Verfahren fuer die Eisengewinnung mit Hilfe von Kernenergie

摘要

Iron ores are reduced with solid, liquid or gaseous reducing agents, e.g. coal, coke, anthracite, charcoal, petroleum oil, CO and/or H2 or natural gas, preferably in a continuous shaft kiln, by transferring the heat evolved in a nuclear reactor from a coolant circulating therethrough to the reaction material, preferably a pelletized fine-grained mixture of iron ore e.g. haematite and coal or coke. A secondary heating vehicle, such as liquid metal or alloy e.g. Na or Na-K or a circulating gas mixture of CO and CO2 may be used to heat the mixture. The reaction material may be fluidized in the reduction chamber by agitation, the reaction gas evolved or the injection of an auxiliary gas such as a CO/CO2 mixture. As shown, the reduction may be performed in two stages: partial reduction of briquettes of ore and coal, prepared in system 11 and pre-heated in chamber 13, to reduction levels in which 40-75% of the oxygen is removed in an ore/coal reactor 14, then final reduction by reducing gases such as CO and H2 to remove 85-95% of the oxygen in the untreated ore in an ore/gas reactor 15, both reactors being heated by a fluid heating medium circulating in a circuit 5 through a heat exchanger 2 heated by the nuclear reactor coolant in a circuit 4. The resulting sponge iron may be cooled in a cooling chamber 16 to yield heat in countercurrent to a fresh charge of briquettes by means of a circuit 17 in which may circulate liquid Pb or Na or alloys thereof, or CO2. Excess coal (22) may be removed from the sponge iron (21) in a magnetic separator 19 and from ash (23) in an electrostatic separator 20 and returned to fresh ore (24). Gases evolved in the first reduction stage in reactor 14 may be removed, have their CO2 and H2O contents removed during cooling and cleaning in systems 26-28, and be returned pre-heated (through heat exchanger 26) to the reactor 15.