CN1036247A - Combined method for producing energy and iron and steel materials - Google Patents

Abstract

The invention provides a method and device for efficiently producing electric energy from coal equipment, and at the same time provide a method useful in the production of iron or steel and in the extraction of coal A less expensive procedure when using substances such as oils. In the first stage, coal's The liquefaction/pyrolysis process is used to remove volatiles and form very low Volatile broken char. The crushed coke of coal is best made into pellets, which can be And used as a reducing agent in the second stage of smelting. reduction and melting of iron The smelting operation is best carried out in a pressurized cupola, and the heat generated by the high pressure The output gas is used directly and/or indirectly for electricity production in the third stage, and Generates steam used to propel certain sections in the first and second stages.

Description

The present invention relates to thermoelectric energy production. In particular the invention relates to the production of energy from coal. An integrated approach involves removing useful oils and the like from the coal fuel by treating it in a liquefaction process or step. The resulting low volatility ground coke is then used in iron reduction and smelting processes. Gas products are produced during the refining of iron at high temperatures. These gases are used directly and/or indirectly to power turbines to produce electrical energy. In particular the whole process relates to a system which has the advantage of exploiting the properties of the individual steps or stages in order to facilitate a relatively energy efficient process as a whole. In a preferred application, steel is produced from the products of iron reduction and smelting processes.

In an advantageous configuration, the iron is reduced at superatmospheric pressure, under which the gas produced can be more efficiently used to power the turbine and generate electrical energy. This invention addresses the problems associated with handling molten metals under pressure.

In the last decade, efficient and cheaper production of electrical energy has become a more important issue. Of the various types of power plants, coal-fired power plants have become particularly popular and widely used. Reasons for this include better adaptability to various sites and wider availability of cheaper fuels.

Problems in conventional coal combustion systems relate to the general methodology of fuel utilization. In a typical system the coal is simply burned and the waste is thrown away. This leads to two practical problems. First, coal fuels often contain relatively useful organic components that can be separated and refined into useful oil products such as diesel fuel or the like. Typically, these components are simply burned as an inexpensive fuel along with coal residues in common plants. Clearly, this is a poor use of coal as a natural resource.

Second, typical systems typically require higher grade fuel coal. For example, coal, which contains a considerable amount of sodium in it, is not readily available because it does not burn completely. If the above-mentioned substances in coal are first separated therefrom, low-rank coal can be effectively utilized as a fuel source.

Coal liquefaction, that is, the removal of volatile substances from coal, is well known. However, the above-mentioned methods are generally not practical for coal used as fuel to generate electricity. A more important reason for this is that the resulting coke of coal is not a desirable fuel. Although the above-mentioned crushed coke has sufficient energy content, it usually does not burn completely cleanly in normal boilers. Therefore, the application of this broken coke has been restricted by power companies.

Coal is also used in the steelmaking industry, generally in the form of metallurgical coke, for example for the reduction of metals, such as iron oxides. In one known method, the coal product is agglomerated with water, silica, burnt limestone and taconite and processed in a high temperature furnace such as a cupola. This method of producing metallic iron has thus far received little attention.

There has been a need for a more efficient method of producing energy utilizing coal and coal products as a primary fuel source. In more detail, there has been a need for a method of energy production in which the value of coal fuel is utilized more efficiently and practically, as opposed to its simple natural fuel value. For example, it is used in iron refining and boiler operation. A particularly useful method may be one in which steel is produced as a by-product of energy production.

If the iron is reduced at superatmospheric pressure, the efficiency is increased because the output gas has a higher energy that can be extracted for power generation. The thermal efficiency is also improved, and a high gas concentration and a faster reaction rate are obtained, thus resulting in a more complete reduction. High-pressure cupolas require smaller vessels for output gas purification, allowing for off-Sight installations and lower costs. The application of pressure reduction has been avoided in the past due to special handling problems presented by molten metals under pressure.

It is therefore an object of the present invention to: provide a method for producing electrical energy from coal fuel, wherein the oil component is removed from the coal before it is used as fuel; Coke products are used in iron oxide reduction and smelting processes; providing a method wherein high pressure hot gaseous products are formed during iron refining which can be used to produce electrical power when the gas is passed through a turbine apparatus; providing a method wherein turbine The equipment preferably comprises (in order) a gas turbine driven by gases from the iron refining process, and a steam powered generator driven by steam produced in a boiler heated by the hot exhaust gases from the gas turbine; A method is provided in which steam generated from a boiler heated by hot exhaust gas generated from crushed coke of coal used in iron refining processes is used partly as a heat source for coal liquefaction. to initially produce ground coke material; to provide an integrated process for the production of oil products, reduction of iron oxides, and production of electrical power utilizing coal as an initial source of fuel and a source of reducing agent; and to provide a process, This method is energy efficient and relatively easy to implement, and is particularly well suited for its proposed application. A further object of the invention is to provide an integrated method which includes a step in the production of steel from the products of the smelting process. According to an advantageous arrangement, the further object of the present invention is to provide a method for reducing iron at a pressure above atmospheric pressure, so that the hot output gas produced under pressure can be used in a further step in the production of electrical energy. The output gas under pressure has a higher energy, thereby achieving energy production more efficiently; and providing a method in which the molten metal under pressure is pressed upwards against a vertical discharge by its own pressure, thereby utilizing the metal's The weight counteracts the pressure and causes the metal to be expelled at a height where its pressure is close to atmospheric pressure. Advantages of other tasks of the present invention emerge from the following description and with reference to the associated drawings, which are presented in accordance with the methods explained and examples of various implementations and applications of the invention.

The present invention relates to an integrated process and plant designed for utilizing coal in an efficient process, producing energy and enabling low cost iron refining. In addition, valuable oil products can be extracted from fuel sources for use in various industries, including the fuel industry, such as the diesel fuel industry. The integrated method can be broken down into a number of individual steps and stages; however, as will be understood from the detailed description, some advantages come from organizing the stages into an efficient interdependent system in which the energy from the different stages is harnessed in a more efficient manner. Utilize to help drive other steps and stages. This is readily apparent from the diagrams described in detail below. The result is to provide an integrated utilization plant that produces oil, refines iron and produces energy at a relatively low cost. In one particular plant, the product from the iron refining step is used in the steelmaking process.

Refining iron at pressures above 50 psig will understandably have the added benefit of producing export gases under pressure. These pressurized gases are desirable because they have more energy than gases at atmospheric pressure and therefore generate more energy when driving the turbine. The problems associated with controlling pressurized molten metal during pressurized refining are not limited by the type of equipment employed. In one advantageous arrangement, the pressure of the gas pushes the metal up the vertical discharge. The weight of the metal counteracts the pressure of the gas so that at some altitude the top pressure of the molten metal is reduced to near atmospheric pressure, thus solving the operational problem. The molten metal can then be safely drained and easily handled.

