SU48405A1 - Method for the desulfurization of iron during smelting in a cupola with the introduction of manganese slag in the mixture - Google Patents

Description

As is known, the fight against sulfur in iron casting is one of the pressing issues in many industries, in particular, in the automotive industry). According to the proposed method for the desulfurization of cast iron during smelting in a cupola, based on the well-known property of manganese, the sulfur is absorbed; manganese (green blast furnace) slag is introduced into the mixture instead of the flux, loading it onto a coke pile (under a pig-iron ear). By using this method, it is meant to allow more sulphurous (defective) cast iron to be found in the area of foundry and, at the same time, to achieve economy, to lead the smelting process on sulphurous coke. Indeed, manganese in the form of MnO oxide in green slag gives the following decomposition decomposition with sulfur iron: MnO - {- FeS FeO-f-MnS, and the resulting sulfur manganese goes into slag, thus desulfurizing cast iron.

Due to the low temperature of the B cupola, the process of oxidation (rather than reduction) takes place, and therefore manganese oxide, which is in green slag, is not reduced.

in Mp and, thus, does not pass into cast iron, but only reacts with sulphurous iron, desulfurize cast iron and transition into sulphurous manganese, which passes into slag.

The results of work in a cupola melting in which was conducted on green slag are summarized below:

. a) Analysis of cast iron, taken (in the cupola in proi.).

Si - 2.77; Mp 0.67: S - 0.131 Si - 2.75; Mp 0.65; .146

b) The composition of the charge.

iron ..... 400 kg of green slag. Ab t lgg

c) L I; t e (in the pro.).

Si. 1.91; Mp 6.67; S 0.06 Si 1:71; JVSn 0.60; S - 0.7I

Ii. a) Analysis of 1 h, ETHER i: Bai-wound (in percent).

Si - 2.82: Mn O 5S; S 0.096 Si 2.09; Mti. 0.56; S 0,090

b) Analysis of green slag to percents.).

SiCj 29.60; AlgOs 12.52; CaO: - 22.76; MpO - 29.75; Mp FeO 1.40; S 1.80

c) ./1 and t with (in percent).

Si - 2.06; MP: 0.51; S 0.041 Si, 09; Mp 0,5S; S 0,058

d) Slag analysis (in percent) SiOs -: 40.08; AlaOg. 12, SO; CaO 21.68; MnO - 16.18; Fe ---. 3.95 Mn ::: - 12.45; FeO 5.09; , 05; , 52

As is known, the sulphide casting melts at a relatively low temperature, and the melts are very thick. The sulphurous cast irons in the molten state poorly fill the molds, when they are cooled, they produce shells, and the surface of the castings gets a rough look. In addition, during the cooling of the cast iron sulphide castings often crack. When conducting the smelting process on a green slag cupola, all these drawbacks are eliminated, and the amount of sulfur is reduced, on average, by almost half, despite the fact that experimental smelting was carried out on coke with a sulfur content of 2.207. iron, sulfurous, e iron.

The melted sulfur iron in the green slag cupola gives a low-sulfur cast that fills the mold well. When the iron is filled, slag is injected into the cupola, then coke, and when the smelting process is conducted in the hearth, everyone keeps a layer of molten slag (slag pad) so that the molten iron, the outlet of the cupola, passes through the layer of plaglu, playing: for the desulfurization of pig iron.

The subject matter of the invention.

A process for the desulfurization of pig iron, when smelted in a cupola, with the introduction of manganese slag (for example, a green blast furnace) into the mixture, characterized in that the manganese slag is introduced into the mixture instead of flux and loaded onto a coke pile under a pig iron ear and a layer of liquid is constantly maintained in the furnace. slag (slag bed) of sufficient thickness to desulfurize the molten pig iron as it passes through the layer of liquid slag.