SU922170A1 - Method for aluminothermal production of ferrotitanium - Google Patents

Description

(5) METHOD OF ALUMINOTHERMIC PRODUCING OF FERROTITANE

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The invention relates to metallurgy and can be used to obtain ferrotitanium by an aluminothermic method.

A known method for the extraction of metals from the slags of aluminothermic production, is that after the aluminothermic smelting of the charge, the liquid slag is drained into a separate container and an exothermic mixture is set on its surface with an excess of reducing agent. As a result of the interaction of the exothermic; mesium with the slag, a high-alumina product and complex alloys are obtained with an increased content of aluminum and silicon versus standard alloys and a reduced content of leading elements 1.

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The disadvantages of this method are significant heat losses during the transfer of slag into another tank, leading to a sharp decrease in slag temperature, which makes the process difficult and reduces metal extraction from the slag. To ensure the necessary conditions, additional heat is required by increasing the amount of the exothermic mixture or, due to electrical heating, which is associated with additional costs.

In addition, the complex alloys resulting from the treatment of the slag of an exothermic mixture due to the high contents of aluminum and silicon and the low content of the leading element in quality are inferior to standard alloys and therefore are not widely used.

The closest to. the technical solution ft proposed the method of aluminothermic smelting of ferrotitanium, including loading, melting of a mixture containing titanium concentrate, and aluminum, loading of thermite precipitator on the surface of the melt iron39, draining a part into a cast iron non-refractory metal base to form on the walls of the slag skirt, and a set of matte plates. and iron-thermal precipitator, discharge of the smelting products into the metal receiver 2. The disadvantages of the known method are low extraction of titanium. impossibility of simultaneous floor Cheney ferrotitanium and vysokoglinozemi of product suitable for preparing a synthetic rafinirupschih shlakbv and high alumina cement clinker. The aim of the invention is to simultaneously produce ferrotitium and high alumina product, to increase the recovery of titanium. The goal is achieved by the fact that according to the method including the charge and melting of the charge, the release of products, the mixture is first smelted, containing 20-50% of titanium concentrate of its total mass for smelting, with the ratio of the amount of aluminum to the stoichiometrically necessary to restore the extracted elements from their oxides are 0.9-1.3. then the mixture is loaded and smelted with the ratio of the amount of aluminum to the stoichiometrically necessary for recovery of recoverable elements 1.7-3.5, the melt is aged for 0.1-0.6 times the second part of the mixture is melted, the high-alumina product is drained, then the remaining melt is loaded and a mixture containing 30-70% of titanium concentrate is smelted, with the ratio of the amount of aluminum to the stoichiometrically necessary for the recovery of recoverable elements 0.6-1.0 and the smelting products are drained. In addition, before discharging the smelting products to the melt, a fourth part of the charge is melted and melted in relation to the amount of aluminum to the stoichiometric amount required for the recovery of recoverable elements 1.7-3.0. In this case, alkali or alkaline-earth metal chlorides in an amount of 0.2-5 are added to the mixture, and the second and fourth parts of the mixture are injected from 2 to -20% of silicon oxides based on the weight of all aluminum for smelting. 4 When melting in the first stage of melting the mixture with a ratio of a specified amount of aluminum to the stoichiometrically necessary to restore the extracted elements (titanium, iron, silicon) equal to 0.9-1.3, slag is obtained with a higher content of titanium oxides than in the known nomu way. The specified ratio limits are due to the following. In the production of ferrotitanium is used as a titanium-containing material, in addition to titanium concentrates, metal waste of titanium and its alloys, loaded to the bottom of the smelting unit before melting. As the amount of titanium waste per smelting increases, the amount of aluminum in the charge increases so that the ratio of aluminum to titanium in the resulting alloy is approximately constant and in such a way as to prevent significant oxidation of titanium waste and its transfer into slag. Increasing the ratio of a given amount of aluminum to the stoichiometrically necessary for the recovery of recoverable elements above 1.3 is inappropriate because, with a slight increase in the extraction of titanium, a significant part of aluminum goes into metal and practically does not participate in the further reduction of titanium. In the second stage of the process, the goal is to maximize the recovery of titanium from the charge and slag produced in the first stage of the process, and to obtain slag with a low content of titanium oxides, which can be used as a commercial high-alumina product. This is achieved by penetration of the charge with a large excess of aluminum and discharge of the obtained slag from the smelting unit. The resulting alloy with a high aluminum content has a density lower than that obtained in the first stage, and therefore, located on its surface, does not mix with the base alloy for some time. As a result, an equilibrium is established for the reduction reaction of titanium from an oxide melt, in which for some time not the whole mass of the metal is involved, but only the newly formed layer with a high content of reducing agents, and, as a result, the titanium content in the melt decreases. In addition, the first melting of the charge with a deficiency or with a small excess of aluminum, and then the charge with a large