Societe Nationale De L'amiante

Other

Hydro-quebec

Université De Sherbrooke

Societe Nationale De Liamiante

Jean M Lalancette

Jean P Chevalier-Bultel

Luc Desrosiers

Germain Belanger

Jean P Drolet

Jacques Dunnigan

Hugues Hamelin

Claude Ostiguy

Normand Labonte

There is provided a method for preparing cured moulded article of a predetermined density of from 1.66 to 9.0 which comprises selecting the resin and determining it % weight loss and % porosity under the curing conditions for the selected resin, then selecting a high density filler and a low density filler and resolving the equation: ##EQU1## wherein K is the desired density of the end product and has a value of from 1.66 to 9.0; HD is the density of the selected high density substantially water-insoluble material and has a value of above 3.2; ID is the density of the selected medium density substantially water-insoluble material and has a value of from 1.5 to 3.2; R is the density of the cured binding resin and has a value between 0.8 to 1.5; A is the percentage by weight of the selected high density filler having the density HD and has a value of from 10 to 90%; B is the percentage by weight of the selected medium density filler having the density ID and has a value of from 0 to 86%; C is the percentage by weight of the selected binding resin having the density R and has a value of from 4 to 70%; and Y is the porosity of the end product expressed in % of the volume of the moulded object.

Moulded compounding mixtures of adjustable density

There is disclosed a process for the destruction of toxic organic halogenated substances which comprises treating in a reaction chamber under a reductive atmosphere and at a temperature of from 1000.degree. to 1600.degree. C. a mixture of a toxic organic halogenated substance, carbon and a carbonate or bicarbonate of an alkali metal or of an alkaline earth metal whereby vapors of the alkali or alkaline earth metal are generated 'in situ' to cause total degradation of the toxic organic halogenated substance into alkali or alkaline earth metal halide and carbon with the production of carbon monoxide which is subsequently oxidized into carbon dioxide.

Process for the destruction of toxic organic products

There is disclosed a granular product suitable for use as foundry sands and obtained from asbestos tailings calcined at a temperature of from 1250.degree. to 1450.degree. C., said asbestos tailings having an MgO:SiO.sub.2 ratio greater than 1.0, the granules constituting the granular product being characterized by having a thermal expansion at 1000.degree. C. of not more than 1.0% and a particle size of between -20 to +200 mesh (Tyler), the granules being further characterized by being made up mainly of particles of enstatite bonded by gruenerite and fayalite, and substantially unreactive to basic oxides present in the cast metal.

Foundry sands derived from serpentine and foundry molds derived therefrom

There is provided a sintered angular shape granular sandblasting material obtained by the calcination of asbestos tailings at a temperature of from 1300.degree. C. to 1450.degree. C., said asbestos tailings being characterized by having a MgO:SiO.sub.2 ratio lower than 1.0, the granular sandblasting material being characterized by a cold compression mechanical strength of from 10 to 160 MPa, by a granulometry of -40 to +150 mesh (Tyler), and by being substantially free of dust.

Calcined serpentine useful as sandblasting agent

The invention disclosed relates to the manufacture of compressed fertilizer pellets for dispensing sulfur and magnesium and at least one of the essential elements selected from nitrogen, potassium and phosphorous, the pellets are formed by compressing a compound containing at least one of the essential elements with a hydrated magnesium sulfate containing at least four moles of water of hydration.

Fertilizers pelletized with hydrated sulfates

A light colored and asbestos free granular material of the invention is suitable for use as lightweight fillers in plastics and is derived from asbestos tailings wherein the MgO:SiO.sub.2 ratio is at least 1.0, said granular material comprising particles consisting of a mixture of enstatite, forsterite and silica having a particle size of from -400 to -10 mesh, said particles being coated with a silicate bonded layer of calcium oxide or magnesium oxide or mixtures thereof, said particles being further characterized by having a density of from 17 to 25 lb/ft.sup.3 and having a degree of whiteness within the range of from 50 to 60 when measured by the ASTM Procedure No. E-97-77.

Light colored and low density mineral filler from magnesium silicate

There is provided a process for replacing the magnesium oxide portion of a nature magnesium silicate with sodium oxide thereby to form sodium silicate which comprises melting a natural magnesium silicate and sodium carbonate at a temperature of from 1100.degree. to 1350.degree. C. until a clear melt is obtained, the molar ratio of sodium oxide derived from the sodium carbonate per mole of silica contained in the natural magnesium silicate being from 4:1 to 7:1, quenching and extracting said clear melt with water and separating the insoluble magnesium oxide from the solution containing predominantly sodium silicate and sodium hydroxide.

Production of magnesium oxide from magnesium silicates by basic

There is provided an improved non-woven fibrous felt material made up of fibers, partially fibrous agglomerates of forsterite, enstatite and silica as filler and an organic binder. The improved felt material possesses increased hot tensile strength over felt material made from non-calcined asbestos tailings or inert inorganic fillers.

Calcined serpentine as inorganic charge in sheet materials

There is disclosed chemically modified chrysotile asbestos fibers, more particularly phosphated asbestos fibers containing from 0.5 to 5% by weight of phosphate groups and heat treated phosphated asbestos fibers, both of which have an infrared spectrum which exhibits substantially no absorption within the range of 954-1080 cm.sup.-1. The novel phosphated asbestos fibers are characterized by reduced haemolytic and cytotoxic activities.

Phosphated asbestos fibers

The addition of an excess of asbestos tailings in the course of the extraction of magnesium from asbestos tailings by digestion with an acid greatly facilitates the elimination of silica and other impurities by filtration of the resulting reaction mixture. The improvement reduces the filtration time and the filtration leaves a cake which is much easier to dispose.

Filtering of precipitating silica

There is provided a molded shaped structure made by molding the reaction product of an organic resin and a modified magnesium silicate obtained by calcining chrysotile asbestos tailings. The new product is characterized by the absence of any fibers.

Growing community of inventors

Sherbrooke, Canada

Jean M Lalancette