SU1407981A1 - Mixture for briquetting chips - Google Patents

Abstract

The invention relates to foundry and can be used for smelting iron, invented to provide high metallurgical activity during the remelting, reduction of carbon loss and reduction in the cost of the smelted metal. Into the mixture for the briquetting of cast iron chips, the following components are introduced, wt%: pyrocarbon lime 2-4; welding Llyus AH 348-A 2-4; pig iron chips the rest. The presence of calcium oxide and carbon in pyrocarbon lime and their combined effect ensures an efficient, high-speed course of the reduction and carburization process of the remelting process. The introduction of flux AH 348-A ensures high strength of the briquette, compensates for the waste of silicon and manganese. 3 tab. (Oh cl

Description

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The invention is otgpsits to foundry and can be used for smelting iron.

The purpose of the invention is to ensure the remelting of high metallurgical activity of all components of the briquette, reduction of carbon loss and ruiraemie of the cost price of the molten metal.

The composition of the briquette provides for acidification and liquefaction of slag, carbon-mHsaHtre tuguna, expands the metallurgical capabilities of the lla processes) (ki due to the joint nostasis presence of Khchi in the briquette CeO, SLR and C.

Pyrocarbon lime is a byproduct of the hydrogen gas production process and consists of 30-35% carbon with a purity above 99% and 65-70% calcium oxide -

The apparent porosity of lime is 4-8%, it does not contain sulfur and phosphorus.

When pyrocarbon lime is introduced into the mixture, the minerals in its composition calcium oxide Caf) dissolve in the slag. The increase in CaO in the slag leads to a sharp decrease in viscosity.

slag, which in turn leads to the intensification of slag exchange processes between the donkey and the metal. Accordingly, the rate of reduction of Si and Mn by carbon from lime from slag oxides and the i-rx transition to cast iron is increased. The carbon dissolution in the pig iron is intensified due to the transition of its mechanical slag mixture (slag + carbon) into the metal.

Achieving a positive effect is due to the fact that both components of pyrocarbon lime (C and CaO) affect rshak and metal simultaneously in coBOKynfJocTH, which ensures an efficient, high-speed carburization and conversion processes of SiO, MpO and FeO,

In addition, the use of lyro-carbon lime, which is a by-product. The process of producing gaseous gas in the Orol (actually a production waste) makes the smelting process of pig iron economically viable and practical.

The use of briquettes consisting of pig-iron chips, pyrocarbon lime and welding flux AN348-A ensures the production of liquid slag of the following composition,%: CaO 40-55; C 25-32; CaF 1-2; SiOj 1018; thiO 8-15. R lacquer actively participates in the metal churches melting process.

Reducing the content of pyrocarbon lime in the briquette of less than 2% leads to the elimination of G and CaO, which in turn reduces slag deoxidation and reduction and the recovery of C, Si, Mn, F, e, as well as alloying and modifying elements from it.

An increase in the pyrolytic lime content of more than 4% results in a significant} first glut of pig iron with carbon (0.5% pyrocarbon lime increases the carbon content by 0.15% above the upper limit).

Welding flux AN348-L is included as a binder.

The chemical composition of the flux is given in abl. one .

Olius LN348-L both improves the strength of the briquette, compensates for the fatigue of Si and Mn, and, moreover, the CaO and Sar2 found in the welding flux contribute to the deoxidation and liquefaction of the slag.

When the welding flux contains less than 2% in the briquette, the impact and compression strength decreases sharply, which leads to an increase in carbon loss

With an increase in the amount of welding flux of more than 4%, the impact resistance does not change, and the compressive strength decreases.

The manufacture of briquettes is carried out as follows.

Pyrocarbon lime is crushed to a fraction of 3 mm and mixed with welding flux AN348-A and cast iron shavings. An electric current is passed through the resulting mixture, heated to 920-1000 ° C and compacted in a mold. As a result of heating, softening and a regular melting of chips and flux occur, and due to pressing - its compaction to the required strength.

Examples of the use of the proposed and known briquettes are presented in Table. 2

The tests are carried out in laboratory Hi.ix conditions for smelting iron in gas cupolas. The percent change in the carbon content of the iron from the calculated one, the content of iron oxides in the galaxy, the viscosity of the slag is determined.

As can be seen from the table. 2, the use of the proposed briquette for smelting iron can compensate for waste

carbon and deacidify. With this, the slag viscosity in the case of using the proposed briquette is almost within the same limits as in the known case.

Low carbon waste reduces the amount of expensive cast iron in the hawse, and the reduction of metals from oxides makes the smelting process more efficient and economical.

Table 3 shows the comparative data of the mechanical characteristics of the briquettes.

As can be seen from the table. .3 the strength of the proposed briquette is significantly higher than that of the known.

Thus, the smelting of cast iron using a briquette consisting of cast iron shavings, pyrocarbon lime and welding flux AN348-A allows the smelting process to be carried out with minimal burns and high efficiency.

Claims (1)

Invention Formula The mixture for briquetting chips, containing iron chips, carbon-containing material and a binder, characterized in that, in order to ensure high metallurgical activity during the remelting, reduce carbon loss and reduce the cost of the cost of melted metal, pyrocarbon lime is used as the carbon-containing material, and the welding flux AN348-A is used as a binder in the following ratio of 0 components , wt.%: Pyrocarbon lime 2-4 Welding flux AH348-A 2-4 Chugunna shavingsOstal Table 1 SiO MpO 1 CaO MgO CaF S P 40-44 34-38 Up to 4 8.5-9.5 3.7-4.3 Up to 5 , 0 0.15 0.12 T b l 2 Table 3 13.33 20.09 47, OL 45.46 61.25 59.78 1po; 1o. 1 table 2 Determined by the number of drops from a height of 2 m on a cast iron plate before the briquette is destroyed.