| 摘要 |
<p>FIELD: ferrous metallurgy. SUBSTANCE: synthesis gas is combined with blast-furnace gas evolved in direct reduction of an iron oxide-containing material, and combined gas is used as reducing gas in the latter process. To diminish or exclude metal dusting, content of water in reducing gas is maintained equal to 1-2%, advantageously 1.5%, by removing carbon dioxide from one portion of blast-furnace gas before using of blast-furnace gas as reducing gas. Purified blast-furnace gas is mixed with synthesis gas, temperature of the mixture is adjusted to specified value and mixture is simultaneously saturated with water through direct spraying. Thereafter, mixture is heated to a temperature exceeding that of saturation by adding non-purified blast-furnace gas and then is used as reducing gas. In another version of invention, prior to be used as reducing gas, gas is additionally set free of mist. One more version provides for regulation of desired content of water by varying temperature of carbon dioxide scrubber. Plant comprises at least one reactor to receive and reduce iron-containing material, carbon dioxide scrubber, gas heater, and direct-type cooler in which gas is directly cooled or heated by sprinkling water (colder or more hot than reducing gas). In the second version, formation of sulfuric acid as a result of condensation of saturated reducing gas is prevented by passing gas through mist separator. EFFECT: excluded or diminished metal dusting due to increased carbon monoxide content in gas by simple and efficient method and reduced power consumption. 18 cl, 2 dwg, 3 tbl1</p> |
