SU1477755A1 - Brick for iron-casting - Google Patents

Abstract

The invention relates to the field of metallurgy, specifically to the preparation of charge materials for smelting iron, and can be used in the production of liquid iron for the manufacture of castings for various purposes. The aim of the invention is to reduce the cost of the charge, increase flux and strength. In the briquette on the basis of ferrous metal chips, fluorspar is additionally introduced in an amount of 1.0–3.0 wt.%, And as a reducing agent, an aqueous solution (30%) of technical lignosulphonate precipitate in an amount of 0.5-10.5 wt.% , which has the following chemical composition, wt.%: carbon 57.3-65.8

the volatile gas part is hydrogen 4.3-5.2

nitrogen 0,3-0,6

oxygen 14.6-16.2

sulfur 1.6-2.3

ash else. Fluorspar is used with a fractional composition of 0.3-2.0 mm. 2 hp f-ly, 1 tab.

Description

The invention relates to metallurgy, specifically to the preparation of charge materials for smelting iron, and can be used in the preparation of liquid iron for the production of castings for various purposes.

The aim of the invention is to reduce the cost of the charge, increase the fluxing ability and strength of the briquette.

In preparation for briquetting, fluorspar in the amount of 1.0–3.0 wt.%, As well as an aqueous solution of technical lignosulfonate sludge as a reducing agent, 0.5– 10.5 wt.%, Are introduced into the chips.

Sludge of technical lignosulfonates is a reducing agent and at the same time binding and is a material formed during the storage of liquid lignosulfonates in foundries when used as binders for the manufacture of rods. It is easily removed from the tanks using an air-steam mixture. Sludge of technical lignosulfonates from storage tanks are not used anywhere for industrial purposes and are completely removed to the dump.

The solid residue of technical lignosulfonates (TOTJIC) has the following chemical composition,%: C 57.3-65.8;

Ј

vj j

SL SP

llrr 4.3-5.2; NrO, 3-0.6; or 14.6-16.2; otw, 1.6-2.3; Ls the rest. Ash TOTHS consists of oxides of calcium, magnesium, silicon and aluminum.

To improve the wettability of briquetted materials, it is advisable to use an aqueous solution of TOTLS (30%).

The consumption of the TOTLS is interconnected with the consumption and the fraction of the fluorspar.

When the content in fluorspar briquettes in an amount of less than 1% by mass, there is no flux effect. iron oxides with a content of more than 3 wt.% briquettes are showered with a greater weight loss. When the TOTLS content is less than 0.5 wt.%, The briquettes have insufficient strength, and when the content is more than 10.5 wt.%, They harden when cured with a sharp decrease in strength.

When the fluorspar fraction is less than 0.3 mm, the briquette is formed well, but when using such a fraction, in the absence of a significant increase in the strength of the briquette, the cost of grinding increases. When size

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in the form of smolny residues, it remains 2.8-2.9%. These losses are determined by weighing the prepared briquettes before and after testing them for mechanical strength. Double and triple handling of the proposed briquettes does not lead to their destruction and fragmentation.

The compositions of the tested briquettes and their properties, as well as briquettes from a known mixture are given in the table.

To study the degree of fluxing of harmful impurities from the melt, experimental melts are carried out in a crucible furnace, 5 of which the briquettes are lowered onto the surface of the molten metal at 1300 ° C and after their complete dissolution, metal samples are taken and analyzed for the content of iron oxides FeO.

From the results (Tests it follows that briquettes based on ferrous metal chips have good fluxing ability, lower heat treatment temperature and higher strength compared to the prototype. In addition, they have lower cost due to the use of technical lignosul sludge.

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slices over 2.00 mm dramatically reduces jq-fonates as a reductant with briquette strength. For the manufacture of briquettes, it is most advisable to use the waste grinding of fluorspar for other needs.

The briquette is prepared as follows. The solid residue of technical lignosulphonates is diluted in water. As fluorspar, its four-fraction powders are used (not more than 0.3; 0.3-1.0; 1.0-2.0 and 2.0-3.0 mm).

As shavings of ferrous metals using chips of gray cast iron SCH-18.