In the first stage of the invention, coal supplied as a fuel source is treated in a liquefaction step to remove volatile components therefrom. At the same time, unwanted inorganic useful components are also extracted. With regard to the latter, it is an advantage that these inorganic useful components are easily removed in the process which might otherwise prevent the desired utilization of coal as a fuel source. Therefore, lower quality coals can be used in the process of the present invention. The result is improved cost economy and efficiency.

In the liquefaction step, various liquefaction methods can be used. One approach is to follow solvent extraction with pyrolysis. Typically, a phenolic solvent is best used for the extraction procedure. This process is followed by relatively mild pyrolysis using steam and oxygen to drive off volatiles and remove useful liquid components and produce a low volatility ground coke product for use in iron The restore process, which is the next level.

Alternatives to the dedicated liquefaction process described above include: hydrothermal treatment followed by water/steam extraction (instead of organic solvent extraction), and mild pyrolysis; steam extraction only and pyrolysis only. A combination of organic solvent extraction and mild pyrolysis is often chosen for its energy efficiency and ability to achieve removal of substantially all volatile components, resulting in particularly desirable broken coke suitable for reduction purposes.

The ground coke resulting from the liquefaction step is usually quite reactive and generally powdery. If the material is dry, it will ignite spontaneously when exposed to air. Therefore, if it is to be stored for a significant period of time, it is usually best to place it in an inert atmosphere and/or slightly moisten it, generally about 30% moisture (by weight) is sufficient to inhibit combustion.

The active quality of this crushed char material makes it an excellent substitute for many activated carbon applications, such as in water purification. The high cost of activated carbon makes this coke crushed material an economical source. The use of this coke crushed material in the purification step has little effect on its effectiveness in the subsequent iron reduction process since there is no loss of energy.

Following any application as activated carbon, this crushed char material will be prepared for iron reduction and smelting steps. In one embodiment, this is preferably accomplished by a pelletizing process in which the crushed coke material is mixed with a binder, typically including lime and silica, and steam consolidated, ie hardened into pellets. The shape of the pellets generally enhances the iron reduction chemistry and makes this coke crushed material easy to handle and less likely to be blown by gases in the iron reduction step.

The crushed coke material formed in the first stage described above can be used for reduction and smelting of various iron materials, including iron ores such as taconite, and metal scrap. If metal scrap is used, the pellets manufactured as described above are generally mixed with the metal scrap and subjected to a refining process. The cost of the method is still very low if the use of scrap iron is reduced, since smelting in the furnace installations used in this solution is less costly than smelting in standard furnaces. If an iron hearthstone such as taconite is used, then preferably some of this crushed char material is pelleted with the taconite itself, additionally the pellets also contain a binder.

In the second stage, typically in a furnace apparatus such as a furnace or cupola, iron oxides are reduced in the presence of crushed coke material as reducing agent. Typical second-stage products generally include slag, liquid metal and hot gases. This hot gas is used directly and/or indirectly in a third, usual stage to produce electrical energy. In some particular installations, the conditions of the second stage may be slightly altered to advantage. For example, chromite can be included in pellets to produce stainless iron. Direct reduced iron can also be formed using kiln conditions. In an advantageous auxiliary treatment step of the second stage, the reduced iron oxide material can be refined into steel, for example by operating a kiln or an add-on to a kiln and by injecting gases and minerals.

Since the output gas is produced under pressure, it is advantageous to operate the reduction of the second stage under pressure. Using pressurized gas to drive the turbines results in more efficient third-level power production. In an advantageous embodiment of the invention, the problems associated with pressurized molten metal production under pressure are solved by means of a vertical discharge for depressurization. The pressure of the gas forces the metal up the discharge; as the metal rises, its own weight counteracts the pressure of the gas so that at some altitude the top pressure drops to atmospheric pressure and the molten metal can be discharged for further manipulation.

In one embodiment instead of the second stage, the coke crushed material of the coal is mixed with lime and gasified. This gas is then brought into contact with ferrous materials to be reduced and smelted. In a preferred system, broken coke of coal is gasified in one chamber, for example in a conventional melter/gasifier. Iron material such as ore is first fed into a separate chamber where it is exposed to hot gas from the melter/gasifier. The reduced ore materials are then sent directly to the melter/gasifier where they are smelted and discharged as pig iron. This pig iron can be refined into steel as mentioned above.

The third stage involves utilizing hot gas streams from cupolas or reduction and smelting processes. In some specific installations, cupolas operating under high pressure can also be configured to increase efficiency and reduce residence time. In other cases, lower pressure processes may be used. In both cases, the hot gases exiting the reduction and smelting processes typically contain about 30-40% carbon monoxide along with other gases. The rapidly cooled gas can have a lower temperature of 300-600°F compared to the operating temperature of the cupola, which generally exceeds 2000°F (typically about 2500-2900°F). Often contains particulate matter such as burnt dust. For a typical process, the exhaust gas passes through a filter or similar device to remove solid particles.

In the preferred third stage process, the exhaust gas is directed to a combustor where it is combusted in the presence of oxygen to oxidize carbon monoxide and raise the temperature of the gas substantially, typically in excess of 2000°F. This very hot gas, which has considerable energy, is then pressed into a gas turbine plant where the energy of the gas is used directly to produce electricity. It is very desirable if the gases come from a device in the cupola which is advantageously pressurized and thus under considerable pressure. High pressure gas turbines are efficient devices for extracting energy provided by the output gas pressure. The cooler, lower energy gas supplied by the gas turbine unit is then preferably introduced into a boiler to generate steam. The steam produced by the boiler can be used to drive a steam turbine to produce electricity. Additionally, the hot steam produced by the boiler can be used to facilitate a number of steps, for example as a first stage solvent and/or heat source for steam extraction/liquefaction.

When the hot gases leave the boiler they still contain a considerable amount of heat which can be effectively used to facilitate the process of the present invention. For example, these hot gases can be pushed through a heat exchanger to heat the air introduced into various steps of the process, including the hot blast cupola introduced into the second stage, or any other device in the second stage. Air.

In the schematic diagrams detailed below, a particularly efficient system utilizing the steam generated by the boiler and utilizing the heat generated in the smelting stage is shown. These drawings constitute a part of this specification and include an exemplary embodiment structure of the present invention, and illustrate the tasks and features of the present invention. It is to be understood that the schematic drawings illustrate only generally specific devices and that many specific devices may be used in accordance with the principles of the invention.

