METHOD AND EQUIPMENT FOR PRODUCTION OF EXPANDED VERMICULITE Russian patent published in 1999 - IPC

FIELD: construction materials industry. SUBSTANCE: method and equipment can be used for production of expanded vermiculite directly from non-concentrated ore with content of waste rock mass from 15 to 85%. According to method, raw material before delivery into main calcining passage of kiln is partly dried and heated to 80-120 deg. in additional drying and heating passage by means of exhaust gases taken after main calcining passage. Heating of raw material in both passages of kiln is initially performed in direct-flow process when material is in suspended pulverized condition, and then in counter-flow process when material naturally flows down over inclined surface of material bed. Heating of vermiculite is performed at temperature of 300-600 deg. to 800-1000 deg. Application of aforesaid method and equipment allows for enhancing quality and output of expanded material. EFFECT: higher efficiency. 2 cl, 2 dwg, 2 tbl