WO2007075112A1 - Metal and alloy melting device - Google Patents

Abstract

The invention relates to metallurgy and can be used in processes for directly reducing iron from iron ores and/or from metal-containing wastes and in thermal engineering for producing slag articles. The inventive metal and alloy melting device consists of a cylindrical furnace, which is provided with a bottom and comprises a cooling system, slag and metal tapping refluxes, gas supply tuyeres, a loading unit and a waste-heat recovery system. Said cylindrical furnace is arranged in the combustion space of a boiler unit, which is provided with liquid slag removal, between the lower stage of the boiler unit burners and a lower collector of water-cooled screens.

Description

 Device for smelting metals or alloys

The invention relates to metallurgy and can be used in the processes of direct reduction of iron from ores and / or metal-containing waste, as well as in the power system for the production of slag products.

Known blast furnace. Its operation requires expensive and scarce coking coal, the reserves of which are exhausted. Therefore, the search for more advanced cast iron smelting technologies has gone along the lines of optimizing direct reduction of iron.

In direct reduction plants, solid iron ore is transformed into sponge or hot-briquetted iron, which also contains waste rock transferred from the ore. AT Depending on the type of reducing agent, direct reduction processes are divided into gas and solid phase. For gas-phase reduction in industry, shaft furnaces (Мdgeh, HyL Ш, Ageх), retorts (HyL Г) and fluidized-bed furnaces (Fiоr, Фіпмет, Ироп Сарбиде, СирСОред) are used; for solid-phase recovery, rotary tube furnaces (SL / RN, DRC) and rotary hearth furnaces (IPMETCO, FastMet, Drulrop).

Processes with a melting gas generator (Coex). In this process, we are talking about the conditional separation of the blast furnace into two parts; however, there is no need for a softening zone (or cohesion zone), which requires the presence of coke, which ensures gas permeability and “shell” of the charge column. The Coex process uses a lump mixture (pellets, ore). Obtaining reducing gas occurs during the gasification of lump coal with oxygen. The gas mixture from the melting gasifier, enriched with CO, is used to reduce iron ore to sponge iron in the mine. Direct iron smelting processes from ores or iron-containing wastes based on, for example, the Coex-process require an increased consumption of coal and oxygen blast (up to 1 ton of oxygen per 1 ton of metal) to compensate for the endothermy of iron reduction, i.e. require additional costs. Therefore, the main efforts of developers are aimed at their organized use. For example, in US Pat. No. 5,643,354, (C21B 011/00, 1997), an apparatus based on an ion-conductive high-temperature ceramic membrane that releases oxygen from flue gases to return it to the process is used to return oxygen to the process. In this case, the high-temperature gas stream after the membrane is used to generate electricity. All processes direct carbon monoxide reduction processes are low-temperature and multi-stage; therefore, additional equipment is required for implementation and, therefore, expensive.

The autogenous smelting process in a liquid bath is well understood and used in the production of non-ferrous metals. The heat source for the process is the oxidation of sulfides of raw materials during sparging of the melt with oxygen-containing gases. Heat is generated on the surface of the reacting particle or in the melt, i.e. where it is spent on melting processes. For these reasons, in autogenous processes occurring in suspension or in the melt, the charge is heated quickly and does not limit the performance of the melting units. The sulfide oxidation reactions proceed at the phase boundary very intensively and accelerate with increasing temperature. Sulfides are the most low-melting components of the charge of non-ferrous smelting, while their eutectic mixtures have even lower melting points. Therefore, the processes of matte formation begin earlier than the processes of slag formation and proceed at high speeds. Slag formation is slower because, for most batch oxides, the melting temperature is higher than the temperature in the furnace. The limited temperature capabilities of the melting units increase the importance of the processes of dissolution of refractory oxides in primary slag melts. But these processes are diffusion and for their acceleration and more complete extraction of the matte component, quartz flux is introduced into the slag melt, which, in turn, increases the slag multiplicity / A.V. Vanyukov, V.P. Bystroe, A.D. Vaskevich, V. H. Bruek, V. Ya. Zaitsev, I.I. Kirillin, A.A. Komkov, N.M. Mantsevich, N.A. Miklin, MJI. Sorokin, A.N. Fedorov, V.S. Cesarsky, A.G. Shubsky, Melting in liquid bath, Moscow, "Metallurgy", 1988 /.