Fig. 1 is a schematic diagram of an equipment system for implementing the method of the present invention.

Fig. 2 is a partial schematic diagram of an equipment system according to an alternative specific implementation structure of the present invention.

Fig. 3 is a partial schematic diagram of an equipment system according to a specific implementation structure of the present invention. The molten metal discharged from the cupola is refined into steel.

Figure 4 is a partial schematic diagram of a plant system according to an alternative embodiment in which molten material discharged from a cupola furnace is refined into steel.

Fig. 5 is a schematic transverse cross-sectional view along the line of Fig. 45-5.

Fig. 6 is a schematic diagram of a specific apparatus for iron reduction process under high pressure according to the present invention.

Figure 7 is a cross-sectional view of the bottom of a high pressure cupola of an advantageous arrangement taken along line 7-7 of Figure 6, in accordance with the present invention.

Figure 8 is a cross-sectional view of the vertical discharge device taken along line 8-8 of Figure 6, in accordance with the present invention.

The specific implementation structure of the present invention is described in detail here as required. However, it should be understood that the specific implementation structures disclosed are merely exemplary of the invention, which may be embodied in various forms. Specific structural and functional details described herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis enabling one skilled in the art to employ the present invention in virtually any suitably detailed system. .

The process of the present invention is generally described in terms of three stages of entry: in the first stage the coal is processed into ground coke and the oil content is removed; in the second stage the ground coke product is used in an iron refining operation to produce useful the high-pressure hot gases from the second stage and reduce the iron that can be refined into steel; and in the third stage, the high-pressure hot gases from the second stage are used to produce electricity. In a preferred plant as described and shown, the three stages cooperate so that the energy generated in each stage is used efficiently and optimally for the overall process. This is evident from the detailed description below.

Stage 1 - Coal to Form Crushed Coke and Coal Tar Products

Referring to Figure 1, reference numeral 1 generally designates the first stage of the process in which coal is processed into coke and oily substances are extracted therefrom. Figure 1 may be understood as an embodiment of a power plant operating in accordance with the principles of the present invention. The supplied coal is denoted by reference numeral 5 . Various grades of coal may be used in the process of the present invention, including in some cases those grades which contain too high a mineral content to normally be effective as conventional boiler feedstock.

In the first stage, an extraction/liquefaction step is used to remove material from the coal feedstock feed. A variety of methods are used in the methods of the present invention. It is generally desirable to remove primarily volatile constituents and also extract inorganic constituents from the coal to leave a coke-crushed material with a lower volatile matter content.

In a preferred application of the invention, the coal feed 5 is sent to a liquefaction system comprising an autoclave 6 where the coal is extracted with a solvent, for example a phenolic solvent or water/steam. Extraction with a phenolic solvent is generally effective at rapidly extracting volatiles from coal at a temperature of about 350-420°C and a pressure of 450 psig. Said hot solvent is fed into the autoclave through line 7 and discharged from the autoclave through line 8 . The solvent shown in FIG. 1 is at least partially heated by heat exchangers 10 and 11 which are described in further detail below. A heat exchanger 15 is provided to cool the solvent from the extraction step. The solvent also passes through the cooler 16 into a separator 17 where the extracted oily substance is separated from the solvent. Separator 17 may be of any of a variety of common types, including distillation systems, the oily product being sent away in line 18 and the solvent flowing out in line 19 and reintroduced in line 7 into autoclave 6 . The solvent shown for this embodiment is led through line 19 through heat exchanger 15 and heat exchangers 10 and 11 so that the solvent is sufficiently heated to be extracted by a continuous process. The volatiles removed through line 18 are divided into two parts along lines 20 and 21 as shown. More useful coal tar, such as oils used as diesel fuel or for similar purposes, is usually separated in line 20 using conventional separation techniques not detailed, while the less useful but flammable material is introduced through line 21 as a supplementary fuel source in one of the boilers of the third stage described below. Typically at least about 65 gallons of useful oil can be extracted from one ton of coal.

In the second step of a preferred first-stage liquefaction system, part of the extraction residue from the autoclave 6 is introduced into a pyrolysis furnace or combustion chamber 30 where it is subjected to mild pyrolysis to ensure that the volatile species are as low as possible. until it decreases. The reason for this is the requirement to use crushed coke with little volatile matter in the second iron reduction step. Pyrolysis, typically carried out at about 600°C and one atmosphere in the presence of steam and oxygen, tends to draw residual volatiles down the pipes, leaving powdery coke deposits. This relatively mild pyrolysis is advantageous because it consumes less energy, which energy consumption can be at least partially met by the heat supplied by the heat exchanger 10 . Volatile materials expelled through line 31 may be collected as desired by conventional means. If necessary or desired, a steam recirculation system provided for continuous feed through line 32 from heat exchanger 10 may be provided in conventional manner.

It should be understood that, for example, extraction and pyrolysis as described can be used to remove metal salts and organic volatile substances in crushed coke. Shredded coke material exits the pyrolysis furnace 30 through conduit 35 as shown. Furthermore, this crushed coke material has a low volatile matter content and is therefore well suited for use in the second stage as described below.

Various alternative liquefaction procedures can be utilized, including secondary liquefaction with hot water pretreatment and water/steam extraction instead of organic solvents. Usually such a system requires a subsequent low temperature pyrolysis. Hot water pretreatment of the coal feed facilitates extraction by steam methods. Such methods typically include, for example, a short, typically 15-25 minute, pretreatment with water at about 200°C, followed by steam extraction at about 375°C and about 750 psig. This subsequent pyrolysis is carried out in the furnace 30, for example at about 600°C and atmospheric pressure, as described above.

Although typical single-step liquefaction systems may be inefficient because they do not readily produce fine coke with very low volatile matter content, single-step liquefaction methods may also be suitable for use in connection with the present invention; or when the above-mentioned system When run, only a small amount of useful liquid product is produced. In one type of single-step system, only the pyrolysis process takes place. And cancel the extraction process in the autoclave 6. In another type of single-step system, the extraction process is done only in the autoclave 6 and the pyrolysis process in 30 is eliminated. Of course, the selected liquefaction method generally depends on the cost, the nature of the coal material and the desired coke crushed product.

This active crushed coke material is suitable for use as activated carbon, for example for water purification. This crushed coke material can be used for metal reduction after purification. Since the energy of this broken coke is not significantly affected, its use in purification will not significantly reduce the reducing effect of this broken coke material. Activated carbon or charcoal is very expensive. Crushed coke provides a cheap source of the above-mentioned active materials, and can also be used as a deactivated broken coke product in the subsequent steelmaking production.

