There is provided a shaped three-dimensional calcined phosphate-bonded magnesium silicate comprising the shaped reaction product of phosphoric acid with a natural magnesium silicate selected from uncalcined magnesium silicate and magnesium silicate tailings which have been calcined at a temperature of from 800 to 1300 DEG C, provided that the reaction product of phosphoric acid with uncalcined magnesium silicate has been calcined at a temperature of from 800 to 1100 DEG C while shaping, the selected magnesium silicate having an aspect ratio l /d/= 500 wherein l is the average length and d is the average diameter of the selected natural magnesium silicate particle. The products are useful as insulating products, firewall and casting products and dielectric products depending on the amount of each starting material used and are furhter characterized by being asbestos-free.
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