An analogue of the non-ferrous process of melting in a liquid bath, in the iron and steel industry are liquid-phase reduction processes. Since the 50s of the last century, a constant search has been conducted for processes that constitute an alternative to the blast furnace process using elements of a color liquid-phase process.

The Dios process was developed in Japan by the Iron and Steel Federation and the Center for the Use of Coal with the support of the Ministry of Foreign Trade and Industry / Dios Process-Direct Irop Ore Sméltipg Revocoproces. Product Ipformatiop, Septer foral Utilisatiop, The Jarap Irop and Stel Federatiop, Jarap. 1994 / Preliminary studies (1988-1991) were conducted on a 100-ton experimental liquid-phase reduction reactor converted from a 170-ton converter at the plant of Niroprop Steel Corp., Sakai. For the first time, the process was implemented on a semi-industrial experimental installation with a nominal capacity of 180 thousand tons of cast iron per year in 1993 at the Keihin plant of NKK, Japan. At various times, eight Japanese steelmaking associations took part in the project.

The process is three-stage. It provides for the stage of preheating (up to 600 ⁰ C) of the fine ore mixture (less than 8 mm), then from the preheater the ore enters the prereduction reactor (diameter 2.7 m, height 8 m) in a fluidized bed at an operating temperature of ~ 780 ⁰ With carbon monoxide. From the pre-reduction reactor, the prepared raw materials are transported to the converter-type liquid-phase reduction reactor. The geometric dimensions of the characteristic zones in the working space of the Dios experimental reactor are: bath diameter 3.7 m, reactor height 9.3 meters. Temperatures: in a metal bath - 1500 ⁰ C; in foamed slag 1600-1650 ⁰ C; in the superlayer space 1700-1900 ° C. The disadvantage of this process is its multi-stage. Waste gas heat recovery can be carried out in a waste heat boiler, but it is not yet implemented, as requires the development and creation of a special design.

Нismеlt-process, Australia. Intensive research began in the early 1990s by Rio Tipo Corporation, which created the company of the same name to develop and market the Hismelt process and spent about 220 million dollars on technology development.

In 1997-1999. three long-lasting (up to 5 weeks) melts were successfully carried out at the Hismlt pilot plant (bath diameter 2.7 m) at the factory in Quipapa (pc. Western Australia).

The reduction of iron from slag is carried out by carbon dissolved in cast iron in a cylindrical vertical reactor connected to a metal sump by a flow located at the bottom. Slag discharge is organized from the bottom of the slag bath. In the upper part of the reactor, a fence is made of water-cooled panels, on which a slag skull is formed. The hearth and the lower part of the furnace wall are lined with refractory bricks.

The installation option Hismelt with a capacity of 600 thousand tons of pig iron per year is supposed to be implemented at the plant of a large American company Nucor Corr. An agreement was reached on this project between this firm and Lurgi Metallurgie, Germany, and Rio Tipto Ltd., United Kingdom - Australia. The developers of the process suppose to implement it in industrial plants with a bath diameter of 6 and 8 m / b ап p apd steel sopf. ("Scar Altiverptives") rero. Prodastiop apd us оf sсrar substitutеs, Steel Times, 1999. Joshie. P. 228-232, Masauleu D., Rice D, Нismеlt-а vеrsаtіlе hоt irop рrеss, Stеl Timеs Iptemаtiopl. 1999. Mau. P. 23-25, Dr R., Wates C, Rice D, Nismelt-tuture ip direst iropmakipg, ISTI / 58th Ironmaking Sopf. Roseyedipgs, Shishago, Illispois, USA, 1999. V. 58. P. 361-366 / The Нismеlt process is technologically well developed in a pilot installation. The declared technical and economic indicators of the Hismlt installations on the market with an annual capacity of ~ 0.5 million tons of intermediate product (reactor diameter 6 m) and 1.5 million tons of intermediate product (reactor diameter 8 m) are better than blast furnace indicators.