Regardless of the choice of liquefaction method, this integrated approach is designed to provide low volatility ground coke material for introduction into the second stage. Furthermore, this method is preferred to achieve the production of crushed coke at the lowest possible cost and with the highest energy efficiency. It is readily appreciated that the solvent extraction/mild pyrolysis step detailed above is often advantageous because extreme conditions and long reaction times are avoided.

Second stage - reduction of iron; refining into steel

According to the second stage of the method of the present invention, the iron material is reduced and/or smelted into iron for steelmaking or the like. This reduced and/or smelted iron material can come from a variety of sources, including iron ore and scrap iron. In general, in accordance with the present invention, the use of more expensive coke material is avoided and replaced by broken coke, a by-product of less expensive energy production, in the manufacture of less expensive iron and steel products. This is accomplished as described below.

Typically the ground coke from output conduit 35 is powdery and tends to be highly reactive. Dry coke may or is likely to ignite spontaneously if exposed to oxygen. Generally, rather than being stored as a powder, the coke crushed material is preferably pelletized for use in the iron reduction reaction, if necessary.

The properties of the pellets produced depend in part on the properties of the iron being reduced and/or smelted. In general, various sources of iron can be used in the methods of the invention. Most typically, several primary sources are available: oxides, for example in the form of iron ores such as taconite; scrap metallic iron; and waste oxides, such as waste iron oxides produced during the production and fabrication of steel thing. It can be understood that scrap iron generally contains a large amount of iron oxides.

In Figure 1, one method of using taconite is illustrated. The coke crushed material is ground in a mill 40 and introduced via line 41 to a mixing and pelletizing system 42 where it is pelletized with various binding materials and, if necessary, iron ore. Various conventional particle formers, such as mixing mills and pelletizing pans, may be used as part of system 42 . It is generally required that the crushed coke material be mixed with the ore shown introduced through line 45 in such a way as to ensure pellet formation. To achieve pellet formation, small amounts of binding materials such as water, silica and burnt limestone are added to the pellets. As shown in Figure 1, water, silica and limestone are fed through lines 46, 47 and 48, respectively. These materials improve consolidation under conditions of heated use.

A typical agglomeration process involves forming many small pellets, about 1/4-1-1/2 inch in diameter, although variations are available, each containing (by weight) about 10-18% broken char, about 60-80% Taconite, about 8-15% water and about 1-8% burnt lime. Such particles are generally readily consolidated and provide sufficient incorporation of carbon (coke) and iron to facilitate the reduction process when the particles are heated.

Heat and steam are generally used to promote consolidation. Referring to Figure 1, pellets 50 formed by pellet maker 42 are introduced through line 51 into autoclave 52 for consolidation as shown. In the autoclave 52, heat and steam are applied to provide a stable and firm pellet material. Typically steam at about 175-225°C and 75-300 psig is effective for making such hard particles. However, it will be appreciated that various pressure and temperature conditions may be used, depending upon the composition of the particular pellets involved, and the intended use of the pellets. Additionally, temperature and pressure optimization can be achieved based on various system tests to increase energy savings and achieve desired hardening times.

Pellets, such as those described above, may be introduced into an iron-reducing furnace such as a cupola. In some cases, however, it is preferable to use scrap iron rather than taconite or iron ore. In the above cases, the pellets of crushed coke material should generally be formed without direct mixing of iron, but rather only with pellets of crushed coke material containing sufficient silica, limestone and/or water to provide an effective Consolidation. For the latter modification of this method, the crushed coke pellets are usually charged to the cupola in admixture with scrap iron.

Referring to FIG. 1 , since hardening in autoclave 52 is a relatively low temperature process, hardening can be achieved at least in part using steam supplied by line 55 and heated by heat exchanger 56 . As shown, the preferred heat exchanger 56 is at least partially heated by steam lines 57 and 58 from the boiler of the third stage. This is detailed below. This advantage results in lower energy consumption for the entire process.

As shown in FIG. 1 , pellets from autoclave 52 are introduced into cupola 60 through conduit 61 . Various conventional cupolas 60 can be used in the method of the present invention. Cupola structure producing iron and slag at the 1983 Lignite Symposium by William B. Hauserman and Warrack G. Willson, Grand Forks, North Dakota, May 18-19, 1983 It is generally described in the submission "Conclusions on Slagging, Fixed-Bed Gasification of Lignite", which is hereby incorporated by reference. Additionally, it is envisioned that, in certain applications, modified cupola furnaces operating at higher pressures, such as 100-300 psig, may be used to facilitate the reduction process. In the above applications, energy production is enhanced through the use of pressurized cupolas that generate energy. The output gas is pressurized as described to have higher energy and promote more efficient energy production. As an example, it is described below. Other furnace systems, such as kilns, may be used in some processes.

Typically the charge for the cupola 60 is fed in solid lumps. To allow air or the like to pass through the charge. In the case of reduced taconite, generally the iron ore-containing pellets are fed singly into the cupola or furnace. Usually half of the coke crushed material is not in the form of pellets but consolidated with iron. Conversely, if scrap metal iron is included, the coke pellets are mixed with the scrap metal in a heap in the furnace. Hot air to facilitate the reduction process is introduced into the cupola 60 through 67 as shown. Gases and minerals may be injected through duct 67a into the cupola for refining steel. The slag and molten metal are removed through conduit 68 as shown. It will be readily understood that this method involves a relatively cost-effective and energy-efficient step in the manufacture of steel products or the like. In addition, since the high efficiency allows the use of smaller smelting furnaces or cupolas, only lower investment costs are involved. Capital costs are also reduced through the extraction of useful oil in the first stage and the more efficient production of energy in the third stage.

Hot gases generated by cupola 60 are exhausted along conduit 75 as shown. For typical cupola operation, these hot gases contain approximately 30-40% carbon monoxide and are approximately 300-600°F, while in some systems using pressurized cupolas these hot gases can be at 250- at a pressure of 300 psi (absolute). In a typical cupola operation, gas is bubbled into the cupola 60, preferably at about 800-1200°F, where the gas is then heated to 2500-2900°F. Because the gases transfer thermal energy to the materials in the cupola 60, they are usually cooled very rapidly. In certain advantageous systems of the present invention, as noted above, the cupola can be operated at relatively high pressures, about 250-300 psig, to efficiently produce energy. This point will be described below. In other cases, near atmospheric pressure may be used.

The gas drawn off via line 75 is used in a preferred manner in a third stage (reference number 76 ) for the production of electrical energy.

