Mineral fibres degradable in physiological medium.

THE PRESENT INVENTION REFERS TO COMPOSITIONS OF MINERAL FIBERS SUSCEPTIBLE TO DEGRADE ON CONTACT WITH A PHYSIOLOGICAL ENVIRONMENT. SOME ADVANTAGEOUS COMPOSITIONS INCLUDE THE FOLLOWING CONSTITUENTS, ACCORDING TO DEFINED WEIGHT PROPORTIONS: SIO SUB 2 37 TO 58% AL SUB 2 OR SUB 3 4 TO 14% CAO 7 TO 40% MGO 4 TO 16% P SUB 2 OR SUB 5 1 A 10% FE SUB 2 OR SUB 3 0 TO 15% (TOTAL IRON EXPRESSED IN THIS FORM) THE SUM CAO + MGO + FE SUB 2 OR SUB 3 REMAINS HIGHER THAN 25% AS WELL AS NA SUB 2 OYK SUB 2 O OXIDES, WHOSE SUM OF PERCENTAGES REMAINS LESS THAN 7%.