CCF - Suspop Support Fppass - process / Irop upd steel sopf. ("Scar Altiverptives") rero. Рrodastiop apd usе оf sсрар substitutеs, Steel Times, 1999. Jupe. P. 228-232 / has been developed since the beginning of the 90s by the Dutch company Nogoveps, under the auspices of the EU, supported by commercial organizations. In the CCF process cold cold ore, metallurgical dust, and dried sludge are tangentially blown in an oxygen stream and fed to a cyclone located directly above the liquid-phase reduction reactor. The slag bath in the reactor is purged with oxygen through a vertical submersible lance. Coal is fed to the slag from above. To improve the heat supply to the metal bath, a bottom nitrogen purge is provided.

The CCF process is the only one of the two-stage processes in which the exhaust gases from the installation have a sufficiently high temperature and are suitable for generating electricity.

Ausirαp - the process fully utilizes the principles of the Ausmelt process used in non-ferrous metallurgy. At the end of the 1990s, a pilot plant with a capacity of 2 t / h was created at the Whuall Steel Steel Works plant (Whua, South Australia). The project is currently being implemented with the support of the Government of South Australia as part of the Saut Australap Steel Apérprogram (SASE) Project. The main shareholder of the project is Ausirop Epergu Ltd. The first They received the metal at the pilot plant in November 2000; they achieved stable operation by February 2001.

In the Ausirop process, iron-containing oxidized materials are reduced in a bubble bath slag bath. Ground coal with a fraction of less than 1 mm is blown into the slag layer from above through water-cooled vertical tuyeres. Iron-containing raw materials with a particle size of 2-20 mm and lump coal are fed to the surface of the slag bath, in which iron is reduced by coal. Slag temperature 1400-1450 ⁰ C.

Romelt process Lop apd steel sopf. ("Scar Altemtives") rero. Prodastiop apusе оf sсрар substitutеs, Steel Times, 1999. Joshie. P. 228-232 / lead in a furnace with a bubbling slag bath. The furnace does not have moving parts and mechanisms in the high temperature zone, is simple in hardware design and is characterized by high operational reliability. The mixture, consisting of iron-containing oxide material, solid carbonaceous fuels, and flux (limestone, lime), is fed into the furnace to the surface of the slag bath from the bunkers through weighing batchers by a conveyor system without prior mixing. Drops recovered from metal slag are lowered onto the bottom of the furnace, forming a metal bath (temperature 1300-1450 ⁰ C). An oxygen-containing blast is supplied to the slag bath through the side tuyeres.

The Romelt installation has worked out the technology of smelting many types of iron-containing raw materials - ore, concentrates, dust, sludge, scale, steel shavings, there are real prospects for processing "red mud, waste sulfuric acid (pyrite cinder) and some other accumulated non-ferrous metal waste, for example slag from copper production. Zinc is almost completely goes into dust, which allows you to extract it in the form of marketable products.

Operation of the Romelt installation showed the possibility of stable, controlled operation of a fully liquid phase recovery unit. The chemistry of the process is similar to the domain one, with the only difference being that 85-90% (at a slag temperature in the surface and spray layer of a slag bath of 1500 - 1550 ⁰ C, respectively) of reduced iron occurs in a direct reduction reaction with coal particles. An increase in the process temperature by 100 ⁰ C increases the recovery rate by approximately

2 times The laws governing the control of the liquid-phase reduction process have been sufficiently studied.

Interest in the processes of liquid-phase metal reduction is not weakening. Today, there are already developments to produce ferroalloys and steel / B .M. Lupeyko, A new process for the direct production of steel by liquid-phase reduction of iron ore, Steel, Ns 9-2000. CM Tleugabulov, Theoretical provisions of the direct production of steel by reduction smelting, Steel N ° 8-2003 /. Semi-industrial tests for the processing of household waste in this way have been carried out.

Thus, the Romelt process is the most developed and universal process suitable for the processing of granulated slag and solid waste.

However, chemical reactions of direct reduction of oxides require energy costs significantly more than in the blast furnace / Tovarovsky IG, Comparison of fuel consumption in blast furnace and in the process of liquid-phase reduction Romelt, Steel N ° 12-1998 /. And the increase in the Romelt process temperature dramatically reduces the duration of the campaign due to lining wear. Large volumes of exhaust gases require large capital expenditures for the construction of gas treatment facilities.

These issues are all resolvable if the Romelt furnace is used as an energy technology unit in which the energy produced can be considered as an independent product. The prospects for this use are beyond doubt.

