SU1668409A1 - Method of producing fluxes by electric melting - Google Patents

Abstract

This invention relates to ferrous metallurgy, in particular, to the production of fluoride-oxide fluxes for electroshock surfacing and welding. The goal is to reduce environmental pollution and improve technical and economic indicators for flux melting. The method includes loading into the furnace a mixture containing sand, manganese ore, lime, magnesite, fluorite and alumina. Alumina is introduced as a gas cleaning product for aluminum production containing solid solutions with the ratio AI ₂ O ₃ : CAF ₂ = 3.3 ... 7. First, 30 ... 40% of the total product volume is introduced into the furnace, and the remaining 60 ... 70% is mixed with the rest of the charge components. The method makes it possible to completely replace alumina, reducing power consumption by 10-20 kW ^. h / g, and fluorine concentrate, to reduce environmental pollution by reducing the release of volatile fluoride compounds. 1 tab.

Description

The invention relates to ferrous metallurgy, in particular, to the production of fluoride-oxide fluxes for electroslag surfacing and welding.

The purpose of the invention is to reduce environmental pollution and improve the technical and economic indicators of flux smelting.

The method consists in that aluminum oxide is introduced in the form of a gas cleaning product of aluminum production with a content of solid solutions - and CaPr with a ratio of Al2203: CaF2 of 3.3-7.0, while first 30-40% of the total amount of the mixture is introduced into the furnace, and the remaining 60-70% - in a mixture with the other components of the mixture.

The product of gas cleaning aluminum production contains, wt%: SI02 0.4-1.7; FeO 0.9-1.8; 69-78; CaF2 11-21; K20 + Na20 2.0-4.5; From 1.5-3.0.

The introduction into the furnace of gas cleaning products of aluminum production with a content of solid solutions of aluminum oxide and calcium fluoride with the ratio AlaOs:, 3 does not allow to reduce the activity of CaF2 in the flux melt, which leads to the intensity of the reactions:

ZSaP2 + 7 ± 3CaO + 2AIF3, (1)

2CaF2 + Sl02 2CaO + SiF4. (2)

The latter leads to the intensity of the flight of fluorine, which leads to an increased consumption of fluorite concentrate.

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Loading gas purification products with a ratio in solid solutions ABOZ: CaFa 7.0 leads to refractoriness of the charge, which leads to additional power consumption, reduced performance, and consequently, the deterioration of technical and economic indicators.

Loading this product into the flux-smelting electric furnace at the beginning of smelting less than 30% of the total volume leads to an increase in the sulfur content in the finished flux as a result of the transition from the metal phase to the flux melt (MnS / fMnS), as the diffusion processes of MnS increase, and more than 40 % - to the formation of manganese carbides (MnsC2, etc.).

The introduction into the furnace of a gas cleaning product of aluminum production in a mixture with the remaining components of the charge in an amount of less than 60% of the volume of the product does not allow to obtain fluxes with a reduced phosphorus content and does not reduce the activity of calcium fluoride, which does not allow to reduce fluorine losses. A product load of more than 70% increases the viscosity of the flux, which impairs deposition of the formed (Mn) and / Mn / on reactions:

MpO + + {CO}, (3)

(СазР04) + С Ј З (СаО) + (Р) + {С0} |, (4)

/ MpU + R / MpR /, (5)

which degrades the quality of flux. In addition, an increase in flux viscosity impairs the separation of slag crust from metal during surfacing and welding.

Under identical laboratory conditions, a comparative analysis of the chemical composition and consumption of charge materials such as AN-26C is carried out.

The furnace first load the gas cleaning product of aluminum production in the amount of 7; 8.4; 9.8; 11.2; 12.6 kg, which corresponds to 25; thirty; 35; 40; 45% of the total volume of the product to be specified, and then fluorite (29.2,) is loaded; magnesite (20.7 kg); sand (28.3 kg) manganese ore (3.8 kg) and gas cleaning product in the amount of 21; 19.6; 18.2; 16.8; 15.4 kg, which corresponds to 75; 70; 65; 60; 55%. The gas cleaning product of aluminum production is used with solid solutions of aluminum oxide and calcium fluoride with an AlaOa: CaFa ratio of 3.0; 3.3; 5.15; 7.0; 7.5. The finished flux is drained into molds and crushed. Samples of flux type AN-26P are subjected to chemical analysis.

In the smelting of flux in the known method in the flux furnace is loaded; fluorite concentrate (27 kg); alumina (19.8 kg); magnesite (20.7 kg); sand (28.7 kg); manganese ore (3.8 kg).

The results of chemical analysis of fluxes and technical and economic indicators, in particular the consumption of charge materials, are given in the table.

As shown by experienced melting, fluxes

Smelted in variants 1 and 5 do not satisfy the requirements of TI on the content of calcium fluoride, sulfur and phosphorus. Melted fluxes according to options 2-4 meet the requirements of

flux content of all components. They have lower concentrations of phosphorus (0.03-0.06%) and sulfur (0.04-0.06%), which is 0.05-0.08 abs.% And 0.04-0.06 abs. .%, respectively, compared with the known method. In addition, the consumption is reduced

fluorite concentrate at 8.8 kg per 1 ton of finished flux. The latter improves not only the technical and economic indicators, but also the sanitary and hygienic working conditions of the staff and the environment. The consumption of sand decreases by 4 kg per 1 ton, which is associated with a decrease in CaF2 activity, and this inhibits the regression process (2). Using the product allows you to completely replace alumina and

reduce electricity consumption by 10-20 kWh / t.

Thus, the results of flux analysis show that the use of the proposed method allows

production to reduce the loss of fluorine and improve technical and economic indicators.

Claims (1)

The invention The method of obtaining flux by electrofusion mainly for electroslag surfacing and welding, including batch charge loading, containing fluorite concentrate, magnesite, sand, manganese ore and aluminum oxide, about t that in order to reduce environmental pollution and improve technical and economic performance, aluminum oxide is introduced as a gas cleaning product of aluminum production with by keeping solid solutions of aluminum oxide and calcium fluoride with the ratio A (2O3: CaF2 3.3-7.0, while first 30-40% of the total amount of the product is introduced into the furnace, and the remaining 60-70% are mixed with the remaining components of the mixture. 22.2-20.728.33.8283.0 22.2-20.728,33,8283.3 22.2-20,728,33,8285,13 22.2-20.728,33.8287.0 22.2-20.728.33.8287.5 311,820,729,7З.в 25 7 75 ST 8,419,6 3565 OTT 4060 77717 73 307,33,218,4 22,417,41,00,12О, .О 31,072.923.3 20,517,30,80,06О.040.03 32,44,4.3,122,48 21,615,30,70,03 °. 31,94,373,021,6 22,316,10,60, .060.03 45 5530.9 6 3.5 19.21 22.0 17.2 0.9 0.11 0.1 757 T374 0.08 0.05 30.2 7.4 Z, 9 19.6 20.34 17.8 1.0 0.11 29-33 4-8 2.5 20-24 19.23 15-18 1.5 0.10.10.05 1430 1400 1390 1J80 1500 1600 -0 about 00 L about with