Université De Sherbrooke

Universitéde Montreal

Societe Nationale De L'amionte

Pierre C Aitcin

Philippe Pinsonneault

Roland Fortin

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.

Process for manufacturing cordierite compositions

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.

Agglomerated volatilized silica dust

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.

Briquettes of silicon and ferrosilicon dust

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.

Dry granular calcined magnetic fraction obtained from chrysotile

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.

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Sherbrooke, Canada

Pierre C Aitcin