| 摘要 |
<p>754,182. Reduction of iron ores. TEXACO DEVELOPMENT CORPORATION. Sept. 7, 1954 [Sept. 14, 1953], No. 25907/54. Class 72. Finely divided iron oxide ores are reduced in a fluidised bed by passing hydrogen therethrough under the following conditions:- (a) hydrogen of at least 90 per cent purity is used ; (b) the temperature in the reduction zone is between 700‹ and 1050‹F.: (c) the hydrogen pressure is between 250 and 600 psig.: (d) the ratio of recycled gas to fresh gas is at least 5 : 1, water being removed from the exhaust gas by cooling before recycling. As shown, hydrogen is supplied to a heat exchanger 4 to raise its temperature to 300‹-550‹F. above that required in the reducing chamber 6 and iron oxide of particle size 10-3000 microns is added from the hopper 1 to the hydrogen stream. The reduced ore is removed from the reducing chamber 6 through a pipe 16 in a quiescent area 12 and melted, with the addition of lime in a furnace 20, e.g. an electric furnace. The speed of the hydrogen through the bed of ore may vary between 0À5 and 5À0 feet per second. The exhaust gas passes through a cyclone 10 to remove any entrained particles of ore and then cooled and scrubbed to reduce the water content to below 1 per cent. The gas for recycling is heated in a heat exchanger 29, brought to the required pressure by a compressor 37, heated to the required temperature in a heater 38, and added to the stream of fresh hydrogen entering the reducing chamber. A small quantity of recycle gas may be passed into the quiescent zone 12 to prevent agglomeration of the particles. The ore preferably has a silica content below 15 per cent.</p> |