Level 3 - Electric Energy Production

In the third stage, as described above, the hot gases exhausted from the cupola 60 are used to produce electrical energy. Additionally, as noted above, the thermal energy of these gases is used to facilitate other stages of the process. In an advantageous configuration, the hot gases from the cupola 60 are still under pressure and can be further used to produce electrical energy in some of the ways described above. Referring to Figure 1, hot gases from cupola 60 are preferably directed through conduit 75 through a filter or dust collector 80 to remove entrained particulate matter from the cupola process. These include, for example, products from the treatment of crushed coke pellets with hot gases. Typically, this screen or filter assembly is used to prevent damage to downstream equipment. Sulfur can also be effectively removed here with absorbents, for example in gas filters.

As noted above, the gas in line 75 contains a substantial amount of carbon monoxide (typically 30-40%). These carbon monoxides can be utilized. In particular, this carbon monoxide is oxidized by air in the burner 81 . This raises the temperature of the gas to approximately 1800-2200°F and further results in the removal of potentially dangerous carbon monoxide. Air for oxidation is supplied to burner 81 via conduit 82 as shown. The hot oxidized gas flows out along conduit 83 as shown.

The high temperature and high pressure gas from the burner 81 is used to generate electricity. It will be readily understood that due to the high efficiency at which the turbine operates, there is the advantage of utilizing the relatively high pressure gas from the cupola 60 . These gases have high energy under pressure, which can be tapped to drive high-pressure gas turbines, thus enabling more efficient electricity production. For the preferred plant system, the gas turbine 85 is powered by cupola gas for electrical production.

After passing through gas turbine 85, the hot gas indicated by conduit 86 is also a relatively high energy source in the preferred process due to its relatively high temperature, typically about 800-1100°F. These exhaust gases and shown are introduced into a boiler 90 for generating steam. This steam can be utilized in various ways. For example, steam passing through the illustrated conduit 91 is used to drive a turbine 92 for the production of additional electrical power. The steam exiting the turbine 92 provides heat along line 95 as shown to heat the heat exchanger 11 used to drive the initial extraction in the first stage. The discharge conduit 95 shown is also connected to the heat exchanger 56 via conduits 57 and 58, providing the energy source for the hardening of the pellets in the second stage. Finally, the steam or water is returned to boiler 90 via line 96 . NOTE: Turbine 85 may be used to drive a compressor, such as the one that supplies pressurized combustion air to cupola 60 or duct 82 .

Very hot steam at about 400°C or higher exits boiler 90 through line 105 as shown. These vapors are introduced into heat exchanger 10 via line 105 to facilitate the initial extraction process and also to facilitate the pyrolysis process. Once cooled, the steam/water is returned to the boiler via line 106 .

The heat input to boiler 90 can come from a variety of systems. For the preferred system of the present invention, most of the thermal power is provided by hot gases in conduit 86 exiting the cupola. Other sources of heat include energy derived from less important and less useful coal tar products, introduced into boiler 90 via line 21 as shown.

Hot gases exhausted from boiler 90 are exhausted along conduit 110 as shown. This gas also contains more heat and can be used in heat exchanger 111 for various purposes. The purpose of this heat exchanger includes heating the air entering the boiler 90 through line 112 and also helping to heat the air entering the cupola 60 through line 67 . Finally, gas from line 110 is vented to atmosphere along line 113 as shown. Typically the gases are first passed through a not shown scrubber unit or the like, which can be of conventional construction and is used for pollution control. Although these gases contain considerable amounts of carbon dioxide, the total emissions may be lower than conventional systems, where coal is less efficiently utilized.

From the foregoing, it will be readily appreciated that an advantage of the present invention is to provide an overall interdependent system in which coal is used very efficiently in a combined plant for the production of electricity and for the refining of iron. The more valuable component of coal, coal tar, is extracted first. The above-mentioned low-price crushed coke materials are not only used to reduce iron, but also reduce the cost of iron and steel products, and generate gaseous products that promote high-efficiency production of electric power.

Alternative second-level operations

In an alternative second stage operation, the dough making process is eliminated. Referring to FIG. 2 , coke crushed material from the first stage coal is fed through line 201 into a pressurized feed tank 200 where it is mixed with lime fed through line 202 . This mixture is fed through line 206 to a conventional melter/gasifier 205 under pressure. In the melter/gasifier 205, sufficient heat is provided to gasify the broken coke material of the coal. The released gas is fed through a pipe 201 into a reduction furnace containing an iron oxide material such as ore fed through a pipe 211 . The gas released from the reduction process is exhausted through line 212 and utilized in a manner similar to the gas exhausted from the cupola described above. For a typical system, the reduced iron feed passes through line 215 directly to the melter/gasifier where it is melted and discharged through line 216.

Modified method of producing steel

The process carried out in or in combination with cupola furnaces can be used to produce steel products as opposed to iron alone. As noted above, 67a in Figure 1 generally represents the ducts for the selective introduction of various gases and minerals into the steel-producing cupola. Two preferred modes and systems for carrying out steel production in the method according to the invention are readily understood by reference to FIGS. 3 , 4 and 5 . These figures schematically depict a multi-chamber refining unit that can be used in combination with a cupola to provide optimal refining.

Referring to Figure 3, there is shown a cupola 360 specially adapted for the production of steel. For the particular apparatus shown in FIG. 3 , the pellets are typically fed into the cupola 360 via conduit 361 , while exhaust gas escapes via conduit 362 . Air or oxygen is typically introduced into cupola 360 via conduit 363 . During operation, reduced iron 366 is concentrated at the bottom or region 365 of the cupola 360 . It is foreseeable that at the operating pressure of the cupola, the iron 366 may optionally flow into a multi-chamber refining unit or apparatus having an upper (first) chamber 368 and a lower (first) chamber 368 separated by an interface 370. b) Room 369. The upper chamber 368 communicates with the cupola 360 via a pipe 371 .

During a typical period of operation, iron is discharged from the cupola having a composition denoted "Cupola discharge" approximately as shown in Table 1 below. The aforementioned metals contain undesired amounts of carbon, sulfur, phosphorus, oxygen and other elements. The metal can be discharged under pressure, ie at the operating pressure of the cupola 360, through 375, the ingate means, and into the upper chamber 368. Gate 375 may include conventional means (not shown) for selectively opening and closing.

