RU2201467C2 - Method of production of vanadium-containing ferroalloy - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: proposed method includes introduction of carbon-containing component into charge in the amount sufficient for content of carbon of 15-30% of mass and ferrosilicon in the amount of 5-10% of mass of charge. Prior to reducing treatment of vanadium-containing slag, metal is tapped. After reducing treatment, repeated heating of modified molten slag is performed. Used as silicon-containing material is mixture of ferrosilicon with calcium silicon in the amount of 10-20% of mass of vanadium-containing component of charge at ratio of ferrosilicon and calcium silicon in mixture of 3: 1 to 10:1, respectively. Proposed method makes it possible to obtain ferrovanadium at high concentration of vanadium and ferroalloy at minimum concentration of vanadium. EFFECT: enhanced efficiency. 2 tbl

Description

 The invention relates to pyrometallurgy and can be used in the production of ferroalloys.

 Known methods for producing vanadium from mineral materials of technogenic origin - slag, sludge, ash, pitch, etc. A number of methods are based on leaching the chemical compounds of vanadium from the feedstock and subsequent thermochemical reduction of these salts, leading to the formation of vanadium-containing ferroalloys.

 Leaching of vanadium salts is carried out by various hydrometallurgical methods. According to the method described by Patting S., Makheri T.K., Gupta C.U. "Met. Trans", 1984, 814, 1-4, pp. 133-135, as a result of leaching of vanadium salts, liquor is formed, from which iron vanadate is isolated. Ferrovanadium is obtained from the latter by aluminothermic treatment.

 Also known is a method of alloying steel with vanadium contained in vanadium-containing converter slag (A. A. Smirnov et al. Vanadium-containing alloying materials and the effectiveness of their application. M., Express information CRI and TEICHM, 1986).

 Closest to the technical nature of the claimed is a method for producing a vanadium-containing alloy, comprising loading and melting in a furnace a mixture consisting of vanadium-containing and carbon-containing components, ferrosilicon, obtaining a molten metal and vanadium-containing slag, and the reduction treatment of vanadium-containing slag with silicon-containing material (products of a M-grade fused material, .A. Production of Ferroalloys. M., Metallurgy, 1985, p. 303).

 A significant common drawback of the known methods (and this is the reason that impedes the achievement of the expected technical result) is the possibility of obtaining only multicomponent ferroalloys, which, in addition to vanadium, contain increased amounts of manganese, iron, chromium and other metals.

 The basis of the invention is the task in a method for producing vanadium-containing ferroalloy by changing the process parameters and their sequence, as well as introducing new operations to achieve separate production of ferrovanadium with a high concentration of vanadium and ferroalloys with a minimum concentration of vanadium.

 The problem is solved in that the carbon-containing component is introduced into the charge in an amount providing a carbon content in the charge of 15-30% of its mass, and ferrosilicon in an amount of 5-10% of its mass, before the reduction treatment of the slag melt, the metal melt is released, after the recovery treatment, re-heating of the modified slag melt is carried out; in this case, a mixture of ferrosilicon with silicocalcium in the amount of 10-20% by weight of vanadium-containing co is used as a silicon-containing material batch component with a ratio of ferrosilicon to silicocalcium in a mixture of 3: 1-10: 1, respectively.

 Usually, vanadium is a part of converter slags formed during the redistribution of vanadium-containing pig iron, fuel oil ash, pitch, slag of chemical industries, etc. To obtain ferroalloys with a high content of vanadium in the furnace, it is necessary to recover and separate the maximum amount of iron and other charge metals from vanadium. When the heated charge is melted in an electric furnace in the presence of carbon and silicon, the metal is separated from the slag, which contains almost all the vanadium of the charge. The resulting metal is poured into a ladle and then poured into castings (ingots). Liquid slag is subjected to metallothermal treatment with a mixture of ferrosilicon with silicocalcium. The quality of such a mixture depends on the composition of the slag and is 10-20% of the vanadium-containing component of the charge. After mixing the slag with the mixture and co-melting, the vanadium-containing material and the slag are separately drained. The vanadium-containing material is ferrosilicon vanadium with a vanadium content of 50% and higher. It is poured into molds. If it is necessary to obtain ferrovanadium, additional processing of ferrosilicon vanadium by technical vanadium pentoxide is performed. Processing can be done in the oven or in the bucket. The slag formed after the production of ferrovanadium from ferrosilicon vanadium is introduced using technical vanadium pentoxide into the charge, which is melted to separate heavy metals from vanadium-containing slag. The waste slag formed after the preparation of ferrosilicon vanadium can be processed into building materials.

