WO2013070121A1

WO2013070121A1 - Pyrometallurgical red mud processing method

Info

Publication number: WO2013070121A1
Application number: PCT/RU2012/000946
Authority: WO
Inventors: Анатолий Анатольевич ГОЛУБЕВ; Юрий Александрович ГУДИМ
Original assignee: Общество С Ограниченной Ответственностью Промышленная Компания "Технология Металлов"
Priority date: 2011-11-07
Filing date: 2012-11-16
Publication date: 2013-05-16
Also published as: RU2479648C1; IN2014MN01026A

Abstract

The invention relates to the pyrometallurgical processing of red mud. Red mud is melted in an oxy-fuel skull melting unit, iron is reduced with a carbon reducing agent, and the metal and slag are discharged separately. The mud is additionally heated and dried in a drying device to a moisture content of 6-10% using heat from the melting unit flue gases having a temperature of 1750-1850°С, with lime production waste in the amount of 3-6% of the mass of the mud being added to the wet red mud. The dried mud is fed using an airtight feeding device from the drying device into the melted slag, which is heated to a temperature of 1640-1680°С, at a rate of 1.2-1.4 tonnes to 1 m2 of the surface of the melted slag per hour. Iron is reduced from the melted furnace charge using carbon-containing materials which are fed into the slag in an amount that ensures an iron oxide content of 3-5% in the reduced final slag. The separate discharge of the melting products is carried out continuously or intermittently with the fluctuations in the level of the melt in the melting unit being maintained at not more than 200-300 mm through the adjustment of the discharge rate and the amount of melting products. The result is a highly productive continuous, single-stage process for processing red mud and a simplification of the processing process.

Description

Method for pyrometallurgical processing of red mud

The invention relates to metallurgy and can be used for the efficient processing of red mud, by-products of the production of alumina.

Aluminum production inevitably causes the formation and accumulation of a large amount of red mud, a by-product of the processes for producing alumina. Red mud is a finely divided substance, an environmentally harmful product containing a large amount of alkali NaOH and up to 50% moisture. By traditional methods, the moisture content in red mud can be reduced only to 25%. Storage of red mud in special sludges requires significant costs, constant monitoring of the state of sludge storages and poses a serious danger to the surrounding territories.

At the same time, red muds contain a significant amount of iron oxides (up to 55%), comparable with the content of iron oxides in medium-quality iron ores. In addition, red mud contains a significant amount of titanium oxides, quite a lot of alumina A1 ₂ 0z. Therefore, the processing of red mud with the extraction of its useful components, primarily iron, can be cost-effective.

Large-scale processing of red mud can be carried out by hydrometallurgical and pyrometallurgical methods. Known hydrometallurgical methods for processing red mud are quite difficult to implement, inefficient, inevitably lead to the formation of secondary hazards, and for complete and final processing of the mud should be combined with pyrometallurgical methods. [one].

Pyrometallurgical methods for processing red mud have a number of advantages, the main of which is the possibility of practically waste-free processing of mud, with the receipt of marketable products that are in demand on the market. The disadvantages of pyrometallurgical methods for processing red mud are the need to use coolants to maintain the high temperature of the process and, most importantly, the need to dry the red mud (lowering the humidity to 10%) before loading into the melting unit.

Known methods of processing red mud by adding sludge to the mixture for the production of iron ore sinter, used in the smelting of pig iron in blast furnaces [2, 3, etc.]. These methods include the introduction of a small amount of red mud into the charge for the production of agglomerate and cannot solve the problems of large-scale processing of red mud. In addition, the delivery of red mud from storage facilities to sinter plants of ferrous metallurgy plants is very difficult and expensive.

Known methods for the disposal of red mud by a two-stage process [1, 4, etc.]. In this case, two units are provided for the processing of sludge. In the first unit (usually a rotary drum furnace), solid-state reduction of iron from red mud is carried out. In the second melting unit, iron is reduced and the metal and slag components of the product metallized in the first unit are separated. These methods have serious disadvantages that limit the possibility of their wide industrial application:

- before metallization in the first unit, the red mud must be pelletized, having received pellets, such a process is expensive and inefficient;

- the unit for solid-phase reduction of iron from red mud is large and small in productivity;

- it is difficult to coordinate the operation of the solid-phase reduction unit and the melting unit.

