SU1477761A2 - Method of producing ferrochrome - Google Patents

Abstract

This invention relates to the field of metallurgy, specifically to the production of chromic ferroalloys. The purpose of the invention is to obtain ferrochrome with a carbon content of less than 0.020%. Chrome-limestone melt is reduced outside the furnace by liquid ferrosilicochrome when loading up to 3-16% of solid additive from the mass of the melt. The ratio of lime to chrome ore in a solid additive is (0.2-0.5): 1. The loading of the solid additive begins after pouring 25% of ferrochrome and ends when pouring 90% of ferrochrome. The method allows to obtain ferrochrome FH001 with a carbon content of 0.015-0.019%, does not impair the technical and economic indicators. 1 tab.

Description

The invention relates to metallurgy, in particular to the production of chromic ferroalloys, and is an improvement of the method according to Aut. St. No. 1331900.

The aim of the invention is to obtain ferrochrome with a carbon content of less than 0.020%.

The ratio of lime to chromium ore in the solid additive loaded into the reactor during the recovery of the ore-lime melt (RIR) with ferrosilicochromium is maintained within (0.2-0.5): 1, the consumption of the additive is 3-16% by weight of RIRA, and after addition, the entire additive is uniformly loaded from 25% and up to 90% of the ferro-silicochrome poured in for melting.

When lime is consumed in a solid additive of 0.2, it significantly decreases because of chromium, while at a rate of more than 0.5, the thermal terminus of the process and the probability of producing ferrochrome with a content below 0.020% carbon decrease.

When the consumption of solid additives is less than 3%, the productivity decreases due to the decrease in the amount of the material being melted; the consumption of more than 16% leads to an increase in the carbon content in the alloy above 0.020%.

In order to more intensively burn carbon from charge metals of solid additives and oxidize it from the resulting ferrochrome during the reduction of RIR in the first period, it is advisable to raise the temperature of the melt due to the exothermic reactions of silicon thermal reduction of iron and chromium. In this case, the crust on its

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surface in the reactor. / 1l of this pour at least 25% of the ferrosilicochromium intended for smelting. In order to completely dissolve the solid additive, it is advisable to finish its loading by pouring 90% of the ferrosilico-chromium at the latest.

Chrome-limestone melt (RIR) is produced in a refining electric furnace with a transformer capacity of 5 MBA. From the furnace, 7 tons of melt are drunk into the lined ladle-reactor and placed on the mixing unit. | Example 1. A solid additive with a lime-to-ore ratio of 0.5 in the amount of 15% by weight of the melt (700 kg of chrome ore and 350 kg of lime with a carbon dioxide content of 2.2%) is fed to a special mixing unit hopper, first lime then ore. After pouring 370 kg of ferro-silicon chromium containing silicon

Method for the production of ferrochrome

51% begin loading solid additives (lime first, and then chromic 25po auth. St. No. 1331900, about l and h ore). The loading of a solid additive was compounded with the fact that, for the purpose of semi-breeding, pouring 700 kg of ferrochrome with carbon-silicon-chromate ferrochrome, and after it ended the genus less than 0.020%, another 390 kg of reducing agent was added to the solid additive. 3-16% by weight of the melt. Two overflows of the products are carried out. Melting starts evenly after

Key from bucket to bucket. The carbon content in ferrochrome 0,018%.

Example 2. Solid additive with the ratio of lime to ore, equal to

pouring 25% and ending when pouring 90% of the amount of ferrosilicochromium intended for smelting, while the ratio of lime to chromium ore in

Lime with a carbon dioxide content of 1.8%) is fed into a special bunker (first lime, then ore). After pouring 400 kg of ferrosilica chromium (29% of the calculated mass) with a silicon content of 51.5%, a loading of the solid additive is started, accompanied by pouring 650 kg of ferrosilicochrome. After loading the solid additive, another 330 kg of reductant are poured. Two overflow products from the ladle to the ladle are made. The carbon content in ferrochrome 0,013%.

Claims (1)

The effect of the lime / chromium ore ratio in the solid additive on the carbon content in ferrochrome, the extraction of chromium and the productivity of the process are given in the table (the consumption of the solid additive is 12% of the mass of the PID). Invention Formula Method for the production of ferrochrome on auth. St. No. 1331900, about a t of l and h aa yu and, so that, in order to obtain ferrochrome with a carbon content of less than 0.020%, a solid additive in the amount of 3-16% by weight of the melt begins to load uniformly after pouring 25% and ending when pouring 90% of the amount of ferrosilicochromium intended for smelting, while the ratio of lime to chromium ore in 0.26, in the amount of 9% by weight of the solvent additive (0.2-0.5): water (500 kg of chrome ore and 130 kg Indicators Lime to ore ratio 0.1 G 0.2 G 0.35 0.50 T 0.6 JO, 35 0,015 0,016 0,018 0,010 0,010 0,012 0,013 0,014 0,016 79, 1 80,4 81,4 100,1 100,0 99,8  The known method. Editor N. Gunko Compiled by Oh Veretennikov Tehred L.Oliynyk 0.022 0.024 0.018 0.020 0.020 0.021 82.0 82.1 82.2 99.5 98.8 96.2 Proofreader A. Obruchar