excess of aluminum allows to significantly increase the extraction of titanium compared with the melting of both parts of the charge together (mono charge). When the monolith is melted, first of all, the reduction of oxides, iron from titanium concentrate and iron ore, which is set in charge, is primarily carried out. The formed iron drops, enriched with aluminum, are lowered onto the bottom of the smelting plant, as a result of which a significant amount of aluminum is practically not involved in the further process of titanium reduction. When the charge with a shortage or a slight excess of aluminum is first melted, the resulting slag contains almost no iron oxides, which creates favorable conditions for the reduction of titanium from it with aluminum, given in excess by the second part of the mixture. At the ratio of a given amount of aluminum in the mixture to stoichiometrically necessary for the recovery of recoverable elements less than 1.7, the required degree of titanium reduction and obtaining slag of the required quality is not achieved. An increase in the ratio of more leads to the formation of an alloy having a low density due to the high aluminum content. In this case, its amount is significantly entangled in the slag, which degrades the quality of the high-alumina product. In addition, the high aluminum content in the base metal creates difficulties in refining it from aluminum in the next stage. The holding of the melt before the slag is drained is necessary for the precipitation of the formed alloy from the slag and the formation of a protective layer. A delay of less than 0.1 times the penetration of the second part of the mixture does not both ensure the complete precipitation of the alloy droplets and the formation of a protective layer in which the reducing agents have an increased activity, holding more than 0.6 times the penetration due to dissolution of the protective layer in the main alloy, reducing activity reducing agents in the layer at the metal – slag boundary, and, as a consequence, to the transition of titanium from alloy to slag. In addition, prolonged exposure leads to a sharp cooling of the melt, which complicates the penetration of subsequent parts of the charge and the complete discharge of slag and metal from the melting unit. By melting in the third stage of the charge with low aluminum content (the ratio of the amount of aluminum to the stoichiometrically necessary for the recovery of recoverable elements is 0.6-1.0), the goal is to refine the alloy obtained at the previous stages from aluminum and obtain a standard metal. When the ratio of the amount of aluminum in the charge to the stoichiometrically necessary for the recovery of recoverable elements is less than 0.6, the specific heat of the combustion process of this part of the charge is reduced so that the temperature of the products of the reduction reactions decreases by 80-LLP C, which in turn leads to a sharp shift of the reduction reaction titanium and the side of formation of the initial substances, with a ratio of more than 1.0, the degree of refining of the alloy and the production of g standard aluminum content of the alloy are needed. The penetration before the discharge of products of melting of the charge with a high aluminum content (the ratio of a given amount of aluminum to the stoichiometrically necessary for the recovery of recoverable elements of charge 1) makes it possible to additionally extract titanium from the final slag and turn the slag into a commodity high-alumina product. The content of titanium oxides in this product is slightly higher than in the second part of the mixture obtained after melting, since with an increase in the mass of the metal in the smelting furnace and an increase in its temperature by the end of the refining period, the formation of a protective layer is difficult for a sufficient time, but significantly lower than in slag, obtained by a known method. With the ratio of a given amount of aluminum to the stoichiometrically necessary to restore the recoverable elements of the mixture 1} 1.7.7 times the extraction of titanium is low and the content of titanium oxides in the slag practically does not decrease, with a ratio of over 3.0 a significant amount of aluminum goes into an alloy which does not allow to obtain standard aluminum alloy. Example 1. (known). 500 kg of titanium waste is loaded into a stationary inclined forge, and the mixture of powder components of the following composition is smelted; kg of titanium concentrate, 350 kg of lime; 2100 kg of aluminum in vorichny} 0 kg of ferrosilicon (LC 75). After the completion of the smelting, an iron-thermal precipitator is set on the slag surface (280 kg of iron ore, 110 kg of secondary aluminum; YO kg of lime; 20 kg of ferrosilicon), and then a part of the slag is poured into a cast iron non-lined me- chanal receiver to form a garnish on its walls. After the first discharge, the remainder of the charge (1800 to titanium concentrate; 150 kg izvat; 900 kg alyumini secondary; 30 kg ferrosilicon) and iron-thermal precipitator (120 kg iron ore 45 kg alumina secondary; 50 kg lime; 5 kg ferrosilicon) after which the complete melting of the products of the melt into the metal receiver is carried out. As a result of smelting, standard ferrotitanium and slag containing 15, TU are obtained. The extraction of titanium from the concentrate and waste is 73. Slag cannot be used as a salable alumina product of VHC clinker (synthetic intermediate slag) due to the high content of titanium oxides. Example2. At the bottom of the stationary tilting furnace, 500 kg of titanium waste is loaded and the mixture of the following composition is smelted: 1800 kg of titanium concentrate; 800 kg of iron ore; 20 kg of ferrosilicon (FS 75); 20 kg sodium chloride; 500 kg of lime and 1200 kg of aluminum recycled; (relation to the stoichiometrically necessary amount of aluminum 1,1). After the first part of the charge has been melted, a furnace containing 200 kg of titanium concentrate, 35P kg of iron ore, is set on the furnace hearth; 200 kg of quartzite; 200 kg of lime; 50 kg ferrosilicon -. 