| 摘要 |
1307869 Reducing iron oxide METALLGESELLSCHAFT A G 7 Aug 1970 [21 Aug 1969] 38262/70 Heading C7D Iron oxide is reduced in a rotary kiln provided with shell tubes by treatment with a reducing agent comprising highly reactive coal which disintegrates at the kiln temperature and is distributed over the length of the reduction zone on the surface of the charge bed, co-currently with the flow of kiln gases, below the melting point of the charge. The throughput is adjusted so that the carbon content of the matter discharged from the kiln is below 1À5% w/n based on the charge of iron oxide-containing material. The reducing agent may be brown coal; the ash may be basic, and serve, at least partly, as a desulphurizing agent. Other sulphur-combining materials, such as limestone or dolomite, may be charged or blown into the kiln. Ash may be discharged by entrainment in the exhaust gases. Air may be supplied to each part of the kiln in amount sufficient to produce the reduction heat by combustion of the volatilized constituents of the coal, but not so as to cause oxidation of the iron oxides. Reference has been directed by the Comptroller to Specification 1222123. |
