SU1082853A1 - Alloying mixture - Google Patents

Abstract

: MOLDING MIXTURE, predominantly for iron-carbon alloys, including vanadium-containing slag. limestone and reducing agent, characterized in that, in order to reduce the cost of the alloying mixture, energy consumption and melting time, it contains bottom slag from fuel oil burning as vanadium-containing slag, and ferrosilicon and carbon as the reducing agent in the following ratio of components, wt. .%: Carbon 10-15 Ferrosilicium 3-5 Ivvestn to 8-10 Substeep slag from about $ burning of fuel oil Else (L

Description

1 The invention relates to metallurgy and can be used in a foundry and steel-smelting industry. The known alloying mixture for steel and cast iron containing vanadium slag, lime, fluorspar, fluorite, carborundum L. The disadvantage of this mixture is the high cost and the need for a high-temperature reduction mode (1560-1600 C) when the metal is doped, which increases energy costs. Closest to the proposed is an alloying mixture L, containing components in the following amounts, wt.%: Vanadium-containing slag 70-75 Carborund 12-16 Known to. The disadvantage of the known alloying mixture is its high cost (the presence of expensive metallurgical vanadium slag from the processing of va nadium iron and carborundum, the cost of which is 500 rubles per ton) and the low percentage of vanadium pentoxide B slag (not more than 20%). Therefore, when it is necessary to produce metal with a high content of vanadium (more than 0.3%), the weight of the alloying mixture is increased. The more a dopant mixture is loaded into the furnace, the more a speck is formed. This increases the recovery period of vanadium from slag, reduces the productivity of the smelting units, increases energy consumption in the production of metal. The purpose of the invention is to reduce the cost of the doping mixture, energy consumption and melting time. This goal is achieved by the fact that the alloying mixture is mainly for iron-carbon alloys, including vanadium-containing slag, limestone and a reducing agent, as a vanadium-containing slag contains new slag from the reduction of fuel oil, and as a reducing agent for ferrosilicon and carbon, the following ratio of components, by weight. %: Carbon 10-15 Ferrosilicon 3-5 Known to 8-10 53 Sub hearth from the combustion of fuel oil. The remaining effect of the alloying mixture is based on the active course of the process of vanadium oxide reduction by carbon and f rrosilitsiem. Carbon and ferrosilicon are selected as reducing agents in order to create reducing conditions over a wide range of temperatures. According to thermodynamic calculations, silicon entering into ferrosilicon is a more active reducing agent at low temperatures (1300 ° C), and carbon more actively restores vanadium from slag at temperatures higher than 1300 ° C. Combined use of carbon and ferro. as reducing agents, it allows active recovery of vanadium from slag over the entire temperature range of the smelting process. The selected total amount of carbon and ferrosilicon is sufficient to completely reduce the vanadium oxides contained in the slag. Reducing the percentage of carbon and ferrosilicon reduces the degree of reduction of vanadium from slag. Increasing the carbon and ferrosilicon content in a mixture of the above limit is impractical because carbon and silicon, which did not react with vanadium pentoxide, are converted into a metal, changing its chemical composition. At the same time, the consumption of the reducing agent increases. The selected weight ratio of ferrosilicon to carbon (1:: 2-1: 5) allows effective vanadium recovery at temperatures not exceeding 1450 C. Changing the ratio of ferrosilicon to the hazard above or below the specified limits reduces the degree of recovery of anadium, requires increasing temperatures vanadium reduction, increases the consumption of ferrosilicon and carbon. At the same time, the power consumption increases and the productivity of the process decreases... Known to allows obtaining the optimum viscosity of the slag, accelerates Zeon vanadium reduction processes. Increasing or decreasing the amount of CaO with respect to the indicated limit is higher. The viscosity of the slag slows down the diffusion process of vanadium reduction.

The bottom slag from the combustion of fuel oil contains 25–40% vanadium pentoxide, i.e. 1.5–2 times more than its content in metallurgical slag. The use of hearth from the combustion of fuel oil reduces the amount of doping mixture and its cost, increases the productivity of the process, and reduces power consumption. The amount of bottom slag from fuel oil combustion was selected on the basis of complete recovery of vanadium.

Experimental melting is carried out in a laboratory furnace with a graphite heater. The mass of pig iron containing, wt.%: C - 3.36; Si-2.21} Mn-0.56, Cr - traces; S - 0.057, - P - 0.093 will be 1 kg. The alloying mixture is introduced in an amount of 5% by weight of the liquid metal at 1400s. The exposure time is 40 minutes. In the experimental swimming trunks, hearth slag from the combustion of fuel oil containing,

wt.%: VjOj - 40.5; SiO, - 19.0, RelO - 10.8, the rest is NiO-oxides, etc., carbon in the form of electrode chips, crushed FS75 ferrosilicon, burnt lime.

After grinding, the components are mixed in the proportions indicated in the table, where the results of the experimental heats are presented. Melting was also carried out using a known

pegiruns mixture.

The use of the proposed alloying mixture reduces the cost of the alloying mixture by a factor of 7 to 7, reducing the amount of the mixture consumed by 40-45%; reduction of power consumption by 40-50%, reduction of melting time by 40-50%.

Claims (1)

DOPING MIXTURE, mainly for iron-carbon alloys, including vanadium-containing slag, limestone and reducing agent, characterized in that, in order to reduce the cost of the alloying mixture, energy consumption and smelting time, it contains a bottom slag from burning fuel oil as vanadium-containing slag, and as reducing agent - ferrosilicon and carbon in the following ratio of components, wt.%: Carbon 10-15 Ferrosilicon 3-5 Ivvestnyak 8-10 Hearth slag from burning fuel oil 00 N3 00 sl 00 to the proposed, owing to the following 70-75 12-16 Rest