Known methods [5-9], involving the processing of a mixture containing red mud, in one unit, which is used first as an aggregate for solid-phase reduction of iron from a mixture, and then as a melting unit for the separation of the obtained metal and slag. Common disadvantages of these methods are: - a complex technological scheme of processing a mixture containing red mud, difficult to implement in real industrial conditions;

- low productivity of the proposed processes for processing red mud;

- a complete lack of information on the proposed scheme for drying red mud, while the use of wet red mud in the proposed methods is impossible without lowering the moisture content of the red mud to at least 10%.

These shortcomings almost completely exclude the possibility of effective practical implementation of the proposed methods for processing red mud in industrial conditions.

There is a known [8] method for processing red mud of alumina production (patent RU 2245371), selected by the applicant as the closest analogue of the claimed method.

In the known method, including preparing a portion of the charge containing red mud and a carbon reducing agent, heating the mixture in the melting unit to a temperature of solid-phase reduction of iron, solid-phase reduction of iron oxides in the mixture with a carbon reducing agent and saturation of iron in the prepared charge with carbon, melting the reduced mixture to obtain a metal phase in the form of cast iron and slag phase in the form of primary slag, the separation of cast iron from primary slag in the obtained melt heated to 1400 ° C, reduced the reduction of silicon and titanium from the aluminum oxides contained in the primary slag, the removal of cast iron and primary slag from the smelting unit, an addition to the red mud is provided for the preparation of a portion of the charge of a titanium magnetite ore concentrate containing from 1 to 15% titanium, as well as an additional amount of a carbon reducing agent and other materials. After the primary slag is separated from the metal in the melting unit, the cast iron is heated to 1500-1550 ° C, a product containing iron oxide is added to it, from which iron is reduced by carbon of cast iron to convert cast iron to steel to obtain secondary slag. Then the main part of the steel is removed from the smelter, the secondary slag is added to primary, of which silicon and titanium are transferred to the remainder of the steel in the smelter by reduction with aluminum to obtain the final slag and ligature containing iron, titanium, silicon saturated with aluminum (obviously, aluminum oxide). The main part of the ligature is removed from the smelting unit, after removal of the final slag, the titanium and silicon of the ligature residue are oxidized and the next portion of the recovered charge is fed into the slag phase formed after the ligature residue is converted to steel.

In addition, the preparation of a mixture containing a concentrate of titanomagnetite ore, a carbon reducing agent and additives is performed by pelletizing. As additives, crushed limestone and bentonite are used. In the future, as a product containing iron oxide, red mud or titanomagnetite concentrate, or iron oxide of rolling and forging production, or iron ore is used.

In addition, the final slag saturated with alumina is removed from the unit after the central part of the hearth of the melting unit is freed from ligature, carried out by rotation of the ligature residues by the electromagnetic field.

In addition, the transfer of the ligature residue into the slag phase of titanium and silicon is carried out by purging with air and / or oxygen supplied through sacrificial iron tubes.

The next portion of the recovered charge is fed into the slag phase formed after the transfer of the ligature residues to steel, which is rotated in the melting unit by an electromagnetic field.

In addition, after the reduction of silicon and titanium by aluminum from primary and added secondary slags, the newly formed final slag is cooled and aluminum oxide is separated from it by transferring it to the liquid phase by soda leaching to form a precipitate containing calcium and rare-earth metals. The precipitate is treated with hydrochloric acid to obtain a precipitate containing a concentrate of rare earth metals. A known method of processing red mud of alumina production has the following disadvantages:

- does not contain information or recommendations on the organization of the drying process of red mud, without which pyrometallurgical processing of red mud is impossible;

- to carry out solid-phase reduction of iron from the charge in the melting unit is irrational, because such a unit is structurally not suitable for solid-phase recovery, and the performance of the melting unit during this operation will be very low;

- to restore silicon and titanium from primary slag with aluminum is very expensive, especially considering the fact that in the future the technology recommended by a known method leads to the oxidation of reduced silicon and titanium from cast iron;

- obtaining steel of the desired composition from cast iron in a smelter by oxidizing carbon with additives of materials containing iron oxides is a difficult and inefficient process, especially considering the presence of silicon and titanium reduced from primary slag in cast iron, which will inevitably be oxidized before carbon cast iron;

