SU629235A1 - Reducing mixture - Google Patents

Description

The invention relates to the field of ferrous metallurgy, namely, to the production of ferroalloys, in particular to reducing mixtures for melting silicon-containing ferroalloys. There are known mixtures for the production of ferrosilicon, which include a reducing agent, a mixture of coke and semi-coke, while the coke content ranges from 4O to 45 wt. % of the mixture, the rest is a semi-coke TlJ. The reducing mixture has a number of disadvantages: the formation of silicon carbide (Sic), especially in areas with a low temperature. This leads to the formation of refractory weakly reactive compounds, which are slowed down by the charge of the crucible-thermal furnace during the use of a mixture of coke and semi-coke due to the weak adsorption capacity, a substitute of lower silicon oxide — silicon monoxide (SiOa) occurs — the mixture has a low absorbing capacity of SiOa. 0. Due to the high flyaway of silicon monoxide, the use of silicon is reduced, and the performance of the production of silicon-containing ferroalloys deteriorates. The aim of the invention is to reduce the carbide formation and fly away of VIA monoxide cream. This is achieved by the fact that the mixture additionally contains ½ grain cellulose and cellulose in the following ratio {weight ratio, weight. %: Semi-cokes; 30-7O Lignin5-23 Cellulose 0.2-5 Cox. The remaining Reducing mixture of smelting silicon-containing ferroalloys is obtained by grinding the mixture components to a fraction less than 20 mm. Then the components are mixed. The composition of the mixture includes lignin with a content of 50-7O%, 3-9% n,. 20-30% o, cellulose with a ratio of elements corresponding to the formula CgHjoOj. The reduction mixture is used for smelting of silica-containing formaficides: ferrosilicon, ferrosilic chromium and other ferroalloys by melting together with quartzite (more than 90% Si O5) metal additives (steel shavings, carbon ferrochrome). The melting is carried out in a ore-smelting furnace with a gradual nakedness of aagruzheyl materials up to. In the heating of the heat, the pyrolysis of the mineral is applied to the cellulose. with the release of gas-forming products of destruction, which hinders the development of the reaction of the formation of silicon carbide on carbon materials of reducing mixtures at temperatures of 12OO-1500 ° C. When gaseous products come to a carbon-like material of reducing mixture, radicals are formed in the pores, and a mixture of solvent can form in the pores. to myochem. The impact of drywall "abravkyk. products (hydrocarbons) on carbonaceous material (coke and semi-coke increases their actuality with respect to gaseous monoxide in belts (SiO). of the process of recovery of silica and the formation of silicon-containing ferroalloys increases by 5-10% and the loss of silicon compounds (S ()) with waste gases is reduced by 1.2-1.6 times. The lignin content in the reducing mixture is less than 5% by weight and the amount of cellulose is less than 0.2% by weight, the carbidization process on the carbonaceous material is accelerated and as a result the rate of reduction of silica decreases. In addition, the amount of lignin in the reducing mixture is more than 23% by weight and cellulose is more than 5 wt.% intensive mixture gasification and deterioration of the conditions of service of smelting furnaces occurs Test of a reduction mixture of oxygen in laboratory conditions in a furnace with Tpy64aTb "s graphite heater when heated to 1800 C. In reduction mixture of roToBsrr from semi-coke and coke with the addition of lignin and glucose. The reduction mixture is introduced into the composition of the charge for smelting 75% ferrite core. Iron powder is used as the iron component. The components of the mixture are mixed, placed in an electric furnace, heated to 18OO C and incubated for 20 mn. In the melting products, the content of silicon carbide is determined, as well as the fly of silicon monoxide. The test results of the reduction mixture are given in the table.

Thus, the use of a reducing mixture of the proposed composition reduces the content of silicon carbide in 3-6 (7 para and the fly of silicon monoxide on

ForiLula invention

Reducing mixture for flushing silicon-containing ferroalloys, containing coke and semi-coke, O tl and 5 6292356

with the aim that Cellulose 0.2-5

reducing carbide formation and fly away

silicon oxide, it is replenishing. Sources of information taken in

contains lignin and cellulose when barely attention during examination:

Avushem component ratio, weight,%: 1. Shetsroviik Ya. S. Prosvvotstvo

Semi-coke 30-7OS ferroalloys in closed furnaces, M „

Lignin 5-23 Metallurgists, 1975, p. 278-279.