FIELD: metallurgy. SUBSTANCE: method includes fractionation of ore with the help of reducing gas into at least two fractions which have different distribution of grain sizes. Each fraction is reduced by means of reducing gas in separate fluidized bed. Reducing gas supports the first fluidized layer containing coarse-grained fraction, separates fine-grained fraction from coarse-grained one and is accelerated together with fine-grained fraction, and at pressure drop, it forms the second fluidized layer into which it is introduced continuously from below. Introduced additionally into this second fluidized bed is secondary reducing gas which is fed directly radially in symmetrical manner. Reduced ore is unloaded both from the first and also from the second fluidized beds. Plant for method embodiment has at least two reaction vessels located above each other. In this case, supplying pipeline of the first reaction vessel is located radially and symmetrically. Narrowing part of nozzle type for acceleration of reducing gas is made between device for discharge of gas of the first reaction vessel and hole for charging of finely divided ore and supplying of reducing gas of the second reaction vessel. The second reaction vessel is made with device for supply of secondary reducing gas. Device is located radially and symmetrically in vessel lower part and made in the form of gas-distributing bottom. EFFECT: uniform and constant degree of metal formation with optimal use of reducing gas and minimization o its quantity. 12 cl, 2 dwg
Authors
Dates
1999-06-10—Published
1996-03-11—Filed