- add secondary slag in the smelter to the primary slag (it is not known where this slag was previously removed from the smelter) is not beneficial, since in this case, primary slag with a low content of silicon and titanium oxides is mixed with secondary slag, containing a large amount of silicon oxides and titanium;

- the method does not explain how, in a subsequent production cycle, the recovered charge (where was it recovered in another unit?) is fed into the slag phase formed after the remnant of the ligature is transferred to steel;

- to obtain steel from cast iron is more profitable in the steelmaking unit by mixing cast iron with scrap;

- in general, the known method is very complicated. Technologically and organizationally, it does not allow solving the problem of mass and cost-effective processing of red mud.

The proposed method of pyrometallurgical processing of red muds solves the problem of creating a process of high-performance and efficient processing of red muds.

The technical result of the proposed method for pyrometallurgical processing of red mud is the elimination of the disadvantages of the closest analogue, namely:

- the creation of an effective and high-performance technology for drying red mud;

- the creation of a high-performance continuous single-stage process for processing red mud;

- Organization of an economical and high-performance process of liquid-phase reduction of iron in a skull melting unit;

- the exclusion of expensive complex and repetitive operations to re-restore aluminum slag, previously reduced carbon;

- solving the problem of mass and economical processing of red mud.

The technical result is achieved by the fact that in the method of pyrometallurgical processing of red mud, including the melting of red mud in a fuel-oxygen skull melting unit, the reduction of iron with a carbon reducing agent, the separate release of the obtained metal and slag, according to the invention, the red mud processing carried out in one stage further includes heating and drying the sludge in the drying device to a moisture content of 6-10% by heat of the gases leaving the smelting unit with a temperature of 1750-1850 ° C, into the drying the device to the wet red mud add 3-6% by weight of the sludge of lime production waste containing%:

CaO - 12-15; Si0 ₂ - 15-19;

A1 ₂ 0 ₃ - 4-5;

Fe ₂ 0 ₃ - 1.5-2.0;

CaC0 ₃ - 56-62,

dried red mud with a pressurized loading device is loaded from the dryer onto molten slag obtained during the processing of sludge heated to 1640-1680 ° C at a rate of 1, 2-1.4 tons per 1 m ^{2 of} molten slag mirror per hour, iron recovery from the molten mixture is produced with carbon-containing materials loaded onto the slag in an amount ensuring the content of iron oxides in the reduced final slag in the range of 3-5%; separate discharge of the melting products is carried out continuously or periodically, supporting fluctuations in the level of the melt in the melting unit by no more than 200-300 mm due to changes in the drain rate and the amount of smelting products.

In addition, carbon monoxide CO exhaust gases from the smelting unit is used for partial solid-state reduction of iron.

In addition, the content of iron oxides in the reduced slag is adjusted by changing the amount of gaseous oxygen supplied to the fuel-oxygen burners at a constant flow rate of the carbon reducing agent.

In addition, the melting and heating of the charge materials loaded into the melting unit is carried out due to the heat obtained by oxidizing the carbon materials introduced in the required amount with gaseous oxygen, injected with water-cooled lances into the melting unit at a supersonic speed.

In addition, the dried red mud is injected into the melt in the melting unit by injectors.

In addition, the processing of red mud is carried out in a continuous fuel and oxygen skull melting unit with cooling of the metal body of the unit with a liquid metal coolant. In addition, 35-45% of the used carbon reducing agent is loaded into the drying unit together with red mud.

In addition, the reduced low-iron slag is poured from the smelter into an arc furnace with a carbon lining of the bath and a complex alloy Fe-Si-Al-Ti and calcium-aluminum slag are obtained from it by carbon thermal reduction.

The implementation of the processing of red mud in one stage can significantly increase the performance of the smelter and simplify the processing technology.

The heating and drying of red mud to a moisture content of 6-10% with the exhaust gases from the smelter at a temperature of 1750-1850 ° C makes it possible to safely process sludge without fear of explosion when wet sludge enters the molten heated slag, and also significantly increase the thermal efficiency of the unit. Drying red mud to a moisture content of less than 6% causes a decrease in the productivity of the drying device and will require a significant increase in the size and, accordingly, the cost of the drying device. A moisture content in the loaded red mud of more than 10% can lead to an explosion when it is processed in the smelter.