Thus, exothermic reactions of metallurgical processes can and should generate energy, but the existing metallurgical units for liquid-phase processes at temperatures of 1500-1550 ⁰ C maintain the process continuity of not more than 15-20 days, which is a big inconvenience for electricity generation. Existing units with ¹ refractory lining are not able to provide in due measure (at least 1 year) the duration of the liquid phase reduction process.

For these purposes, a specially designed unit is required that allows the metallurgical process to run smoothly and efficiently utilize the heat of this process. Attempts to increase the duration of the metallurgical process ended with the installation of a water-cooled fence (caissons) in the furnace at the level of the slag belt. This event allowed to slightly increase the service life of the unit, but did not solve the problem of long-term operation of the unit as a whole. Installation of water-cooled elements in the lower part of the unit (metal accumulation zone) is not permissible due to the danger of explosion in case of contact of molten metal with water.

A known melting furnace / RU 2067273, F27D1 / 12, 1996 /, which is cooled by a liquid sodium coolant. This technical solution allows to solve problems associated with an increase in the duration of the metallurgical process. A device for cooling and utilizing the heat of exhaust gases from the furnace / RU 2082929, F27D 17/00, 1997 /, which allows you to get additional heat to generate electricity by using steam generators such as sodium-water. However, the implementation of such devices is associated with the creation of a cumbersome and difficult-to-operate emergency protection system for steam generators from possible leaks of water into sodium, for example, due to local corrosion of the steam generator from the water (steam) side.

The most important advantage of using one or another coolant is safety in case of possible thermal interaction (in case of violation of the integrity of the separation wall) of molten metal with a cold coolant. In this case, a hot liquid (metal) can quickly fragment into small particles (drops) and transfer its internal energy to a colder and more easily evaporated liquid (water). As a result of evaporation, high pressure is generated (more than 200 atm), water decomposes with hydrogen evolution, which leads to corresponding destructive consequences. This problem exists in a number of industries: energy, metallurgy, production and transportation of liquefied gases, etc. Similar phenomena occur during volcanic activity during the interaction of water with hot magma. The interaction of sodium with molten steel (cast iron) is accompanied by the generation of steam, not bearing the nature of an explosion. Therefore, from the point of view of the interaction of the melt with the coolant, sodium has a huge advantage over water and can be used to create a long-acting melting unit without traditional massive refractory lining.

Such a sealed, stationary unit power plant, is provided by systems: continuous loading of raw materials; supply of oxygen blast; continuous removal of reaction products; dust removal suppression; phased condensation of sublimates; afterburning of CO; separation of metals by specific gravity; Utilization and transfer of heat to the steam generator. Calculations show that when working with technically pure oxygen (no NOx emissions, reduced gas volumes), safe working temperatures can reach 2000 ^° C. Factory manufacturing of the main equipment provides a life of up to 30 years.

In our opinion, one of the most promising among world developments is the one-stage process of liquid-phase recovery Romelt / V.A. Romenets, New processes of metal production: state and prospects, Metallypg JVa 11, 2001, K.Kh. Schubert, H.B. Lungren, P. Steffen, Level of development of direct reduction of iron ores and smelting and reduction processes, “Black metals”, January 1997 /, proposed and developed under experimental industrial conditions by Russian scientists and engineers at the Novolipetsk Metallurgical Plant (HJIMK).

The material balances of the Romelt process are significantly different from the domain, despite the similarity of both in the resulting product. The Romelt process is implemented in a rectangular shaped hearth furnace, internally clad with refractory materials. The process itself assumes the presence of redox conditions in the furnace (unit). In the liquid slag bath in the area of the tuyeres of the lower row, there is a zone of oxidation of carbon to CO and reduction of oxides to metal. Above the slag bath, there is only an oxidizing zone for afterburning the released gases in order to return heat to the bath. However, the mechanism for returning heat from the afterburning zone to the liquid bath has not been finalized. It leads to the need to find technological solutions for organizing the return of heat from the afterburning of exhaust gases, since the melting process in a liquid bath itself is essentially endothermic and dies out without supplying heat. In addition, the issue of heat recovery of waste gases having a temperature of up to 2000 ° C is very significant from the point of view of the cost-effectiveness of the melting process in a liquid bath. In classical metallurgy, heat-recovery boilers of various designs are used for this, which produce water or steam of technological parameters used directly on factory / RLJ 2118620, ClOJ 3/86, 1998 /. However, the use of recovery boilers does not solve the problem of heat return to the liquid bath, because they are intended for their purpose only to convert the heat of gases into the thermal energy of cooling water (steam).

