production of expanded clay aggregate includes coating of granules during heat treatment with powdery additive from waste slime of electroplating hydroxides of iron, chromium-nickel, zinc and copper, preliminarily dewatered and ground to grain size of 200 meshes taken in the amount of 1-2 mas. in terms of mass of dry granules. Method allows reduction of environment pollution. Expanded clay aggregate characteristics: bulk density 500-550 kg/cu. m; compression strength in cylinder 18-25 kg/sq.cm; swelling interval (at annealing temperature of 1180 C) 30-50 C. EFFECT: higher efficiency.