When the temperature of the gases leaving the melting unit is less than 1750 ° C, and therefore the same temperature of the gases in the working space of the melting unit above the melt, it is possible to heat the slag melt and reduce the speed and completeness of iron reduction from the molten sludge.

Obtaining an exhaust gas temperature of more than 1850 ° C requires increased fuel and oxygen consumption, and also increases the heat loss of the unit through the housing.

The use of carbon monoxide СО of the exhaust gases for partial solid-phase reduction of iron during heating and drying of red mud reduces the consumption of carbon reducing agent and increases the productivity of a smelter that processes red mud. The additive before loading into the drying device to the wet red mud 3-6% by weight of the sludge of lime production waste containing,%: 12-15 CaO, 15-19 Si0 ₂ , 4-5 A1 ₂ 0 ₃ , 1,5-2, 0 Fe ₂ 0 ₃ , 56-62 CaCO3, facilitates the drying of sludge, reduces the removal of dust from the drying device and some reduction in the melting temperature of the recovered final slag of the process and, accordingly, increase its fluidity.

The addition of waste lime production in an amount of less than 3% by weight of red mud does not give a sufficient (due) effect.

The addition of lime production waste in an amount of more than 6% significantly reduces the performance of the smelting unit and degrades the mechanical properties of the hardened final slag as a result of an increase in its basicity.

The loading of dried red mud from the drying device into the melting unit on molten slag obtained during the processing of sludge heated to 1640-1680 ° C at a speed of 1.2-1.4 tons per 1 m ^{2 of} molten slag mirror per hour provides the highest speed penetration of sludge and reduction of iron from it.

When the molten slag is heated to a temperature of less than 1640 ° C, the melting rate of the loaded sludge and the rate and completeness of iron reduction are reduced, which leads to a decrease in the productivity of the smelter and a decrease in the performance of the red mud processing.

When the molten slag is heated to a temperature above 1680 ° C, the heat losses of the unit and fuel consumption for the process increase. At the same time, there is no noticeable improvement in the process indicators due to an increase in the rate and completeness of iron reduction, since iron losses increase due to evaporation in the contact zone of the fuel-oxygen burner torches with the melt.

When loading dried red mud (charge) into the melting unit on molten slag at a rate of less than 1.2 tons per 1 m ² melt mirrors, unit performance decreases, slag overheating and increase in heat losses of the melting unit are possible.

When the charge loading speed is more than 1.4 tons per 1 m ^{2 of the} melt mirror, the loaded charge does not have time to completely melt and heat up to the required temperature. This leads to a decrease in the temperature of the slag melt, a decrease in the rate of iron reduction, makes it difficult to separate droplets of the reduced iron alloy from the slag, and worsens the performance of the red mud processing.

The loading of carbonaceous materials for iron reduction to the slag in such an amount that the content of iron oxides in the reduced final slag is within 3-5% increases the speed of the red mud processing and allows obtaining the final slag with high mechanical properties suitable for the production of building materials and slag products.

The content of iron oxides in the reduced final slag of less than 3% does not allow to obtain the necessary high mechanical properties of the slag and reduces the performance of the sludge processing process.

The content of iron oxides in the final slag of more than 5%, although it provides the necessary mechanical properties of the slag, leads to a deterioration in the performance of the sludge processing process as a result of a decrease in the yield of reduced iron in the form of cast iron (reduces the yield of cast iron from the processed sludge).

Correction of the content of iron oxides in the reduced final slag by changing the amount of oxygen supplied to the fuel-oxygen burners, at a constant flow rate of the carbon reducing agent, simplifies the technology, allows you to quickly and efficiently obtain the final slag of the desired composition with the desired properties.

Separate discharge of smelting products (cast iron and final slag) continuously or periodically at such a speed and in such an amount that the melt level in the melting unit does not fluctuate by more than 200-300 mm, which makes it possible to increase the resistance refractory lining of the metal bath and skull in the slag zone of the melting unit, which leads to improved performance of the sludge processing process.

Fluctuation (decrease) in the level of the melt in the melting unit when the melting products are released by more than 300 mm results in a significant amount of slag dropping into the metal bath and accelerating the wear of the refractory lining of the metal bath.