08 55 kg of sodium chloride; 830 kg of recycled aluminum (ratio to the stoichi-h is the geometrically necessary amount of aluminum 2.5). The melting time of the second part of the mixture is 5 min. Having kept the melt in the furnace in the course of 30 seconds, the slag of the following composition is poured: D: TiO, 6,3; SiOti 1.7; 70.0; CaO 19;;, MgO 2.0; FeO 0.6. After that, the remaining melt in the furnace melts the mixture containing ijOOO kg of titanium concentrate; 500 kg of iron ore; 650 kg of lime-, 40 kg of ferrosilicon; 0 kg of sodium chloride, kg of recycled aluminum (relative to the stoichiometrically necessary amount of aluminum is 0.78). Then, a mixture containing 200 kg of titanium concentrate, 350 kg of iron ore, is loaded onto the melt and melted; 200 kg of quartzite; 250 kg of lime 50 kg of ferrosilicon 55 kg of sodium chloride and 830 kg of secondary aluminum (ratio to the ethiometrically necessary amount of aluminum is 2.5). After completion of the last mixture melting, standard ferrotitanium and slag containing I: TlOrj 9.8; SiOii 1.4; Alrj, 0 b9, 17.4; MgO 1,2; FeO 0.5. The total extraction of titanium from the concentrate and waste is 80.4% smelting. Example 3: Melting as in Example 2, but the ratio of the amount of aluminum to the stoichiometrically necessary for the recovery of recoverable elements in the first part of the charge is 0.8 (a) or 1.4 (b): a) slag , fused after the second part of the mixture, contains: TiOr | 8, 2; SiO 1.6; ,five; CaO 18.7, MgO 2.1; FeO 0.9; the final slag contains: TiO 10.0; SiO "1.0; 70.1; CaO 17.1; MgO 1.3; FeO 0.7, the total extraction of titanium from the concentrate and waste is melted at 77.0, b) the slag that has been drained after the second part of the mixture contains,%: TU 6.1; SiOii 1.3; A1 (0 71.0; CaO 18.9; MgO 1.8; FeO 0.9; final slag contains TIOQ 9.9; SiOij II; ACO 70.0; CaO 17.3; MgO 1.2; FeO O , SI; the total extraction of titanium from the concentrate and waste is 80.5 smelting. Example 4: Melted as in Example 2, but the ratio of aluminum to stoichiometrically necessary to restore recoverable elements in the second part of the charge equal in one of the heats 1.5Ca in the second - 3.8 (6): a) the slag is drained after the second part of the charge, contains D: TiOn 8j5; SIO 0.9; 68.7; CaO 19.3; MgO 2.0; FeO 0,6-, the final slag contains D: TtO (i9,8, SiOi 1,2;, 70,1; CaO 17,5; MgO 1,0; FeO 0,4; the total extraction of titanium from the concentrate and waste is in smelting 77.1, b) the slag that has been drained after the second part of the charge contains a large amount of metal cores and cannot be used as a high-alumina product, the final slag contains D: TtOi 9.6; SiO / j 0.8; Al (iO 70.2; CaO 17.5; MgO 2.1; FeO 0.8; total extraction of titanium cannot be determined. A3 and measure 5. The mixture is smelted as in Example 2, but the ratio of the specified amount aluminum to the stoichiometrically necessary in the second part of the charge is 3.2. The slag that has been drained after the second part of the charge contains: TiOij, 8; SiOf 1.7; 71.5; CaO 19; MgO 2.0; FeO 0 , 6. The final slag contains,.%: TU 10.0; SrOii 0.9;, 70.0; CaO 17.1; MgO, k, FeO 0.6; Total extraction of titanium from the concentrate and waste is melted 83.0. EXAMPLE 6 The mixture was melted as in Example 5, but the melt was aged in the furnace before the slag was discharged after the second hour. and the charge is equal to one of the heats of fusion of time from 0.06 second part of the charge (a) and 0.7 Sat) :. a) the second Part of the mixture is smelted for a minute, the melt is kept for 12 s, after which the slag is drained; the slag block contains a large number of crowns in its lower part, which constituted 1/3 of the total mass; slag contains,%: TiOj 4.9; SiO 1.5; ACO 71.0; CaO 20.0; MgO 1.7; FeO 0.9; the final slag contains,%: 9,7; 1.1; A1.0 70.2; CaO 17.0; MgO 1.5; FeO 0.5; total extraction of titanium from concentrate and waste cannot be determined; b) the second part of the charge melts for 4 minutes 30 C; after the second part of the charge is melted, the melt is kept for 3 minutes and 10 seconds, after which the slag formed on the melt surface remains in the furnace; merged slag contains,%: 5.3; SIO (iO, 4; AlijOj 70.8; CaO 19.5; MgO FeO 1.0; final slag contains A: TiOi 9.8; SiOn 0.9; AlijOj 70.1; CaO 17.5; MgO 1.2 ; FeO 9.5i, the total extraction of titanium from the concentrate and waste is 82.3%. Example 7 The mixture is smelted as in Example 5, but the ratio of a given amount of aluminum to the stoichiometric required for the recovery of recoverable elements in the third part of the mixture 0.5 (e) or 1.1 (6): a) the slag that has been drained after the second part of the charge contains,%: T} 0i2 5.5; SiO I; Al), 7; CaO 20.2; MgO 1.8, FeO 0.9; the final slag contains TiOij 12.3; 510.1.0; 67.5; CaO 17.6; MgO FeO 0,6-i cannot be used as a high-alumina product; The total extraction of titanium from concentrate and smelting waste is 79.3. b) the slag merged after the second part of the mixture contains: TiO, 8; 510 1.6; 71.3; CaO 19.8; MgO 1.9; FeO 0.6; the final slag contains, i: TiO (j 8.5; SiOij 0.9; Al, jp. 70.1; CaO 18.0; MgO 1.6; FeO 0.5} the metal with no aluminum content does not meet the requirement of the standard ; the total extraction of titanium in the smelting is 83.8%. EXAMPLE 8. The mixture is smelted as in Example 5, but the ratio of a given amount of aluminum to the stohyometrically necessary; The solid part of the mixture is equal to one of the heats 1 , 6ta), in the other - 3.2 (6): a) slag, fused after the second part of the charge, contains,%: TU 5.0; , 6; Al ,, 7; CaO 19.2; MgO 2.0; FeO 0.5; final slag content,%: TiO (i 13.3; $ S (I, I; ABO. 67.0; CaO 17.0; MgO 1.0; FeO O, and cannot be used as a high alumina product) total extraction of titanium in smelting it is 78.5. b) the slag that has been drained after the second part of the charge contains,%: TiO, 9; 510 1.5; AlaOj 71.0; CaO 19.5; MgO 2.3; FeO 0.8; the final contains:

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no 8.0; SlOii1,4; 70.6; Catt 17; MgO 1.8; FeO 0.8; the metal contains 1 (, 1% aluminum and does not satisfy the requirements of the standard; the total extraction of titanium on smelting is 84.6%.

The results of the experimental heats are shown in the table.

As can be seen from the table in the production of ferrotitanium on the proposed

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the method dramatically increases the extraction of titanium from the charge and, simultaneously with standard ferrotitanium, a high-alumina product is obtained.

The proposed method for the implementation does not require additional costs and can be implemented on existing equipment. The savings from the implementation of the proposed method is RUB. per year at the same factory.

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Claims (2)

S 15 Claim 1. Method for aluminothermic production of ferrotitanium, including loading, penetration of the mixture containing titanium concentrate and aluminum and production of smelting products, in order to produce ferrotitanium and high-alumina alumina of the product, an increase in the extraction of titanium, first smelt a mixture containing 20–50% of the titanium concentrate from its total mass for smelting at the ratio of the amount of aluminum to stoichs metrically necessary for the recovery of recoverable elements from their oxide in 0.9-1.3, then charge the mixture is smelted with the ratio of the amount of aluminum to the one hundred percent necessary for the recovery of recoverable elements 1.7-3.5, the melt is aged for 0.1-0.6 times the second part is melted The mixture is drained of a high-alumina product, then the remaining melt is charged and a mixture containing 3070% of titanium concentrate is smelted, with the relative amount of aluminum to the stoichiometric required to restore recoverable elements of 0.6-1.0, and the smelting of melts is discharged. 2, Pop. 1, characterized by the fact that before discharging melting products to the melt, the fourth portion of the charge is loaded and melted with the ratio of aluminum to stoichiometric required to restore recoverable elements 1.73, 0. .. 3. Method according to claim .1 and 2, characterized in that alkali or alkaline earth metal chlorides are added to the mixture in an amount of 0.2-51, and from 2 to 20% of silicon oxide from the mass of total aluminum is introduced into the second and fourth parts of the mixture. . Sources of information taken into account during the examination 1. USSR author's certificate ff 386019, cl. C 22 V, 197. 2. Ignatenko G.F. et al. Metallothermic processes in chemistry and metallurgy. Novosibirsk, Science, 1971, p.219.