RU2549029C1 - Briquette for metallurgical treatment - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: briquette contains carbon containing substance and iron containing material including cast iron and steel shavings, iron oxides, lime dust and dust of ventilation system of electric arc furnaces as sources of iron oxide. Components of the briquette are contained in the following ratio, wt %: carbon containing substance - 10-15; lime dust - 5-10; iron containing material - rest, at that content of dust of the ventilation system of the electric arc furnaces is 10-15%. In the iron containing material quantity of the cast iron and steel shavings is in ratio 1:1.

EFFECT: reduced volume of slag during melting and increased quality of composition correction of the melted cast iron.

2 cl, 2 tbl, 1 ex

Description

The invention relates to the field of metallurgy, in particular, to the preparation of materials for smelting cast iron and steel, and can be used to produce molten iron and molten steel for the production of castings for various purposes.

A known method of briquetting metallurgical chips, including crushing it to obtain two fractions of chip elements of different lengths, mixing them, washing in an aqueous solution of labotomide, drying and compacting in a mold, characterized in that the lengths of the chip elements are chosen equal to 15-25 and 50- 60 mm and carry out mixing with weight ratios of 1: 1-1: 5, respectively, while drying is carried out at a temperature of 170-220 ° C (US Pat. RF No. 2146719, C22B 1/248, B22F 8/00, publ. 20.03.2000).

The briquettes obtained in this way are of unstable quality, in addition, the reduced lengths of the chip elements and their weight ratio do not provide their high adhesion, which affects the quality and strength of the briquettes.

Closest to the claimed is a briquette for metal redistribution, including iron-containing material containing cast iron and steel shavings, iron oxides of natural or industrial origin, a carbon-containing substance in the form of waste graphite electrodes and a binder, characterized in that the binder is made from a mixture of building cement and plasticizing air entrainment additives - adipic alkaline plasticizer (US Pat. RF No. 2228377, C22B 1/242, publ. 05/10/2004).

The use of binder cement and adipine alkaline plasticizer in the manufacturing process of briquettes is undesirable, because during smelting, these substances increase the amount of slag, while taking heat from the smelting and increasing the time spent by the smelter to download excess slag.

The objective of the invention is to obtain a simple briquette of sufficient mechanical strength to produce cast iron in a cupola.

The technical result is a reduction in the amount of slag during smelting and adjustment of the composition of cast iron due to the composition of the briquettes.

This is achieved by the fact that in the briquette for the production of cast iron in a cupola, consisting of carbon-containing substance and iron-containing material, including cast iron and steel shavings, iron oxides, lime dust and dust from the ventilation system of electric arc furnaces are introduced as a source of iron oxides in the following ratio of components in the briquette, % mass .:

carbon-containing substance - 10-15,

lime dust - 5-10,

iron-containing material - the rest,

when the dust content of the ventilation system of the melting furnaces as a source of iron oxides is 10-15% by weight of the iron-containing material.

In the iron-containing material, the amount of pig-iron and steel shavings was taken in a ratio of 1: 1 with the remaining materials in the briquette 1: (6.0-7.5), and in this case, iron oxides in the form of dust from the ventilation system from smelters are present in the iron-containing material 10-15% by weight of the substance contained.

As a carbon-containing substance, the briquette contains waste - a dusty fraction of graphite electrodes, and when the amount of sulfur contained in them is introduced, it will not affect the chemical composition of cast iron. When smelting cast iron in a gas cupola, the issue of adjusting the carbon content in cast iron is an urgent issue, which can be done by introducing carbon-containing material in the briquette into the charge.

The briquette contains calcareous dust, which favorably affects the smelting process and the chemical composition of the resulting cast iron, as in this case, the limestone necessary for the process of slag formation is introduced more evenly and uniformly.

An increase in the total content of non-metallic materials of over 40% is technically irrational, since the mechanical strength of the briquettes is noticeably reduced, which does not allow for their transportation to the consumer.

In the presence of iron oxides in briquettes - iron-containing material - in the form of dust from the ventilation system of electric arc furnaces and their application in a cupola, oxides are reduced to obtain metallic iron. The introduction of dust occurs along with the introduction of carbon-containing substances, lime dust and iron and steel shavings.

Briquettes are made by mechanical pressing on a MetallPress press due to the presence of cast iron and steel chips, which have plasticity, namely steel, due to which the components are coupled and the briquette acquires strength at least at the level of strength of cast iron embedded in cast iron chips.

To evaluate the proposed and well-known briquettes, a series of melts was carried out in a gas cupola.

Example

The components of the metallurgical briquette are fed into the press in the ratio indicated above, pressed; the output is a briquette of sufficient strength. Feeding to the cupola is carried out together with the metal charge. The briquette melts together with the mixture by increasing the temperature in the cupola. The controlled parameters in the composition of cast iron are shown in table 1.

Data on the composition of briquettes made according to the prototype and on the composition of the experimental batches of briquettes of the expected composition are shown in table 1.

The data of the spent swimming trunks with the use of briquettes of different composition in the charge are given in table 2.

These data indicate that the proposed briquette allows to ensure the stability of the process of smelting cast iron in a gas cupola, adjusting the carbon content in the melt, processing waste, and at the same time improving the quality of cast iron.

Table 1 Option The components of the briquettes, wt.% Mill scale Metal screening of vanadium production Cement PASCH Carbon Substances Lime dust Iron material Prototype briquette 10 fifty 10-18 01-0.9 5-35 - - Experienced briquettes 1st party - - - - 15.0 10.0 rest Experienced briquettes 2nd party - - - - 10.0 5,0 rest Experienced briquettes 3rd party - - - - 17.5 15.0 rest Experienced briquettes 4th party - - - - 7.0 3.0 rest

table 2 Option Controlled elements of cast iron,% Cast Iron Strength C Si Mn σ _in , kg / mm ² prototype The briquette worsens the cupola operation, reducing its productivity while increasing the amount of slag one 3.42 2.62 0.55 23.81 2 3.35 2.60 0.50 23.50 3 The briquette crumbles due to weak strength four 3.12 2,50 0.50 22.0

Claims (2)

1. Briquette for the production of cast iron in a cupola containing carbon-containing substance and iron-containing material, including cast-iron and steel shavings, iron oxides, characterized in that lime dust is introduced into it, and the dust of the ventilation system of electric arc furnaces as a source of iron oxides, in the following the ratio of components in the briquette, wt.%:
carbon-containing substance - 10-15,
lime dust - 5-10,
iron-containing material - the rest,
the dust content of the ventilation system of electric arc furnaces in it is 10-15%. 2. The briquette according to claim 1, characterized in that in the iron-containing material, the amount of iron and steel shavings is taken in a ratio of 1: 1.