Method for the commercial production of iron
AssigneeIron Mineral Benefication Ser4vices (Proprietary) Limited
InventorsGerard Pretorius, Derek Roy Oldnall
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Abstract
A method for the production of iron from an iron oxide-containing material includes contacting an iron oxide-containing material with a particle size distribution range with a ∂90 of less than 2 mm, with a carbon-containing material with a particle size distribution range with a ∂90 of less than 6 mm, in a commercial scale reactor at a temperature of between 900° C. and 1200° C. for a contact time sufficient to reduce the iron oxide to iron.
Claims18
A method for the production of iron from an iron oxide-containing material, the method including contacting an iron oxide-containing material with a particle size distribution range with a ∂90 of less than 2 mm, with a carbon-containing material with a particle size distribution range with a ∂90 of less than 6 mm, in a commercial scale reactor at a temperature of between 900° C. and 1200° C. for a contact time sufficient to reduce the iron oxide to iron.
The method as claimed in any of the preceding claims, in which the carbon-containing material has a ∂90 of less than 2 mm.
The method as claimed in any of the preceding claims, in which the contact time is between 30 minutes and 360 minutes.
The method as claimed in any of the preceding claims, in which the carbon-containing material is de-volatilised coal fines.
The method as claimed in any of the preceding claims, in which the temperature in the reactor is between 1000° C. and 1100° C.
The method as claimed in any of the preceding claims, which includes heating the reactor using an external heat source.
The method as claimed in any of the preceding claims, in which contacting the iron oxide-containing material with the carbon-containing material includes feeding pre-determined quantities of said materials into a rotating cylindrical reactor or rotary kiln and setting the rate of rotation and the angle of the reactor so that the residence time of the material in the reactor is sufficient to reduce substantially all of the iron oxide to iron.
The method as claimed in any of the preceding claims, which includes preventing ingress of air into the reactor.
The method as claimed in any of the preceding claims, in which the feed rates of the iron oxide-containing material and the carbon-containing material and the operating temperature of the reactor are selected so that a superficial gas flow rate through the reactor caused by the release of gases resulting from the reduction is less than 2 ms−1.
The method as claimed in any of the preceding claims, which includes controlling iron oxide-containing material and carbon-containing material feed rate, reactor temperature and gas withdrawal rate from the reactor to achieve a substantially steady state concentration of carbon monoxide in the reactor.
The method as claimed in any of the preceding claims, which includes contacting the iron oxide-containing material with a slight excess of the carbon-containing material, magnetically separating product iron from excess carbon-containing material, and melting the iron product, producing mild steel with a purity in excess of 99% by mass.
A reactor assembly suitable for use in the commercial production of iron from an iron oxide-containing material which has a particle size distribution range with a ∂90 of less than about 2 mm by contacting the material with a carbon-containing material which has a particle size distribution range with a ∂90 of less than about 6 mm at an elevated temperature, the reactor assembly including a generally cylindrical reactor with an inlet and an outlet mounted for rotation about a longitudinal axis thereof, heating means for heating the reactor to a temperature of between about 900° C. and 1200° C. and mounting means for mounting the assembly on a vehicle.
Dependencies are inferred from the claim text.