Direct reduction of metallic oxides
AssigneeHydrocarbon Research, Inc.
InventorWilliam Volk
Life of this patent
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Abstract
The capacity and effectiveness of a fluidized multi-bed process for the direct reduction of broad size-range metallic oxides, such as ion oxide particles, can be materially improved by feeding the large-size particles into the uppermost zone and the fine-particle material such as bag dust to the lowest zone of a multiple bed reducer. The larger particles in the upper zones tend to restrain the fine particles from being carried out of the reducer by upwardly flowing reducing gas. In the lower zone location, complete reduction of the fine oxide particles is much more effective, as the reaction is initiated by the fresh reducing gas, which is normally high purity hydrogen.
Claims7
In a method for the direct reduction of metallic oxide particles in a multiple zone reducer using upflowing hydrogen to maintain the particles of oxides in a fluidized condition at a temperature from about 700.degree.F to about 1000.degree.F and a pressure from about 200 to about 600 psig, and in which a part of the oxides of coarse size range are introduced to the uppermost zone and from which zone the particles pass successively downward to a lower zone after being appropriately contacted with the upflowing hydrogen and the reduced metal particles are removed, the improvement which comprises:
- a. separately feeding finer size metal oxide particles directly to a lower zone using cold hydrogen gas as the transport medium for said finer size metal oxides;
- b. initially contacting the finer oxide particles with high purity hydrogen in said lower zone to accomplish a substantially short and complete reduction within said zone;
- c. passing the hydrogen from the lowermost zone to an upper zone;
- and
- d. withdrawing the reduced fine oxide along with said reduced metal particles from the lowermost zone.
Dependencies are inferred from the claim text.