The invention solves the problem of overcoming these drawbacks, namely, to create a device for smelting metals or alloys, in which heat could be returned to the endothermic liquid bath of the furnace without additional consumption of carbon-containing fuel and oxygen blast.

To solve this problem, a device for smelting metals or alloys is proposed, containing a cylindrical furnace with a hearth, equipped with a cooling system, overflows for the release of metal and slag, tuyeres for gas supply, a loading device and a heat recovery system. The cylindrical furnace is located in the furnace space of the boiler unit with liquid slag removal between the lower tier of the burners of the boiler unit and the lower collector of water-cooled screens.

In addition, it is proposed to equip the air supply system to the burners of the boiler unit with a heat exchanger associated with the furnace cooling system, for example, a liquid metal-air heat exchanger (sodium air)

In addition, it is proposed to include a liquid metal circuit, fully or partially located in the furnace wall, in the furnace cooling system.

Additionally, it is proposed to fill the liquid metal circuit with sodium.

In addition, it is proposed to insulate the walls of the sodium-cooled furnace from the steam generating tubes of the furnace of the boiler unit with a layer of acidic ferrous slag, for example, granulated slag of copper smelting.

In addition, it is proposed that one or more burners of the lower tier be used to direct the furnaces of the boiler unit into the interior of the furnace.

Implementation of a device for smelting metals or alloys containing a cylindrical furnace with a hearth, equipped with a cooling system, overflows for the release of metal and slag, tuyeres for supplying gas, a loading device and a heat recovery system, an arrangement of a cylindrical furnace in the furnace space of a boiler unit with liquid slag removal between the bottom tier burners of the boiler unit and the lower collector of water-cooled screens can reduce the consumption of oxygen, coal and slag while maintaining the performance of cast iron. In addition, the inventive device allows to obtain superheated water vapor energy parameters, which can be used to generate electricity with maximum efficiency. Thus, a technical result is achieved.

In FIG. 1 presents the inventive device, where 1 is a cylindrical furnace with a hearth, 2 is a cooling system made in the form of a liquid-metal sodium circuit, 3 is an overflow for metal production, 4 - an overflow for the production of slag, 5 - lances for gas supply, 6 - a loading device, 7 - a heat recovery system, 8 - a boiler unit, 9 - a furnace space of a boiler unit, 10 - a lower tier of burners of a boiler unit, 11 - water-cooled screens, 12 - lower collector of water-cooled screens, 13 - air supply system to the burners of the boiler unit, 14, 15 - burners of the boiler unit, 16 - sodium-air heat exchanger, 17 - electromagnetic pump, 18 - furnace insulation.

The device operates as follows. The boiler unit 8 is started up and brought to the rated operating parameters for the installed capacity (for pressure and temperature and the consumption of superheated steam, for air and fuel consumption) using standard technology with power generation. Simultaneously with the start-up of the boiler unit 8, after turning on the burners 14 and 15, the liquid metal sodium circuit 2 is turned on, pumping sodium by the electric pump 18 along the circuit furnace 1 - the sodium-air heat exchanger 16, heating the air in the air supply system to the burners of the boiler unit 13 with the heat of sodium. in the furnace 1, liquid slag resulting from the combustion of fuel (coal, fuel oil) in the boiler unit 8. Simultaneously with the accumulation of slag, the required amount of flux is fed into the furnace through the loading device 6 (lime silicate sand) to adjust its chemical composition in order to lower its melting temperature and prepare a slag bath for loading the charge (ore, coal, waste) and metal smelting.

