Improvements in or relating to refractory mineral fiber and its method of production

728,354. Mineral wool. JOHNS-MANVILLE CORPORATION. Oct. 26, 1953, No. 29524/53. Class 56. A method of producing refractory mineral wool, which has good chemical and strength stability at temperatures at least as high as 2000 ‹ F. comprises fusing a mixture, preferably finely ground, of approximately 100 parts by weight of kyanite and 6-12 parts by weight of silica to a fluid consistency and fibreizing the fluid. The resulting wool has substantially the following composition: Al 2 O 3 51-55 per cent, SiO 2 43-47 per cent and the balance chiefly Fe 2 O 3 and TiO 2 , there being less than 0.5 per cent alkaline earth oxides. The wool is finely fibreized and easily cleaned of unfibreized shot by shaking or pneumatic cleaning procedure. The fibreizing operation is preferably carried out by steam blowing or rotating roll spinning method, the kyanite and silica being fused in an electric resistance furnace.