Powders of fluorspar and cast iron shavings are mixed together, then an aqueous solution of sludge from technical lignosulphonates in the amount of 0.3-11 wt.% Is fed to them and the whole mixture is mixed until a homogeneous composition. The molding of briquetted samples is carried out in the usual way on a briquetting press. They are heated in an oven to 225 ° C.

The test of briquettes for mechanical strength is carried out in accordance with GOST 2787-63. The total weight loss of briquettes after a threefold drop of 2.2-2.4%, while a loss in weight of briquettes with reducing agent in

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binds, which are available in sufficient quantities directly in the foundry shop, as well as due to the lower temperature of heat treatment. In briquettes with fluorspar with a fraction of more than 2 mm, scattering of briquettes is observed.

When the furnace reaches the melting temperature of the briquette, hydrocarbons intensively burn out of it, containing lignosulfonates in the sediment, to form pyrocarbon. In addition, the carbon contained in the solidified TOTLS plays the role of reducing bodies for iron oxides formed during storage, transportation and processing of metal chips Fluorspar contained in the brewing agent acts as a flux preventing the chips from oxidizing unreduced iron oxide, thereby improving the quality of the iron.

In machine-building enterprises, in large quantities I have all the components that constitute production waste. The production of high-quality charge material from these production wastes.

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Q Fonates as a reductant

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binder, which is available in sufficient quantity directly in the foundry, as well as due to lower heat treatment temperature. In briquettes with fluorspar with a fraction of more than 2 mm, crumbling of briquettes is observed.

When the melting temperature of a briquette is reached in the furnace, hydrocarbons containing 1-eu in the lignosulfonate precipitate burn out intensively, with the formation of pyrocarbon. In addition, the carbon contained in the solidified TOTLS plays the role of a reducing agent for iron oxides formed during the storage, transportation and processing of metal chips. The fluorspar contained in the briquette serves as a flux that protects the chips from oxidation and binds unreduced iron oxides, thereby increasing the quality of the iron.

In machine-building enterprises in significant quantities there are all the components that are components, which are production wastes. Production of high-quality charge material from these production wastes.

for smelting pig iron, it is economically beneficial for enterprises to establish and organize waste-free technology.

The proposed briquettes based on ferrous metal chips are recommended for use in smelting iron in cupolas, as well as in smelting synthetic or semi-synthetic cast iron in electric furnaces characterized by a low ability to graphitize and modify.

Claims (3)

1. Briquette for the smelting of pig iron containing chips of ferrous metals and a reducing agent that distinguishes charge, increase fluxing ability and strength, it additionally contains fluorspar, and as a reducing agent is an aqueous solution of sludge technical lignosulphur 5.5 0.9 5.5 , 0 5.5 2.0 777556 backgrounds in the following ratio, wt.%: Aqueous solution of sediment technical lignosulphonates 0, 5-10,5 Fluorspar 1,3-3,0 Black shavings metalsEverything else Sec. 2. A briquette according to claim 1, characterized in that the solid residue of technical lignosulphonates has the following chemical composition, in wt.%: Carbon Volatile gas part is hydrogen Nitrogen Oxygen Sulfur Ash 57.3-65.8 4.3-5.2 0.3-0.6 14.6-16.2 1.6-2.3 Else vom 0.3-2.0 mm .. vom 0.3-2.0 mm .. 3. Briquette according to claim 1, characterized in that fluorspar is used with fractional composition 250 Durability is good Sent - Formed by horopo g Showered Forms Choir ".- Is fallen asleep Formed choir i Choropo formed -Filled Fallen down When hardened, they swell There is no effect of flues when melting Remains The effect of flux is good Fallen down The effect of the crown ofks 5.5 5.5 3.0 3.1 91.5 91.4 1.0-2.0 7.0-3.0 0.3 P.3-1, O 1.0-2.0 7.0-3.0 -0.3 0.3-1.0 1.0-2.0 2.0-3.0 The continuation of the table 225 775 Fallen down CTtuiwcoBatms bovine effect Osiplets Lose 1 Carry Over 3Z