After the accumulation of the slag bath in the furnace 1, tuyeres for supplying gas 5 are turned on and the ore or metal-containing wastes are continuously fed, for example, slag from steel production and slag from copper smelting, coal and fluxes through the loading device 6 into the furnace 1. In this case, due to the continuous operation of one or more burners of the lower tier 10, there is a continuous supply of additional thermal energy to the furnace 1, which compensates for the endothermy of the metal smelting process, thereby significantly reducing the amount of additional coal and oxygen. The flue gases emitted from the furnace (CO, H ₂ ), which did not have time to burn in the slag bath, enter the furnace space of the boiler unit 9, where they burn to CO ₂ and H ₂ O, giving the boiler unit its calorific value, thereby compensating for the heat consumption combustion of fuel in the lower burner 15 directed to the furnace 1.

The fuel combustion torch in the boiler unit 8 has a temperature of 2000-2200 ⁰ C (depending on the type of fuel burned), the temperature of the slag melt and metal in furnace 1 is 1400-1500 ⁰ C. Therefore, a certain part of the heat enters the liquid bath of the furnace by radiation from the torch in the furnace, however, the amount of this heat (due to the difference in these temperatures) is not more than 10% of the heat deficit in the furnace required to cover the furnace due to the endothermy of the metal smelting process. However, this is an additional source of heat return to the liquid bath of furnace 1 is important for maintaining the heat balance in the inventive device, as well as in that it gives the system thermal inertia in transient conditions, maintaining slag in the furnace in a liquid state.

The standard gas cleaning and dust collection systems of the boiler unit provide environmental requirements for discharges into the environment, so there is no need to create similar additional systems for the operation of the furnace.

During operation of the device, the accumulated liquid metal generated in the metallurgical process in the furnace 1 is discharged continuously from furnace 1 through flow 3 to a bucket or other tank for further metallurgical redistribution. The accumulated liquid slag from the tuyere space (from the quiet slag zone) through the overflow 4 enters the slag or ladle for subsequent bottling or granulation.

The described sequence of technological operations ensures the long operation of the claimed device and the achievement of the goal.

Types of boiler units (steam generators) TPPs are very diverse. The most suitable for placing the furnace in the furnace space is a boiler unit with liquid slag removal, with pinch / Kovalev A.P., Lelyaev N.S., Panasenko M. D. et al. Steam generators, M.-L., Energia, 1966, p. . 39 /. Boiler units use various types of fuels, including coal, fuel oil, gas. Most preferred is a boiler unit using coal or low-grade heating oil. Moreover, their inherent disadvantage (relatively high salinity) becomes a useful quality, because allows you to accumulate a liquid slag bath in the furnace directly from the liquid slag formed during the combustion of these fuels. In addition, the accumulation of liquid slag in the furnace, simultaneously with the additional introduction of fluxes (lime, silicate sand) into it to lower its melting temperature, can reduce the heat loss of the boiler unit with the physical heat of the slag, thereby increasing the thermal efficiency of the boiler unit. An additional input of fluxes allows you to adjust the chemical composition of the slag and obtain, using the furnace process, a useful product in the form of slag casting.

Typically, a boiler house liquid slag removal system The unit under pinch is equipped with one or more burners. The direction of one or more burners directly into the furnace will adjustably compensate for the endotherm of the furnace process of direct smelting of iron or iron. The thermal power of one burner is quite high, for example, with a typical fuel oil consumption in the burner of 0.5 kg / s (the calorific value of fuel oil is 35-45 MJ / kg, the diameter of the burner is DM 20), the thermal power of the burner is 18-23 MW, which is in excess enough to compensate for endothermia in the direct smelting of cast iron with a furnace capacity for metal of the order of 10 t / h. The authors calculated the oxygen consumption, row coal and slag output per ton of smelted iron from iron-containing raw materials using the MERA software package. According to the first option, smelting is performed without heating the bath with burners of the boiler unit. In the second embodiment, one of the 11 MW burners heats the bath with an efficiency of 50%. In the third option, two 20 MW burners heat the bath with an efficiency of 50%. The calculation results are summarized in a table.