A decrease in the level of the melt in the melting unit when releasing melting products by less than 200 mm is possible only with a very low speed of release and a small amount of melted products being drained. This option is disadvantageous because it reduces the performance of the unit and reduces the temperature of the melting products in the casting ladles.

The processes of melting and heating of charge materials loaded into the melting unit due to the heat obtained by oxidizing the introduced solid carbon materials with gaseous oxygen, which are blown into the melting unit at supersonic speed by water-cooled tuyeres, can replace relatively expensive and in some places scarce fuel - natural gas, cheaper and non-deficient materials: coal or brown coal, as well as carbon-containing waste. This makes it possible to use the proposed invention in areas where there is no natural gas, and reduce the cost of processing red mud.

The injection of dried red mud by injectors into the melt located in the smelting unit makes it possible to simplify the scheme of loading sludge into the aggregate and reduce the capital costs of constructing the aggregate for processing red mud.

The implementation of the processing of red sludge in a continuous fuel and oil skull melting unit with cooling of the metal casing by a liquid metal coolant makes it possible to have the necessary high temperature of the melt, accelerate the reaction of reduction of iron from the melt, and facilitates separation slag and metal phases in the working space of the unit, ensures the formation of a slag skull on the working surface of the housing and provides the possibility of long-term continuous operation without stopping the unit to repair the lining of the working space.

The loading of 30-45% of the carbon reducing agent used in the drying unit together with the red mud ensures accelerated drying of the sludge due to the additional heat input during partial oxidation of the reducing agent, enhances the solid-state reduction of iron and improves the productivity of the melting aggregate.

Loading less than 30% of the carbonaceous reducing agent used in the drying unit gives only a slight increase in the drying rate of red mud.

The loading of more than 45% of the carbonaceous reducing agent used in the drying unit, although it increases the drying speed of the sludge, leads to a decrease in the total thermal efficiency of the red mud processing process due to a significant increase in heat loss with the gases leaving the drying unit, and also complicates the process of cleaning the exhaust gases.

The discharge of the reduced final low-iron slag from the smelting unit into an arc furnace with a carbon lining of the bath and the production of a complex Fe-Si-Al-Ti alloy and calcium-aluminum slag from it at high temperature by carbon thermal reduction allows for the waste-free processing of red mud to produce the most popular commodity products: cast iron in a smelting unit, a complex alloy of Fe-Si-Al-Ti and calcium-aluminum slag in an arc furnace. In this case, when processing red mud, no secondary industrial waste is produced and the unit operating costs for the production of marketable products are significantly reduced.

The essence of the claimed method is illustrated by the technological scheme. Figure 1 shows the technological scheme of the proposed method of pyrometallurgical processing of red mud.

The method of pyrometallurgical processing of red mud is as follows.

Red sludge with a moisture content of not more than 25% is loaded into the drying unit 1, to which wastes of lime production in the amount of 3-5% by weight of the sludge are added. Low-melting waste of ferrous metals (cast iron and steel shavings, pig iron, small steel trimmings) is loaded into the melting unit 2 through the loading hole 3 in the housing. The fuel-oxygen burners 4 are turned on and a liquid metal bath is deposited in order to prevent the refractory lining of the metal bath from being destroyed by the overheated slag melt. During the deposition of a metal bath, the gases passing through the loading hole 3 from the melting unit with a temperature of 1750-1850 ° C pass through the drying unit, as a result, the moisture of the red mud is reduced to 6-10%, in the high temperature zone in the drying unit of the exhaust gas СО solid-phase reduction of iron. After the metal bath is fused with a hermetic dosing charging device 5, the dried charge is loaded into the melting unit first on the metal and then on the formed slag melt at a speed of 1.2-1.4 tons per 1 m ^{2 of the} melt mirror per hour.

