METHOD FOR PRODUCING CONTINUOUS FIBRES FROM MELT OF BASALT ROCKS Russian patent published in 1998 - IPC

FIELD: production of chemically stable, high-temperature filters, fabrics and structural articles. SUBSTANCE: basalt rock having particle size 5-15 mm and acidity module 4.7-6.5 is melted down, without adding any corrective additive, in furnace at temperature 1500-1600 C, in oxidizing medium. As melt temperature rises up to 1600 C, degree of its amorphism increases. Fe203-to-FeO weight ratio in melt is at least 1.2, while sum total of iron oxides is equal to 8-12%. Fibres are produced at temperature 1310-1370 C, melt viscosity 12-85 Pa.s, ration being . Lower temperature limit of temperature range, within fibres are produced, is at least 70 C, upper crystallization temperature limit being at most 1250 C. EFFECT: higher efficiency. 3 tbl