Table

Для подогрева воздуха для горелок котельного агрегата в заявленном устройстве используют тепло, снимаемое натриевым теплоносителем с корпуса печи и передаваемое воздуху в теплообменнике натрий-воздух. Движение натрия в контуре 2 обеспечивается электромагнитным насосом 17. Вопрос безопасности использования натрия в котельном агрегате для охлаждения стенки печи решается следующим образом. Для предотвращения натриевого пожара при прободении стенки печи и исключения попадания высокотемпературного жидкого натрия на трубы котельного агрегата с вероятным, вследствие этого, повреждением труб и последующего взрывоопасного взаимодействия натрия с водой, кольцевое пространство между водоохлаждаемыми экранами топки и стенками печи заполнено изоляцией 18 из гранулированного шлака медеплавильного производства. Данный шлак имеет следующий состав: Fe+Fe₂0₃ (40-50%), SiO₂ (30-40%), CaO (5-15%), Al₂O₃ (5-8%), СuО+ZпО (1-3%). При протекании в него горячего (500-600⁰C) натрия, между натрием и шлаком протекает экзотермическая химическая реакция, продуктом которой является минералоподобный спёк, в котором натрий находится в виде твёрдых алюмосиликатов, и который содержит много элементарного железа, образовавшегося в результате восстановления натрием оксидов железа из шлака. Образование данного спёка в месте протечки натрия предотвращает её дальнейшее развитие и, более того, «плoмбиpyeт» место протечки. Таким образом, применение данного решения ликвидирует протечку натрия.

To heat the air for the burners of the boiler unit, the claimed device uses heat removed by the sodium coolant from the furnace body and transferred to the air in the sodium-air heat exchanger. The movement of sodium in circuit 2 is provided by an electromagnetic pump 17. The issue of the safety of the use of sodium in a boiler unit for cooling the furnace wall is solved as follows. To prevent a sodium fire during perforation of the furnace wall and to prevent high-temperature liquid sodium from entering the boiler unit pipes with possible pipe damage and subsequent explosive interaction of sodium with water, the annular space between the water-cooled furnace screens and the furnace walls is filled with insulation 18 from granulated copper smelting slag production. This slag has the following composition: Fe + Fe ₂ 0 ₃ (40-50%), SiO ₂ (30-40%), CaO (5-15%), Al ₂ O ₃ (5-8%), CuO + ZnO (1-3%). When hot (500-600 ⁰ C) sodium flows into it, an exothermic chemical reaction takes place between sodium and slag, the product of which is a mineral-like cake, in which sodium is in the form of solid aluminosilicates, and which contains a lot of elemental iron formed as a result of sodium reduction iron oxides from slag. The formation of this sinter at the site of sodium leakage prevents its further development and, moreover, “seals” the leakage site. Thus, the use of this solution eliminates the leakage of sodium.

In general, the use of a boiler unit in a standard configuration of a thermal power plant (boiler, turbine, electric generator, steam-water circuit with equipment, gas purification of flue gases and other equipment) for the operation of the furnace allows solving the problem of long-term and stable operation of the process of direct smelting of iron or iron, slag from ore and / or metal waste.

Claims

Claim 1. A device for smelting metals or alloys containing a cylindrical furnace with a hearth, equipped with a cooling system, overflows for the release of metal and slag, tuyeres for supplying gas, a loading device and a heat recovery system, while the cylindrical furnace is located in the furnace space of the boiler unit with liquid slag removal between the lower tier of the burners of the boiler unit and the lower collector of water-cooled screens. 2. The device according to p. 1, characterized in that the air supply system to the burners of the boiler unit is equipped with a heat exchanger associated with the furnace cooling system. 3. The device according to claim 2, characterized in that the air supply system to the burners of the boiler unit is equipped with a liquid metal-air heat exchanger. 4. The device according to claim 3, characterized in that the air supply system to the burners of the boiler unit is equipped with a sodium-air heat exchanger. 5. The device according to p. 1 characterized in that the cooling system of the furnace is made in the form of a liquid metal circuit, fully or partially located in the wall of the furnace. 6. The device according to p. 5 characterized in that the liquid metal circuit is filled with sodium. 7. The device according to p. 6, characterized in that the walls The sodium-cooled furnaces are isolated from the steam generating tubes of the furnace of the boiler unit with a layer of acidic ferrous slag. 8. The device according to p. 7, characterized in that the walls of the sodium-cooled furnace are isolated from the steam generating tubes of the furnace of the boiler unit by a layer of granulated slag from copper smelting. 9. The device according to claim 1, characterized in that one or more burners of the lower tier of the furnace of the boiler unit is directed into the interior of the furnace.