Concrete example
The above parameters of the proposed method were originally obtained by appropriate modeling of the main thermochemical reactions. Further, this method and the parameters at which it is implemented were confirmed in laboratory conditions in an electric furnace with a capacity of 200 kV • A. In the furnace, the ash formed at a thermal power plant during the burning of fuel oil was melted. Ash composition: 20% V ₂ O ₅ ; 4.5% NiO; 0.5% MnO; 20% Fe ₂ O ₃ ; 1% Cr ₂ O ₃ ; 7% (CaO + MgO); 4% S; 10% C; 20% SiO ₂ ; 6% (K, Na) ₂ O; 7% A1 ₂ O ₃ .

 The metal was separated from the slag by separate discharge. Five laboratory swimming trunks were carried out in the presence of silicon with various addition of carbon, presented in table 1.

 From the table. 1 it follows that the optimal carbon content in the mixture should be 5-15%.

The remaining slag (23% V ₂ O ₅ , 16% FeO, 4% Cr ₂ O ₃ , 19% SiO ₂ , 36% CaO, 2% S) was reduced by ferrosilicon (FS-65) in a mixture with silicocalcium (CaCl 15).

 The data presented in table 2 indicate the feasibility of introducing ferrosilicon (FS-65) into the slag melt in a mixture with silicocalcium (CaCi 15).

After laboratory testing, the method was implemented in an electric furnace DSP-3. As vanadium-containing raw materials used ash of the above composition. The furnace was littered with flux (limestone) (≈1.5 t) and ash (≈1.7 t). 200 kg of coke and 100 kg of FS-45 were filled up. The electrodes of the furnace were lowered onto the mixture, an electric arc was ignited, and the mixture was melted. After the formation of the charge melt and the termination of open arc discharges, the voltage at the electrodes was reduced, the current strength was increased, and the melt in the furnace was heated to a temperature above 1500 ^o С. Upon completion of the melting and heating of the melt, the melt was released through a trench into the stopper ladle. At the time of release, a metal melt (0.15 t of an iron alloy with 28% Ni) and slag (23% V ₂ O ₃ , 16% FeO, 30% CaO, 19% SiO ₂ , 5% MgO, 2% S were formed in the furnace). , 5% A1 ₂ O ₃ ).

 Metal was poured into a mold through a pouring glass. When slag appeared, the stopper closed the stopper and the ladle was returned by a crane to the furnace, from which the melts were released.

At the same time, a mixture of 150 kg of FS-65 and 50 kg of KaSi-15 was poured into the bottom of this furnace. After these operations, slag was poured from the ladle into the furnace when the arch was removed. The arch was lowered into the furnace, the electrodes were lowered into the slag, voltage was applied, and the slag was heated for 10 minutes. When reaching a slag temperature of more than 1500 ^o With the formed melts poured from the furnace into the bucket. From the ladle, the melts were poured into the mold, where the separation of metal and slag occurred. After cooling the melts, the slag was separated from the metal. The resulting metal had the following composition: 48% V, 15% Si, 2% Mn, 0.5% Ni, 2% Cr, 0.09% C, 0.08% S. The amount of metal is 250 kg.

Slag composition: 50% CaO, 40% SiO ₂ , 8% MgO, 2% S.

 Thus, as follows from the above evidence, the invention allows to achieve separate production of ferrovanadium with a substantially high concentration of vanadium and ferroalloy with a minimum concentration of vanadium.

Claims (1)

 A method of producing a vanadium-containing ferroalloy, including loading and melting in a furnace at a given temperature of a mixture consisting of vanadium-containing and carbon-containing components, ferrosilicon, obtaining a molten metal and vanadium-containing slag, reduction treatment of the vanadium-containing slag with a silicon-containing material, the production of carbonaceous products is different, the product is introduced, the carbon component being in the charge in an amount providing a carbon content in the charge of 15-30% of its mass, and ferrosilicon in an amount of 5-10% t of the mass of the charge, before the re-treatment of the vanadium-containing slag, the metal melt is released, after the re-treatment, the modified slag melt is reheated, and a mixture of ferrosilicon and silicocalcium in the amount of 10-20% of the mass of the vanadium-containing component of the charge is used as the silicon-containing material, with the ratio of ferrosilicon to silicocalcium in a mixture of 3: 1-10: 1, respectively.

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