This referenced patent discloses a method and apparatus for practicing carbonaceous-based metallurgy, and in the specific case of making liquid iron, two distinct steps are involved. The first step comprises the formation of an iron/carbon product in a horizontal tubular reactor wherein a gas containing oxygen is injected from a horizontal lance inserted from the discharge end of the horizontal reactor while the hot iron/carbon product (intermediate) formed is discharged into a vertical reactor. The second step comprises the melting of the iron/carbon product in the vertical reactor, called a “melter/homogenizer,” by means of the injection of a gas containing oxygen using a vertical lance to convert iron/carbon product into liquid iron which is fed into a holding reservoir. Specifically, the instant invention relates to improvements made to the referenced patent as it relates to the making of liquid iron comparable to liquid iron produced in a blast furnace, which is commonly known in the steel industry as “Hot Metal.”
The steel industry in March 1998 issued a comprehensive publication entitled “Steel Industry Technology Roadmap,” and on page 11, it states the following:
To put the concept into practice, a pilot was constructed (Exhibit 2) and tests were initiated. A multitude of problems were discovered. The most serious problems consisted of the following:
No 1. Sporadic explosions caused by super-heated steam generated from water leakage from the melt-down of the stainless steel outer tube (sheath) at the copper tip of the water-cooled, oxygen injection lance (Exhibit 3), which endangered operating personnel, one of whom experienced severe burns, necessitating a hospital stay. To prevent the melting of the stainless sheath, steps were taken to increase the size of the copper tip. Unfortunately, excessive build-up at the tip of the lance occurred (Exhibit 4), resulting in destroying the flow pattern of the oxygen.
No 2. The uniform flow of the gas containing oxygen from the tip of the lance is most critical in order to produce a uniform product, an iron/carbon intermediate of some 50% metallization with about 6% carbon is suitable for conversion into carbon-saturated liquid iron of blast furnace specification. The problems caused by the build-up at the tip of the lance included premature melting, over-oxidation, too low in metallization, and completely unreduced feed material:
No 3. Excessive heat loss occurred within the horizontal reactor, especially toward its discharge end, caused by the cooling effect from the water-cooled lance.
No 4. Build-up at the discharge end of the horizontal reactor itself persisted (Exhibit 5), resulting in a physical blockage that prevented the advancement of the contents of the horizontal reactor by means of the pushing ram of the charger, thus forcing unscheduled shutdowns.
No 5. Build-up downstream of the horizontal metalizing reactor and upstream of the storage was also experienced in the vertical section where the homogenizer/melter would be located, causing shutdowns that entailed moving equipment to provide access to poke hot, built-up material with a bar to unplug the build-up; Exhibit 6.
No 6. Iron/carbon intermediate that was fed to the melting furnace, being lighter than the liquid iron, would float on top of the molten bath (Exhibit 7) and dwell there, instead of entering into solution with the metal in the molten bath, such flotation of intermediate preventing the rapid and complete conversion of the intermediate into liquid iron.
In addressing problems No 1, No 2, and No 3, it was decided to relocate the injection lance to be introduced from the cold end through the charger of the horizontal metallizing reactor, as shown in Exhibit 8, together with increasing the pressure of injection of the gas containing the oxygen to create a forceful jet from the tip of the lance to reach all the way to the discharge end of the horizontal metalizing reactor, with the tip of the lance being located where the temperature of the iron ore and ash are below their incipient fusion. This required the construction of a new charger (Exhibit 9), wherein a provision was made for the lance to pass through the center of the mandrel, resulting in a structure of the lance being disposed through the mandrel and the mandrel through the pushing ram.
In addressing problem No 4, which relates to the blockage created by build-up at the discharge end of the metallizing reactor, the new charger was constructed structurally more robust than the initial one, and also the hydraulic pressure was raised by adding a booster hydraulic pump with new controls (Exhibits 10A and 10B) to increase the pushing force of the new charger in order to surmount blockage.
In addressing problem No 5, to prevent build-up downstream of the metalizing reactor and upstream of the storage, it was decided to completely eliminate the homogenizer/melter (numeral 11), described in the referenced patent, and perform the melting of the iron/carbon intermediate in an induction channel furnace (ICE) as that made by Ajax Magnethermic, with certain modifications as would be described in detail hereinafter, to serve both as a melter as well as storage of liquid iron.
In addressing the issue of the intermediate flotation on top of the molten bath, a vertically oscillating mechanical dunker was developed (Exhibit 11A) which was equipped with a graphitic block (Exhibit 11B) which is adapted to force the floating intermediate to be submerged below the level of the high-temperature bath where the carbon in the intermediate completes the reduction of the unreacted oxides of iron, namely, Fe2O3, Fe3O4, and FeO, which have not reacted in the horizontal metallizing reactor.
With the changes made, the Applicant was successful in overcoming the problems mentioned hereinbefore and producing an acceptable intermediate into which carbon from the coal is integrally imbedded within the metallized iron made from ore fines or concentrate in the horizontal metalizing reactor (Exhibit 12).