Typically, chambers 368 and 369 include means for selectively introducing gases and minerals therein. In the upper chamber, calcium oxide (lime) can be added to remove sulfur and phosphorus by forming slag. These materials should pass through conduit 376 into chamber 368 below the upper surface 377 of the melt. Conduit 376 is typically used to transport argon, nitrogen or other gas streams, typically at a rate of about 50 kilograms per ton of steel. Oxygen is also generally bubbled into the chamber, preferably also below the surface of the molten metal. The oxygen reacts with the carbon present to form carbon monoxide, which is discharged as a gas through line 371 into the cupola 360 . It can be predicted that for normal operation the composition of the molten metal leaving the upper chamber will generally be that shown in Table 1 under the column labeled "Upper Chamber Discharge". The slag 378 formed on the steel surface in the upper chamber 368 should be removed by means, for example selectively through the gate 382 through the pipe 381 .

Steel 383 may be selectively drained into lower chamber 369 using a gate or gating arrangement located at the bottom of upper chamber 368 . After gate 385 is reclosed, the pressure in lower chamber 369 can be reduced to atmospheric pressure as the chamber is vented through line 390 . The hot exhaust gas via conduit 390 can be directed elsewhere in the overall process, such as in a steam generating furnace.

The pressure in the lower chamber 369 facilitates the release of gas from the liquid steel. Aluminum may also be sprayed into lower chamber 369 through conduit 395, preferably with vigorous agitation. In a typical process, aluminum is injected at a rate of approximately 20-60 kg per ton of steel. Aluminum can react with oxygen to form alumina, which will bind to the slag. Usually, argon can also be input through the pipeline 395 to bubble the molten steel 396 and remove nitrogen and hydrogen. Generally, the injection rate of argon is close to 50 liters per minute per ton of steel. An added benefit of bubbling argon through the molten steel is the ability to carry inclusions to the surface where they bond with the slag. Generally, the above-mentioned inclusions include oxides, sulfides, sulfur oxides, nitrides and carbides of aluminum, iron, silicon and other elements. In the slag 397, a substantial portion of these substances include FeO, MnO and SiO. These materials are readily removed as slag through means such as line 398. Finished steel product is discharged through the bottom 399 .

After the aluminum, argon sparging process, the approximate composition of the liquid steel is shown in Table 1 below under the column labeled "Sprayed Aluminum and Argon".

After sparging aluminum and argon, the lower chamber is typically operated under partial vacuum to remove additional gases. Calcium oxide monocalcium fluoride can be added to remove additional sulfur at this stage when the oxygen potential has dropped to low levels. Generally, about 1-3 kg of CaO-CaF ₂ (90% CaO, 10% CaF ₂ ) can be added per ton of steel. In the course of one cycle, the above operations are completed in about 3-5 minutes. This operation helps to change the residual impurities into the form of calcium aluminate, which has a spherical shape which is optimal for steel products.

The composition of the finished steel discharged through outlet 399 after the calcium oxide-calcium fluoride treatment is shown in Table 1 below under the column labeled "refined steel". It is foreseeable that cleaner products than those listed in Table 1 can be obtained under varying conditions.

Table 1

Cupola Blowout Upper Chamber Blowout Spray Aluminum and Argon Refined Steel (Below)

Fe 95.42%

C 3.0% 0.1% 0.04%

S 0.03% 0.02% 0.015%

P 0.006% 0.015%

N 70ppm 30ppm 15-40ppm

O (dissolved) 150ppm 60ppm 6ppm

O (total) 17-35ppm

H 5ppm 2ppm

Cu 0.01%

Ti 0.01%

Mn 0.08% 0.40%

Cr 0.02%

Ni 0.02% 0.03% 0.02%

Si 1.45%

Figures 4 and 5 show an alternative arrangement. This arrangement is suitable for a substantially continuous flow of operating material from the cupola. For the apparatus shown in FIG. 4 , molten iron flows continuously from the cupola through conduit 400 into chamber structure 401 . Lime (ie mineral material) and oxygen may be injected into the sump by means such as pipe 404 as the stream of molten metal flows through the first chamber 402 to the laterally arranged second chamber 403 . Slag may be continuously discharged from the upper surface 405 of the molten iron by means such as a discharge port 410 .

The molten iron then flows into the second chamber 403 through the inlet 415 . In this chamber aluminum (ore) and argon (gaseous substance) are easily injected through means such as line 420 . Generally, it can be seen that the second chamber 403 is maintained under reduced pressure (partial vacuum). to facilitate the process. Calcium compounds are also sparged into the second chamber through line 421 with additional inert gas. As mentioned above, steel is produced as a result of the introduction of aluminum, argon, calcium oxide, calcium fluoride. The slag 425 floating on top of the steel product 426 is discharged through means such as a slag discharge, while at the end of the process the steel is easily discharged through an outlet 428 . In the schematic view of FIG. 4 , shown is a line 430 for feeding chamber 403 with argon and a line 431 for feeding chamber 402 with oxygen. Exhaust gases are readily removed from the system through lines 435 and 436 . These vented gases can be directed elsewhere in the process, such as to a steam generating plant, for efficient use. A heating coil is indicated at 440 . Ports 441 in bumps 442 allow passage of slag. The nubs 442 themselves create some agitation in the first chamber 402 to speed up refining. In Fig. 5, a cross-section representing the trough-like profile of the device 401 is shown.

It will be appreciated that while the multi-chamber refining units shown in Figures 3 and 4 each include two chambers, structures including more than two chambers may be provided in accordance with many of the principles of the invention.

A typical process of the present invention can be understood from the following suggested examples.

Advantageous device for carrying out the second stage under pressure

In an advantageous arrangement, the reduction of iron is carried out at greater than atmospheric pressure. The pressure of the gas represents actual energy. This energy can be tapped to drive high-pressure gas turbines in the third stage, boosting electricity production more efficiently. In an advantageous arrangement, the reduction is carried out at a relatively high pressure to enhance reduction and to enhance the benefit of obtaining pressurized output gas. This device also reduces the pressure of the molten metal, which overcomes the operational problems in a sense as described above.

The feed is supplied via conduit 661 to a pressurized cupola 660 as shown in FIG. The operating pressure is at least 50 psi (absolute pressure), and in some applications, the operating pressure range is preferably 250-300 psi (absolute pressure), depending on the characteristics of the feed material, temperature and flow rate. The feed melts before exiting a discharge hole 662 located at the bottom of the cupola 660 . Pressurized reducing air from compressor 696 is blown into cupola 660 via duct 692 through tuyeres 666 located above discharge holes 662 . The molten iron charge is then collected in the bath in the lower chamber 670 while still under pressure. The iron charge may be further refined in the lower chamber 670 . Gases and/or minerals are input at inlet 673 to facilitate refining. Slag formed on the surface flows away from the molten metal and exits through conduit 668 .