To restore iron and its carburization from the resulting slag melt, the slag heated to 1640-1680 ° C is charged with carbon-containing materials in the amount of iron oxides in the recovered final slag in the range of 3-5% through loading hole 3. If necessary, the content of iron oxides in the reduced final slag is adjusted at a constant consumption of the carbon reducing agent by changing the amount of oxygen supplied to the fuel-oxygen burners 4, droplets of the reduced iron are deposited from the slag melt 6 into the metal bath 7, carbonized during passage through the slag melt. In this case, the metal level in the metal bath increases. As accumulation in the melting unit, the resulting molten iron and the recovered final slag are separately poured from the melting unit through flight devices 8, 9 into cast iron 10 and slag-filling ladles 1 1 at such a speed and in such quantity that the melt level in the melting unit does not fluctuate by more than 200-300 mm. This allows you to increase the resistance of the refractory lining of a metal bath, to increase the productivity of the process of processing red mud.

Part or all of the dried sludge can be blown into the slag melt by injectors 12, the dust collected in the gas purification 13 is blown into the melt by the same injectors 13. A part (30-45%) of the used carbon reducing agent can be loaded into the drying device to accelerate the drying of the charge and improve the technical and economic indicators of the process of processing red mud.

The proposed method for processing red sludge is carried out in a continuous fuel-oxygen skull melting unit 2, the body of which is cooled by a liquid metal coolant in order to increase the continuous operation of the melting unit and reduce the consumption of refractories. In the absence of natural gas, the melting and heating of the charge materials loaded into the melting unit is carried out due to the heat obtained during the oxidation of solid carbon-containing materials introduced through the loading hole 3 by gaseous oxygen injected into the melting unit at a supersonic speed by water-cooled tuyeres 4.

In order to improve the economic performance of the process, the recovered final low-iron slag is poured from the smelter into an arc furnace with a carbon lining of the bath and, at high temperature, the complex Fe-Si-Al-Ti alloy and calcium-aluminum slag are obtained from it by carbon thermal reduction.

Examples of specific implementation, confirming the possibility of implementation of the proposed method. Example 1

Crucibles with a charge of different composition were put in a heating laboratory furnace in accordance with the proposed method (300 g of red mud each with a moisture content of 25% in the charge), exposure was performed for 90 seconds, then crucibles with a charge were taken from the furnace and the moisture content in the charge was determined by decreasing masses. Conducted 3 experiments of each option. The results of laboratory experiments are shown in table 1.

Table 1.

The above results indicate an acceleration of the drying process of the charge when a small amount of lime production waste or lime production waste and a small amount of carbon reducing agent are added to the red mud.

Example 2

In an arc steelmaking furnace ДС 1.5 with a capacity of 1.5 t, with a bath diameter of 1.5 m, and a melt surface area of 1.76 m ^{2, a} mixture consisting of dry red mud (humidity 9.5%), additives of lime waste and the required amount of carbonaceous reducing agent - coke, the same for all swimming trunks. Smelting was carried out with different melt temperatures and different rates of charge loading into the furnace.

The results of the experimental swimming trunks are shown in table 2. Table 2.

The results of experimental swimming trunks for processing red mud presented in table 2 confirm the influence of the melt temperature and charge loading rate on the rate and completeness of reduction of iron from red mud, as well as the efficiency of the process parameters proposed by the proposed method.

Example 3

The possibility of heating and melting the mixture due to the heat released during the oxidation of carbon materials loaded into the melting unit with gaseous oxygen introduced into the working space by water-cooled tuyeres is confirmed by the results of semi-industrial and industrial experiments described in [10, P].

Literature

1. L.I. Leontiev, N.A. Vatolin, SV. Shavrin, N.S. Shumakov. Pyrometallurgical processing of complex ores. - M. “Metallurgy”. 1997 .-- 432 p.

2. A.S. USSR SU 1770412 A1. Applicant: Zaporizhzhya Industrial Institute. Authors: A.I. Amosenok, N.F. Kolesnik, S.S. Kudievsky.

3. Patent RU 2016099 C1. A method of producing iron ore sinter. Authors: Petrov SI., Utkov V.A., Bytkin V.N., Krymov G.P., Bastryga I.M., Nikolaev SA. Patent holder: OJSC All-Russian Aluminum and Magnesium Institute. 4. AC USSR SU Al. Applicant: Institute of Metallurgy, Ural Scientific Center, USSR Academy of Sciences. Authors: V.A. Kiselev, L.I. Leontiev, G.N. Kozhevnikov, L.I. Permyakova.

