Les Sables Olimag, Inc.

Her Majesty the Queen in Right of Canada as Represented by the Minister of Natural Resources

Her Majesty the Queen in Right of Canada, as Represented by the Minister

Jay Aota

Yvan Huard

Gilles Mathieu

Lucie Morin

Shaped bodies containing particulate iron materials, such as cast pellets, briquettes and the like, with sufficient strength to withstand temperatures of up to at least 1000&deg; C. can be obtained by using a fully hydrated high-alumina cement as the binder. The strength of the pellets at elevated temperatures can be further enhanced by adding small amounts of bentonite, silica fume or other suitable supplementary cementing materials, and super plasticizer. The iron particulate materials, typically having a size range of from about 0.01 mm to 6 mm, include ore fines, sinter fines, BOF and EAF dusts, mill scale, and the like. Powdered carbonaceous material, such as ground coal or coke, may also be added to the pellets. The shaped bodies are suitable for use in blast furnaces, basic oxygen furnaces, and in DRI processes.

Cold bonded iron particulate pellets

A process in which a calcining step is used to provide a stable clinker containing the EAF dust. The clinker meets all of the applicable leaching standards. It also appears to be possible to use largely oxidic wastes from other processes, such as zinc electroplating residues, and the largely oxidic residues from refuse fuelled power generators. In this low temperature vitrification process a powder composition containing from 20% to 63% by weight waste material, from 30% to 73% by weight silica, and from 7% to 30% by weight alumina, is wetted to form a homogenous mass. The mass is fired in a furnace for a sufficient time and to a temperature of less than about 1,300.degree. C. to cause vitrification; and the vitrified product is recovered as a fired clinker. The clinker, after crushing, can be used as a road aggregate, in tarmac mixes, or after crushing to a suitably small powder, in the making of bricks and tiles having good abrasion and heat resistance.

EAF dust treatment

Compositions for refractory materials and methods for providing the compositions are described. A synthetic forsterite-rich refractory sand composition includes a mixture. The mixture includes: a) a carbon bridging agent, the carbon bridging agent being present in the mixture in a proportion of from approximately 5 to approximately 15 percent by weight of the mixture; and b) a synthetic forsterite-rich sand, the synthetic forsterite-rich sand being free-flowing, having a MgO:SiO.sub.2 weight ratio of at least approximately 1.2, a specific gravity of approximately 3 g/cm.sup.3, a void volume of less than approximately 50 percent by volume of the synthetic forsterite-rich sand, and a fusion point of at least approximately 1610.degree. C., wherein i) at least approximately 50 percent by weight of the synthetic forsterite-rich sand is forsterite, and ii) from approximately 3 to approximately 27 percent by weight of the synthetic forsterite-rich sand is maghemite. The compositions and methods provide advantages in that the resulting refractory product have suitable characteristics with respect to size distribution, packing ability, thermal resistance and sintering properties for utilization as ladle sand or for similar refractory uses.

Refractory sand composition

A synthetic forsterite-rich refractory sand composition for use as a taphole nozzle refractory sand for a sliding gate system of a steel ladle, the synthetic forsterite-rich sand composition including a mixture, the mixture including: a) a carbon bridging agent, the carbon bridging agent being present in the mixture in a proportion of from 5 to 15 percent by weight of the mixture; and b) a synthetic forsterite-rich sand, the synthetic forsterite-rich sand being free-flowing, having a MgO:SiO.sub.2 weight ratio of at least 1.2, a specific gravity of approximately 3 g/cm.sup.3, a void volume of less than approximately 50 percent by volume of the synthetic forsterite-rich refractory sand, and a fusion point of at least 1610.degree. C. At least 50 percent by weight of the synthetic forsterite-rich sand is forsterite; and from 8 to 27 percent by weight of the synthetic forsterite-rich sand is maghemite.

Forsterite-rich refractory sand composition

A process for obtaining a synthetic refractory sand for use in steelmaking, said synthetic refractory sand being free-flowing, comprising at least 50% forsterite, having semi-angular and irregularly shaped grains, lenses and flat grains, a specific gravity of approximately 3 g/cm.sup.3, a void volume of less than approximately 50%, a coefficient of thermal expansion of approximately 1.09.times.10.sup.-5 and a fusion point of at least 1610.degree. C. including the steps of: (a) agglomerating a mixture comprising a particulate starting material selected from the group consisting of serpentine-containing asbestos tailings and an enstatite-containing product produced by calcining serpentine-containing asbestos tailings and from 10% to 25%, based on the total weight of mixture, of magnesium oxides or precursors of magnesium oxides with an aqueous binder solution to obtain agglomerates of said mixture; (b) calcining said agglomerates at a temperature of from 1200.degree. C. to 1500.degree. C. for from 1 to 2 hours; (c) recovering said synthetic refractory sand from the calcined agglomerates; and (d) crushing said synthetic refractory sand to a desired mesh size.

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Kanata, Canada

Jay Aota