Producing pig-iron, esp. sponge iron from fine ore - with initial division of the ore into fine and coarse fractions and use of mechanical means to break up clusters forming in fluid-bed reactors

摘要

The process for producing pig iron from fine ore involves reduction and calcination of iron ores in several successive fluid-bed reactors. It is characterised by the following: (a) ore is divided into fine and coarse fractions; (b) the coarse fraction is reduced up to 60% in the first fluid-bed reactor; (c) the fine fraction is fed as an addition into a subsequent reactor; and (d) material in subsequent reactors is subjected to mechanical mixing and cluster-breaking action. The first reactor is used also as a wind sifter to separate the material into fine and coarse fractions, with the fine fraction taken away be the waste gas. The gas outlet (72a) of the first reactor (12a) is connected to a cyclone (74) whose dust outlet is connected to a subsequent reactor (12c). At least the reactors (12b, 12c) following the first one are provided with cluster breakers (94). There are at least three cluster breakers (94) in the form of water-cooled toothed rolls in each reactor (12b, 12c). These rolls are set for a maximum permissible cluster size of 150 mm. USE/ADVANTAGE - Pig-iron is produced without preliminary preparation of the ore, thus eliminating the need for pelleting and sintering plants.