5. Patent RU 2086659 C1. A method of processing iron-alumina raw materials. Authors: Burkin SP., Loginov Yu.N., Korshunov EA, Zhukov SS, Shchipanov AA, Nalesnik VM Patent holder: Closed Joint-Stock Company White Sable.

6. Patent RU 2179590 C1. The method of disposal of red mud is a waste of alumina production. Author: Schukin B.C. Patentee: Schukin B.C.

7. Patent RU 2165461 C2. Method for the production of pig iron and slag. Authors: Korshunov E.A., Smirnov L.A., Burkin SP., Tarasov A.G., Loginov Yu.N., Sarapulov F.N. Patent holder: OJSC Ural Institute of Metals.

8. Patent RU 2245371 C2. A method of processing red mud of alumina production. Authors: Korshunov EA, Burkin SP., Loginov Yu.N., Loginova IV, Andryukova EA, Tretyakov B.C. Patent holder: Limited Liability Company “DATA-CENTER”.

9. Patent RU 2356955 C2. Authors: Pervushin N.G., Pervushina V.P. Patent holder: State educational institution of higher professional education “Ural State Technical University - UPI named after B.N. Yeltsin”.

10. V.A. Kudrin. Theory and technology of steel production. M. "The World". 2003 - 528 s.

11. The ROMELT process. Edited by V.A. Romance. M. "MISiS". Publishing House "Ore and Metals" 2005. 400 p.

Claims

F O R M U L A

1. The method of pyrometallurgical processing of red mud, including the melting of red mud in a fuel and oxygen skull melting unit, the reduction of iron with a carbon reducing agent, the separate release of the obtained metal and slag, characterized in that the processing of red mud, carried out in one stage, further includes heating and drying the sludge to humidity of 6-10% by heat of gases leaving the melting unit with a temperature of 1750-1850 ° С; before drying, 3-6% of m is added to the wet red mud to the drying device ssy lime sludge waste products containing%:

CaO - 12-15;

Si0 ₂ - 15-19;

A1 ₂ 0 ₃ - 4-5;

Fe ₂ 0 ₃ - 1.5-2.0;

CaCO3 - 56-62,

dried red mud with a pressurized loading device is loaded from the dryer onto molten slag obtained from the processing of sludge heated to 1640-1680 ° C at a speed of 1.2-1.4 tons per 1 m ^{2 of} molten slag mirror per hour, iron recovery from the molten mixture is produced with carbon-containing materials loaded onto the slag in an amount ensuring the content of iron oxides in the reduced final slag in the range of 3-5%; separate discharge of the melting products is carried out continuously or periodically, supporting I melt level fluctuation in the melting aggregate is not more than 200-300 mm by changing the discharge velocity and quantity of the fusion products.

2. The method of pyrometallurgical processing of red mud according to claim 1, characterized in that the carbon monoxide CO of the exhaust gases from the smelting unit is used for partial solid-phase reduction of iron.

3. The method of pyrometallurgical processing of red mud according to claim 1, characterized in that the content of iron oxides in the reduced slag is adjusted by changing the amount of gaseous oxygen supplied to the fuel-oxygen burners at a constant flow rate of the carbon reducing agent.

4. The method of pyrometallurgical processing of red mud according to claim 1, characterized in that the melting and heating of the charge materials loaded into the melting unit is carried out due to the heat obtained by oxidizing the carbon materials introduced in the required amount with gaseous oxygen, blown into the melting unit with supersonic water-cooled lances.

5. The method of pyrometallurgical processing of red mud according to claim 1, characterized in that the dried red mud is injected into the melt in the melting unit by injectors.

6. The method of pyrometallurgical processing of red sludge according to claim 1, characterized in that the processing of red sludge is carried out in a continuous fuel-oxygen skull melting unit with cooling of the metal case of the unit with a liquid metal coolant.

7. The method of pyrometallurgical processing of red mud according to claim 1, characterized in that 35-45% of the carbonaceous reducing agent used is loaded into the drying unit together with the red mud.

8. The method of pyrometallurgical processing of red sludge according to claim 1, characterized in that the reduced low-iron slag is poured from the smelter into an arc furnace with a carbon lining of the bath and a carbon-thermal reduction method produces a complex Fe-Si-Al-Ti alloy and calcium-aluminum slag.