US 4,627,601 AGranted

Installation for the production of steel by pre-smelting of pig iron

AssigneeIrsid

InventorsAristide Berthet, Guy Denier

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Abstract

Installation according to the invention comprising a desilication and dephosphorization stage (A), followed by a decarburization stage and in which the pig iron to be pre-smelted is intended to form a bath whose free surface is maintained at a predetermined level (N.sub.1). The dephosphorization comprises a reactor (1) comprising means (5, 6, 8) respectively for introducing the pig iron to be pre-smelted, for adding desilication and dephosphorization agents, and for creating an oxidizing atmosphere, as well as rabbling means (9). It also comprises a decanter (2) separated from the reactor (1) by a partition (3) having an opening (4) below the level (N.sub.1) and whose upper end is above the latter. The decanter comprises an immersed outlet opening (10) connected to the decarburization stage and an overflow (12) for evacuating the slag. The slag formed in the reactor (1) flows out in the decanter (2), overflows above the partition (3), and moves toward the overflow (12) which evacuated it.

Claims8

Dependent claims

Installation for the production of steel by pre-smelting of pig iron comprising a stage of desilication and of dephosphorization followed by a decarburization stage, wherein said desilication and dephosphorization stage is constituted by at least one closed unit comprising

(a) a first reactor (1) in which the pig iron to be pre-smelted forms a bath whose surface is maintained at a first predetermined level (N.sub.1), said reactor having
(i) an upper part above said first predetermined level (N.sub.1), provided with means (5) for introducing the pig iron to be pre-smelted, means (6) for introducing agents for oxidizing silicon and phosphorus, agents for forming a desilication and dephosphorization slag, and means (8) for creating an oxidizing atmosphere above said bath;
and
(ii) a lower part, below said first predetermined level (N.sub.1), provided with means (9) for stirring of the metallic bath;
and
(b) a decanter (2) separated from said first reactor (1) by a partition (3) comprising a communication opening (4) below said first predetermined level (N.sub.1) and whose free upper end, extending above said first predetermined level (N.sub.1) constitutes a sill encircling the slag formed in the reactor, this decanter comprising
(i) an outlet opening (10) located below said first predetermined level (N.sub.1) and communicating with a connecting conduit (11) to permit the circulation of a flow of desilicated and dephosphorized pig iron toward said decarburization stage;
and
(ii) an overflow (12) located above said first predetermined level (N.sub.1) for evacuating the decanted desilication and dephosphorization slag coming from said first reactor (1) to the exterior.

6 more elements

Dependencies are inferred from the claim text.