The remaining iron charge moves upward through the inlet 671 of a vertical discharge 672 having a conduit extending down into the molten iron so that the inlet 671 is submerged below the surface of the molten metal. The high pressure of the cupola 660 forces the molten iron up the vertical discharge 672 . As the pressure forces the molten metal up the vertical discharge 672, the weight of the metal counteracts the pressure of the gas, resulting in a lower top pressure as the molten metal rises. At an advantageous height, the weight of the metal has offset the top pressure so that the molten metal can flow out and be handled in a safer manner, thus overcoming the problems associated with handling pressurized molten metal. For cupola operation at 250-300 psig, the height of outlet 674 is about 50 feet above the level of molten iron in cupola lower chamber 670. However, vertical drain 672 performs the same function at any pressure greater than atmospheric pressure. The different heights of the discharge 672 allow the device to be adapted to other pressures, but if operating at constant pressure, the discharge 672 does not need to be adjustable. In one implementation, the outlet 674 is vertically adjustable for operation over the entire pressure range, but other methods of varying height may be used, such as using movable conduit sections.

In a preferred embodiment, the vertical drain as shown in FIG. 8 has a refractory lining 810 . The refractory lining 810 is advantageously surrounded by intermittently arranged heating coils or other heating means. The drain 672 preferably includes an insulating layer 814 to maintain the temperature above 2500°F to prevent the molten metal from freezing. When the molten iron reaches the top discharge port 674 of the vertical discharge device 672, the molten iron is at approximately atmospheric pressure and can be further refined as shown in Figures 3, 4 and 5.

FIG. 7 shows a cross-sectional view of the bottom 670 of the cupola 660 of FIG. 6 . The lower collar 710 of the discharge port 662 is surrounded by cooling water in the chamber 714 . The molten iron passes through the lower support ring 710 into the lower chamber 716. Oxygen from chamber 718 surrounding lower chamber 716 and methane from chamber 720 flow through conduits 722 and 724, respectively, to facilitate the refining process. From the lower chamber 716 the iron can enter various other further refining facilities.

Referring again to FIG. 6 , gas exiting the cupola 660 at greater than atmospheric pressure is exhausted through conduit 675 into a filter 680 and a desulfurizer 682 . The purified gas is then directed to a high pressure gas turbine 685 to produce electricity. The gas can then be passed through a second stage turbine (not shown) and/or further utilized in boiler 690 to generate steam for further electricity production. The turbine 685 may also be used to drive a compressor 696 that delivers pressurized gas to the cupola 660 . Exhaust gas produced in boiler 690 exits boiler 690 along 698 .

Example 1

In accordance with the present invention, the following provides a representative description of the operation of process equipment at a scale that is generally practical. It will be appreciated that a variety of equipment sizes and operating conditions may be used in accordance with the foregoing principles. For the described example, it can be estimated that the coal input to the system is about 90 tons per hour. For a typical coal feed, approximately 31 tons per hour of oil and 21 tons per hour of volatile gases are released from the extraction and pyrolysis process, resulting in 27 tons per hour of fine coke.

Agglomeration depends on the reducing properties of iron. If it contains iron ore such as taconite, about 13 tons per hour of the 27 tons of crushed coke per hour should be consolidated into pellets without taconite, this consolidation is by steam consolidation as described above , and provide enough water and lime to facilitate dough making. Approximately 14 tons per hour of crushed coke should be mixed with approximately 70 tons per hour of iron ore, 4.5 tons per hour of lime and 11.5 tons per hour of water to form approximately 100 tons per hour of pellets. Generally concurrent with the steam consolidation process, a drying step may be used to drive off the moisture in the pellets, resulting in approximately 90 tons per hour of ore-containing pellets being fed into the cupola, while 13 tons per hour of pellets containing no ore are fed into the cupola. The broken coke from the dough making is also sent into the cupola.

As mentioned above, cupolas can operate under a variety of conditions. For a typical process, about 116 tons per hour of combustion air are blown into the cupola to produce about 161 tons per hour of output gas, 18 tons per hour of slag and 40 tons per hour of reduced iron, i.e. pig iron, as described above , this pig iron can be easily converted into steel.

As the gases in the cupola are passed over the contents of the furnace, they are cooled very quickly. However, these gases are reheated to higher temperatures during the combustion process. This allows for efficient energy production through the gas turbine and subsequent boiler/steam system. This step can usually be accomplished using conventional equipment.

It will be appreciated that while certain specific implementations of the invention have been shown and described, the invention should not be limited to the particular apparatus described herein, except as defined in the following claims.

Claims (33)

