SU881143A1 - Method of producing vanadium alloys - Google Patents

Description

one

The invention relates to ferrous metallurgy and can be used. but in ferrovanadium production.

A known method for the production of ferrovanadium directly from slag obtained during the processing of vanadium-containing iron. According to this method, slag containing 6–20% V as an oxide and 20–45% FeO, and lime is smelted in an electric furnace with heating of the melt to 1550–1750 ° C. Ferrosilicon is introduced into the charge in such a quantity as to completely reduce iron oxides. Let the metal be released from the furnace, and the shpak is left in the furnace (the metal is separated from the slag). The remaining vanadium-enriched slag is poured into a ladle, where the crushed (fraction b, 2-5 mm) ferrosilicon is continuously and evenly loaded to recover the oxidic acids. A reducing agent (ferrosilicon) is taken in excess in order not only to reduce vanadium oxides, but also to obtain 3-10% silicon in the alloy. Lime is taken in such an amount that the CaO / 510L ratio after the final reduction is in the range of 1.0-2.0 1.

The disadvantages of this method are that the process is conducted in an electric furnace. The charge is loaded onto the hearth and therefore melting it from the arc takes a long time (iOOO kg of slag, 700 kg of lime and 90 kg of ferrosilicon melt for 1.5 hours). The interaction of slag and reductant was carried out only by

10 mixing caused by natural convection, which limits the possibility of intensifying the process. In addition, with the complete reduction of iron, a large amount of vanadium passes into it in the first stage 5, which leads to its practical loss. The increased loss of vanadium is also due to the high consumption of lime in the second

Stage 20 in connection with increased slag yield. At a lime consumption calculated on receipt after the final slag reduction with a CaO / SiOj ratio of 1.025 2.0, 1.4 g of reduced slag are obtained per ton of raw slag. The increased amount of final slag causes increased vanadium losses in metal beads,

30 entangled in the slag. According to the specified

reasons vanadium extraction from the mixture does not exceed 80%. In addition, the final reduction is carried out in the ladle and the interaction of the reducing agent and slag takes place only due to the energy of mixing of the jet of slag that is drained into the ladle.

The purpose of the invention is to reduce the vanadium perhode into the reduced iron and the loss of vanadium with final (varnishes.

The goal is achieved in that the reducing agents for the selective reduction of iron are introduced at the rate of reducing the content of iron oxides in the melt to 4.5-7.5%, and the lime in the vanadium-rich vanadium is introduced in an amount that provides the ratio of calcium oxide to silica in the final slag 0.1-0.9.

The melting of materials and the implementation of the process are most expediently carried out in the converter, because, due to the intensive mixing of the phases due to the kinetic energy of the torch, melting takes place at high speed (2-3), approximately by an order of magnitude greater than in an electric furnace. When the temperature of the melt is above 1350s, metallothermic is introduced into the converter. E. Reducing agents, for example, ferrosilicon. The consumption of reducing agents must ensure that the content of iron oxides in the melt is reduced to 4.5–7.5%. The indicated contents of iron oxides provide an insignificant (3.0%) vanadium transition to the reduced metal in the first stage with a residual content of iron oxides of more than 4.5%. The presence of iron oxides of more than 7.5% leads to a decrease in the vanadium content in the finished alloy. An important aspect of the technology, which provides high technical and economic indicators, is the slag mode, determined by the consumption of lime. It determines the durability of the lining, as well as the loss of vanadium with the final slag (in the form of wimples entangled in the slag). These losses increase in proportion to the amount of slag produced. At the same time, it is impossible to completely exclude lime, since in this case slags are viscous and vanadium losses in the beads increase in intensity. Considering the available research results, lime consumption should ensure that the final slag with the CaO / SiOj index is within O, 1-0, 9. It is optimal to have a CaO / SiOQ ratio in the range of 0.4-0.6, at which both the best durability of the refractory lining is provided, as well as the low viscosity of the slag. The yield of final Eilak at this time is 1.1-1.2 tons per ton of initial vanadium slag. Compared with the known yield of the final slag.

accordingly, vanadium crowns losses are reduced by about 1.2 times.

In the process of selective reduction of iron, as a result of the short duration of reduction, a large amount of heat is released, therefore it is advisable to use coolers. As a cooler you can use pig iron. The use of cast iron, along with a cooling effect, allows an increase in the carbon content of the reduced alloy, which is favorable due to a decrease in its melting point.