Further, two valuable gases are co-produced: one during the metallization of the iron ore in the horizontal metallizing reactor and a second during the melting of the intermediate (Exhibit 13).
To summarize the above, the Applicant, in effect, has invented a method and apparatus adapted to accept various proportions of ore and coal and yet produce a liquid iron (Exhibit 13) by way of producing an intermediate whose composition is quite suitable to be converted to liquid iron that can be subsequently converted into low-cost steel.
The main object of this invention is to produce liquid iron directly from ore fines and concentrate using low-cost coal consistent with the Ultimate Objective stated in the Steel Industry Technology Roadmap of March 1998, mentioned above.
Another object of the present invention is to provide an efficient method and apparatus to carry out same for converting an iron ore and coal mix into liquid iron at an efficiency greater than the conventional process of making liquid iron in a blast furnace that uses coke and iron ore pellets.
Therefore another object of the instant invention is to provide a method and apparatus that greatly reduce heat loss when compared with the conventional process of making liquid iron in a blast furnace that uses coke and iron ore pellets.
Still another object of the instant invention is to provide a method and apparatus that greatly reduce emissions when compared to conventional processes that feed pellets, sinter, and coke into a blast furnace, which in turn is a major emitter of carbon dioxide (CO2).
Further another object of the present invention is making an induction channel furnace (ICF) more efficient while still protecting its lining by providing dunking means which assist in submerging an iron/carbon intermediate into the molten iron bath in the ICF in order to expedite its reaction and cause it to blend with the constituents in the molten iron bath to result in its rapid liquifaction and assimilation within the molten iron bath.
Further still another object of the present invention is to physically integrate an induction channel furnace (ICF) to a steelmaking furnace, such as to a basic oxygen steelmaking furnace or to an electric arc steelmaking furnace, known in the industry as BOF and EAF, respectively, but by way of example, the description that follows will disclose the integration of the ICF to the BOF, the ICF being adapted to convert an iron and carbon intermediate into molten iron while the BOF converts molten iron and scrap into steel. The ICF and the BOF are joined together structurally in such a way as to result in a hybrid, dual-purpose configuration that reduces capital and operating costs, increases efficiency, and minimizes emissions.
Further yet another object of the present invention consists in providing a physical interconnection between the ICF and the BOF to enable the direct pouring of molten iron directly from said ICF in said BOF by revolving both said ICF and said BOF radially without necessitating the use of a crane.
It is still another object of the present invention to provide an ICF per se in the case of making molten iron only in situations where an improved method of iron making is required without the production of steel.
It is therefore another object of the present invention to provide a method and apparatus that can convert carbon dioxide (CO2), a greenhouse gas, into a useful product such as fertilizer.
Other objects of this invention will appear from the following description and appended claims. Reference is made to the accompanying drawings which describe certain apparatus structures to practice this method of making an iron/carbon intermediate which is converted to liquid iron, which is subsequently converted into steel. It is to be understood that the method and apparatus disclosed herein are not limited solely to the processing of iron-bearing ore, as the invention can also be applied to other non-iron bearing ores.
Before describing in detail the present invention, it is to be understood that this invention is not limited to the details or arrangement of the parts illustrated in the attached drawings, as the invention can be operative by using other embodiments. Also, it is to be understood that the terminology herein contained is for the purpose of description and not limitation.
In describing the plant in more detail, the Applicant will describe only battery 20(a) and furnace A, since the two batteries and the two furnaces are identical.
Beneath each battery, two conveyors, marked by numerals 22(a) and 23(a), are disposed, with conveyor 22(a) being fixed, and conveyor 23(a) is adapted to travel as a shuttle conveyor. Shuttle conveyor 23(a) is adapted to travel not only to furnace A, but also all the way to the end of furnace B, in order to provide redundancy. Furnace A possesses three identical feed openings, marked by numeral 24, equally spaced along the length of both furnaces to enable shuttle conveyor 23(a) to distribute hot iron/carbon intermediate along the length of furnace A as well as furnace B. At the head of shuttle conveyor 23(a), a dunker, marked by numeral 25, is disposed to immerse into the molten bath, iron/carbon intermediate that is fed into furnace A or furnace B. It is to be noted that shuttle conveyor 23(b) can service both furnace A and furnace B.
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Since the method of metallization and melting has been described in detail above,
With respect to the application of this invention to the non-ferrous metals, variations to that which is disclosed herein, can take place; however, the intention is not to depart from the spirit of this disclosure. All in all, it is submitted, herein that the instant invention provides major improvement over conventional practice/metallurgy, which can use low-cost raw materials, and which is energy efficient and environmentally friendly, while requiring low capital investment.
The present invention relates to the making of iron and steel and is an improvement over Applicant's U.S. Pat. No. 6,409,790 B1, issued on Jun. 25, 2002, hereinafter referred to as the “referenced patent.”