| 摘要 |
<p>Metal oxides or sulphides are reduced by a stream of carbon monoxide and hydrogen at a temperature above 800 DEG F. but below the melting point of the solid starting material or reduced product using gas produced by the reaction of a carbonaceous fuel at above 500 DEG F. with air at above 1000 DEG F. in an unpacked insulated reaction zone in such proportions that a temperature of 1800 DEG -2800 DEG F. is autogenously maintained in the reaction zone and the gas produced contains 5 volumes of carbon monoxide and hydrogen for each volume of carbon dioxide and water vapour. The fuel may be natural gas, liquid hydrocarbon coal or coke, the reaction time for the production of gas in the reaction zone being 3 to 10 seconds. Ores such as iron oxide or sulphide, or oxides of copper, nickel, chromium or manganese may be reduced in a fluidized bed, with counter-current gas flow, and a size grading of 100 microns to 1/8 inch in the case of iron ores. To complete the reduction relatively pure hydrogen, separated from part of the gas from the reactor, may be used in a final stage, the waste gas therefrom being recycled to the main ore reduction step.</p> |