1. A method for producing electrical energy with relatively efficient fuel utilization, said method comprising the following steps: (a) provide a coal fuel; (b) subjecting said coal fuel to a liquefaction process to remove oil and volatile matter therefrom, thereby producing a coke crushed product of coal; and (d) Production of electrical energy from the above-mentioned heat produced gas. 2. A method according to claim 1, wherein: (a) The above-mentioned liquefaction step comprises extracting the above-mentioned coal fuel with a solvent, followed by pyrolysis. 3. A method according to claim 2, wherein: (a) the above solvent is selected from the group comprising water and organic phenols; and (b) said pyrolysis comprising treating the extracted coal fuel at a temperature of at least about 600°C to drive off volatile materials therein. 4. The method of claim 1, wherein: (a) the said step of using the crushed coke product of said coal in a reduction and smelting process comprises mixing at least a portion of the crushed coke product of said coal with iron oxide material to form pellets, such mixing being carried out in order to reduce said material The iron is carried out in the presence of air. 5. A method according to claim 4, wherein: (a) The above heating step comprises heating to at least 1370°C in a cupola furnace. 6. The method of claim 5, wherein: (a) The above heating step in the cupola comprises heating at a pressure of at least 345,000 Pascals. 7. The method of claim 4, wherein: (a) said mixing comprises mixing said crushed coke product with said iron charge and a binder selected from the group consisting of silica, burnt lime, water and mixtures thereof. 8. The method of claim 1, wherein: (a) said step of producing electricity from said produced gas comprises passing said produced gas through a gas turbine to produce electricity and then through a boiler to produce steam; at least a portion of said steam is used to drive the turbine to produce electrical energy. 9. The method of claim 8, wherein: (a) said liquefaction step comprising extraction of said coal fuel with a hot solvent, followed by pyrolysis; and (b) the energy for heating said hot solvent and driving said pyrolysis is provided at least in part by said steam produced in said boiler utilizing said produced gas. 10. The method of claim 9, wherein: (a) The above-mentioned steps of using the above-mentioned crushed coke products in the reduction and smelting process include: (i) coke products of the gasification of the aforementioned coals; and (II) Passing gas from the crushed coke product of the aforementioned coal over the oxidized iron charge. 11. The method of claim 10, wherein: (a) Gasifying the coke product of the above coal includes heating the material in the presence of lime. 12. The method of claim 11, comprising: (a) passing said iron charge into a chamber in which the crushed coke product of said coal is gasified and melting said iron charge in that chamber; and (b) The step of introducing minerals and gases into the above-mentioned iron material for steel production comprises introducing the above-mentioned gas and minerals into the iron material while the above-mentioned iron material is still molten by the above-mentioned smelting. 13. A method according to claim 6, wherein said pressure is 1,700,000-2,100,000 Pascals. 14. The method of claim 6 including a step of reducing the head pressure of the reduced molten iron charge to approximately atmospheric pressure. 15. A method according to claim 14, wherein said step of reducing the pressure at the top of the molten iron comprises the step of utilizing gas pressure within the cupola to force said molten iron upwardly along a vertical discharge, whereby as the molten material rises, The pressure on the top of the molten iron is reduced. 16. The method of claim 15 wherein said step of reducing top pressure further comprises heating said vertical discharge means to maintain said molten iron in a flowable condition. 17. A process according to claim 1 wherein said coke coke product from step (b) is used as activated carbon and subsequent to said use the coke coke is used in the reduction step (c). 18. The method of claim 1, wherein said iron material comprises scrap iron. 19. A power plant comprising apparatus for the more efficient production of iron products from coal fuel, the plant comprising: (a) A coal liquefaction plant comprising an autoclave unit constructed and arranged for the extraction of oil from said coal fuel and an autoclave unit constructed and arranged for the removal of volatile substances from said coal fuel to form a coke product of coal and configured pyrolysis system; (b) a smelting furnace apparatus constructed and arranged for the reduction of iron oxide charges by the coke crushed product of said coal, the smelting furnace apparatus including means for forming hot product gases; systems for the production of steel; (c) a turbine system constructed and configured to be driven separately by said heat produced gases to produce electrical energy; (d) a steam boiler constructed and equipped to produce hot steam from said heat product gas; and (e) A heat exchanger device set up and configured in conjunction with the above coal liquefaction system, the purpose of which is to at least partially use the hot steam generated by the steam boiler to drive the liquefaction system. 20. A power plant according to claim 19 including means for pressurizing said melting furnace to about 1,700,000-2,100,000 Pascals. 21. A device used in a metal reduction process, said device comprising: (a) a cupola operable at pressures greater than atmospheric pressure, said cupola comprising a tower section for reducing said metal and a bottom section for collecting said reduced metal; and (b) A vertical discharge device comprising: (I) An inlet submerged in said molten metal collected in said bottom zone. (II) a vertical conduit rising from said bottom region; and (III) a discharge opening of said vertical conduit disposed in said bottom region, utilizing said operating pressure to force molten metal to move upwards along said vertical discharge means, so that as said molten metal rises, the weight of said metal counteracts said pressure, Thus as the metal rises, the pressure drops until the top pressure is equal to atmospheric pressure, allowing the metal to be further manipulated using conventional methods. 22. The apparatus of claim 21 including pressurization means for pressurizing said melting furnace to about 1,700,000-2,100,000 Pascals. 23. Apparatus according to claim 21, comprising: (a) a refining unit comprising means for directing a stream of molten iron from the bottom region of said cupola; said refining unit comprising means for selectively introducing mineral and gaseous charges; to facilitate the production of molten iron therefrom; steel. 24. The apparatus of claim 21 wherein said vertical discharge means includes means for maintaining said metal in molten flow. 25. Apparatus according to claim 24 including a vertically adjustable top discharge for adjusting the height of rise of said top discharge to allow said molten metal to flow out of said top discharge at a top pressure near atmospheric. 26. Apparatus according to claim 24, wherein said vertically adjustable top outlet includes means for adjusting in accordance with operating conditions of said cupola. 27. An apparatus for a metal reduction process, the apparatus comprising: (a) a cupola operable at pressures above atmospheric pressure, the cupola comprising a tower section for reducing said metal and a bottom section for collecting said reduced metal; (b) a multi-chamber refining unit comprising first and second vertically spaced reaction chambers; (i) said first reaction chamber is an upper chamber and includes ingate means for selective liquid flow communication with said cupola bottom region; (II) the above-mentioned second reaction chamber is a lower chamber which is generally disposed immediately below said upper chamber; (III) each of said first and second chambers includes a slagging device associated therewith; and (iv) each of said first and second chambers includes means for introducing the refining material into the molten material residing in the chamber; and (c) wherein said multi-chamber unit includes gate means for selectively passing the metal refined in the unit between said upper and lower chambers. 28. Apparatus according to claim 27, wherein: (a) said multi-chamber refining unit adapted to receive a substantially continuous flow of stream from said cupola bottom region; said multi-chamber unit comprising first and second laterally spaced stream chambers; (i) said first flow chamber is adapted to receive substantially continuously flow from said cupola and for passing substantially continuously therethrough to said second chamber; (ii) said second stream chamber is adapted to receive the stream from said first chamber and adapted to provide a substantially continuous outward flow of refined metal product from the chamber; (iii) each of said first and second chambers includes means for removing slag from the chamber; and (iv) Each of the aforementioned first and second chambers includes means for selectively introducing gas and mineral material into the chamber. 29. A method for more efficiently utilizing fuel to produce electrical energy, the method comprising the following steps: (a) provide a coal fuel; (b) subjecting said coal fuel to a process of liquefaction to remove oil and volatile matter therefrom to produce a coke product of coal; (c) the use of the above-mentioned coke crushed product of coal in a process at superatmospheric pressure for the reduction and smelting of iron material and the formation of hot product gas having a pressure above atmospheric pressure; (d) the use of the above-mentioned heat-produced gas having a pressure above atmospheric pressure for the production of electrical energy; (e) reducing the head pressure of the reduced molten iron from step (c) to near atmospheric pressure for safe and convenient handling of said molten iron. 30. A process according to claim 29 wherein step (c) is carried out at a pressure greater than 345,000 Pascals. 31. The method according to claim 29, wherein said step of lowering the top pressure of molten iron includes the step of using gas pressure to force said iron material to move upward along a vertical discharge device, so that as said molten iron material rises, said top pressure decreases, so that when rising When reaching the top discharge outlet of the above-mentioned vertical discharge device, the top pressure of the above-mentioned iron material is reduced. 32. The method of claim 31 wherein said step of reducing top pressure further includes heating said vertical discharge means to maintain said molten iron in a free-flowing condition.

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