Abstract: A process for the manufacture of industrial cordierite ceramic units containing from 45 to 68% by weight of silica 16 to 37% by weight of magnesia and 12 to 45% by weight of alumina which comprises (a) mixing from 15 to 60% by weight of the non-magnetic fraction of asbestos tailings having a MgO:SiO.sub.2 of from 0.8 to 1.25 with 40 to 85% of a kaolin clay by weight and 0 to 10% of alumina; (b) shaping said mixture in green unit forms; (c) curing said units at room temperature for 24 h then at 110.degree. C. for 24 h; (d) firing said cured units at a temperature of from 1350 1400.degree. C.

Abstract: There is provided a process for agglomerating volatilized silica in the form of grains by wetting same with from about 10 to about 35% by weight of an alkali or alkaline earth metal oxide solution in water, said agglomerated volatilized silica having a densification factor of 1.7 to 2.5 (when oven-dried) and a dry bulk density of from about 500 to 775 kg/m.sup.3. These agglomerated volatilized silica grains can be used to replace advantageously up to 50%, and in some cases more, by weight of Portland cement in the manufacture of concrete.

Abstract: There is disclosed a compacted unit of metallurgical grade granular material selected from silicon and ferrosilicon comprising a compressed homogeneous mixture of a fine powder of a silicon material selected from the group consisting of silicon and ferrosilicon, said silicon material being finer than 160 .mu.m, from 2 to about 5% by weight of the silicon material of sodium or calcium bentonite and from 2 to about 5% by weight of the silicon material of sodium or calcium lignosulfonate. The novel compacted units are useful for use in industrial processes requiring substantially pure silicon or ferrosilicon.

Abstract: There is disclosed a dry granular calcined magnetic fraction obtained from chrysotile asbestos tailings comprising as its main constituents from 25 to 43% MgO, from 25 to 43% SiO.sub.2, from 15 to 40% iron expressed as Fe.sub.2 O.sub.3, and an MgO/SiO.sub.2 ratio of from 0.8:1 to 1.3:1, said granular material passing a 4 mesh sieve. The novel product is useful for the preparation of heat storage cores and refractory bricks for glass tank checkers or blast furnace stoves.

Abstract: There is provided a novel harzburgite of the formula Py.sub.x Ol.sub.(1-x) where x is a decimal number of from 0.001 to 0.4, Py is an abbreviation for pyroxene, and Ol is an abbreviation for olivine having a total iron oxide content of less than 5% which is obtained by calcining a demagnetized fraction from a magnetite-containing serpentinite. The novel harzburgite is useful for preparing refractories.