EXAMPLE 1.V converter (with a capacity of 8.4 m) with bottom tuyeres of the pipe type in the pipe is loaded with bt vanadium slag containing 17.17% and 27.4% iron oxides and 1.5 tons of lime. Through an oxygen-fuel purge of 25 minutes (oxygen 25, natural gas 10 mummies), the mixture is melted and heated to 1350 s. After that, 300 kg of cold iron is loaded into the converter and the selective reduction of iron is started, for which, by blowing the melt with air-gas blast (air 12.0, natural gas 3.0), 750 kg of 75% ferrosilicon are introduced into the converter. After the b min has been mixed by air-gas blasting, the converter shaft t and merge 1.8 tons of alloy from it (0.27% C, 1.34% U, 0.03% Si, 0.037% S and 0.045% P). The slag melt remaining in the converter by this moment contains,%: iron oxides 4.72; , 40, SiO 35.2, CaO 22.4 and other oxides. To completely reduce the vanadium oxides and iron of this melt, lime, 500 kg of 75% ferrosilicon and 400 kg of aluminum are introduced into the converter with air-gas blasting (air 13.5 MVMHH, natural gas 3.2) with stirring for 8 minutes. At the end of the process receive. 2.29 tons of alloy containing,%: Y 22.18, SiO 11.9, C 19, MrvlO ,; S 0.010, P 0.040, the rest is iron. The final slag contains,% U,., O5 0.51, SiO 39.0, CaO 23.04, A1POE) 15.8, MDO 8.36 and other oxides. The ratio CaO / SiO is equal to 0.6.

Claims (1)

Example2. 5 tons of vanadium slag containing 17.92% U1O5 and 28.43% iron oxides and 2 tons of Lime are loaded into the converter. After 20 minutes of the oxygen-fuel purge (oxygen 22.5, natural gas 9), the mixture is melted and heated to. After that, 200 kg of cold iron are loaded into the converter, and 600 kg of 75% ferrosilicon are produced with air-gas blasting (air 10.0, natural gas 2.5) with mixing. After 5 minutes, the converter shaft and t merge from it 1.23 tons of alloy (0.32% C and 0.16% V). Slag melt contains 6.10% of iron oxides and 10.40%. To completely reduce the oxides of vanadium and iron, lime, 500 kg of ferro-sicil and 310 to aluminum are introduced into the converter with air-gas blasting (air 12 m / min, natural gas 2.5) while mixing 8 min. At the end of the process, 2.10 alloys are obtained containing,%: Y 22.38, Si 8.41, C 0.24, Mh 7.54, S 0.010, P 0.070, the rest is iron. The final slag contains,%: 0.56, SiO / j, 33, CaO 29.9, 3.6; MDO 11.2 and other oxides. The ratio CaO / SiO2 is 0.9. Example 7 tons of vanadium slag containing 17.60% and 29.2% of iron oxides and 1 ton of lead are loaded into the converter. After 30 minutes of an oxygen-fuel purge (oxygen 20 mUmin, natural gas 8.5 m / m, the mixture is melted and heated to 1400 s. Then, 350 kg of cold iron and 700 kg of 75% ferrosilicon are loaded into the converter blown (air 15.0, natural gas 3 m3 / min) After 6.5 minutes, the converter is shaft t and 1.67 tons of alloy is drained from it (0.12% U and 0.38% C). Slag melt contains -7 , 47% iron oxides and 12.80% Al for the complete reduction of vanadium oxides and iron, lime is introduced into the convorter, 600 kg of ferrosilicon and 500 to aluminum with air and gas mixing blown air (air 12, natural gas 3.2 m UMIN) 3.5 minutes. At the end of the process, 2, OU t of alloy containing,%: U 21.25, Si 15.2; Mts 10.78; C 0.19, S 0.011, P 0.033, the rest is iron. The final slag contains 0.16, SiO j 37.8 CaO 19.2, Al-jiOi, 16.7, MgO 7.8 and other oxides. CaO ratio: Si02 0.5. The proposed method significantly simplifies the technological scheme for the production of vanadium alloys significantly increases the productivity of the aggregates, improves the extraction of vanadium up to 88%. The invention method of producing vanadium alloys, including the melting of vanadium-containing slag and lime, the selective reduction of iron and the separation of the melt, the additional recovery of the melt rich in oxides of vanadium vanadium, characterized in that selective reduction of iron is introduced, reducing the content of oxides in the melt to 4.5-7.5%, and the lime in an oxide-rich vanadium melt is introduced in an amount bespechivaet ratio of calcium oxide to silica in the final slag 0.1-0.9. Sources of information taken into account in the examination 1. US patent W 3579328, cl. 75-1335, 1971.