Method for coating iron-bearing particles to be processed in a direct reduction process
AssigneeHylsa S.A. de C.V.
InventorsJorge D. Berrun-Castanon, Maria T. Guerra-Reyes, Leopoldo I. Ruiz-Leal
Life of this patent
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Abstract
At least a percentage of iron ore pellets and the like for use in a direct reduction process for the production of sponge iron are coated with a thin porous coating of Portland cement to counteract tendency to aggregate. This is accomplished by method and apparatus that mixes water and cement powder at the point of delivery in a manner such that no pumps are subjected to a wet cement slurry. The slurry is mixed and maintained in suspension by air agitation in a bin and then flowed through a bin discharge pipe and sprayed therefrom onto a passing layer of pellets in a controlled manner by regulated air injection into the discharage pipe.
Claims7
Method of coating iron-bearing particles with a water-insoluble powdery material, said method comprising:
- introducing said powdery material and water in predetermined quantities into a container to form a suspension;
- mixing and maintaining under agitation said suspension by injecting air into said container;
- and
- spraying said suspension from a discharge point of said container, said discharge point being proximate said iron-bearing particles, said spraying forming a coating on at least part of some of particles, and while spraying, injecting a stream of air into said suspension proximate, but upstream of said discharge point so as to regulate the amount of said suspension flowing out of the discharge point and onto the particles.
Method of coating iron-bearing particles with a powdery material non-soluble in water comprising:
- introducing said powdery material and water in predetermined quantities into a bin;
- injecting air into said bin to cause said powdery material and water to be thoroughly mixed to form a suspension and maintaining said suspension under agitation by means of said injected air;
- and
- injecting a stream of air into a narrow discharge pipe of said bin for regulating the amount of said suspension flowing out of said bin through said pipe and for spraying said suspension over said iron-bearing particles.
Dependencies are inferred from the claim text.