Systems and methods for carbothermically producing aluminum
Inactive Publication Date: 2008-01-24
ARCONIC INC +1
View PDF17 Cites 9 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
[0005]In view of the foregoing, a broad objective of the present invention is to provide systems and methods for carbothermically producing aluminum with restricted loss of aluminum to vapor off-gas.
[0006]In addressing one or more of the above objectives, the present inventor has recognized that a sufficiently deep reactor may be used, wherein the hydrostatic pressure due to the depth of the molten liquid within the reactor acts to suppress the aluminum vapor producing reactions. The present inventors have further recognized that such a deep reactor facilitates the use of a plurality of horizontally and / or vertically spaced heating electrodes, thereby enabling different heating rates within the reactor.
[0007]In one aspect of the present invention, a system for carbothermically producing aluminum is provided, the system comprising a reactor having a bottom, sidewalls and a top defining a reaction chamber, a plurality of heating electrodes extending from the sidewalls, and a vapor recovery unit fluidly interconnected to the reaction chamber. The sidewalls of the reactor are of a sufficient height such that when the reactor is operated and contains molten liquid, the total pressure within the reaction chamber, as measured proximal the bottom of the reactor, is at least about 1.50 atm. Thus, the hydrostatic pressure due to the molten liquid should be at least 0.5 atm, such as at least about 0.75 atm or even at least about 1 atm, thereby producing total pressures within the reaction chamber of at least 1.5 atm, such at least about 1.75 atm, or even at least about 2 atm, as measured proximal the bottom of the reactor. These increased pressures suppress aluminum vapor forming reactions, thereby increasing aluminum production efficiency.
Problems solved by technology
Cochran does not disclose methods of suppressing vapor reactions outside of this scope.
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
examples
[0031]A computerized program (FACTSAGE, Thermfact / CRCT, Montreal, Canada and GTT-Technologies, Herzogenrath, Germany) was utilized to simulate the effect of increased pressures in the operation of the carbothermic reactor. The results from the simulation are given below in Table 1. FIG. 3 graphically illustrates the effect of increased pressure relative to aluminum production. FIG. 4 graphically illustrates the effect of increased pressure relating to gas phase composition. More aluminum metal and CO gas are produced and less aluminum vapor species, Al(v) and Al2O (v), are produced. The program validated that increased pressures within the reactor would result in increased aluminum metal production with decreased aluminum vapor production.
TABLE 1OutputPressureTemperatureGasGasAlloySlagCarbideGraphite(atm)(K)(moles)CO (%)Al2O (%)Al (%)(moles)(moles)(moles)(moles)124003.3475.81410.20.1500.1501.524003.2278.714.56.80.3400.140224002.7882.612.54.800.160.190124503.4676.513.210.21000.181.52...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
| Property | Measurement | Unit |
|---|---|---|
| Hydrostatic pressure | aaaaa | aaaaa |
| Hydrostatic pressure | aaaaa | aaaaa |
| Hydrostatic pressure | aaaaa | aaaaa |
Login to View More
Abstract
Systems and associated methods for carbothermically producing aluminum are provided, the systems generally including a reactor having a depth such that when the reactor contains molten liquid hydrostatic pressure of the molten liquid is at least about 0.5 atm as measured proximal the bottom of the reactor. A plurality of horizontally disposed electrodes, which may be offset from one another in a vertical and / or horizontal direction, may also be used in accordance with the system to provide selective heating gradients within the molten liquid.
Description
FIELD OF THE INVENTION[0001]The present invention relates to systems and methods for carbothermically producing aluminum, specifically using increased pressure.BACKGROUND OF THE INVENTION[0002]The direct carbothermic reduction of alumina has been described, for example, in U.S. Pat. No. 2,974,032 to Grunert et al., as having an overall reaction of:Al2O3+3C→2Al+3CO (1)This reaction (1) takes place, or can be made to take place, in two steps:2Al2O3+9C→Al4C3+6CO (2)Al4C3+Al2O3→6Al+3CO (3)[0003]Reaction (2) takes place at temperatures below 2000° C. and generally between 1900° C. and 2000° C. Reaction (3) takes place at appreciably higher temperatures (e.g., above 2060° C.). In addition to the species stated in reactions (2) and (3), volatile species including gaseous Al and gaseous aluminum suboxide, that is Al2O, may be formed, such as via one or more the following reactions:Al2O3+2C→Al2O(v)+2CO (4)Al2O3+3C→2Al(v)+3CO (5)It is highly desirable to suppress these vapor forming reac...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More IPC IPC(8): C22B4/00C22B4/02
CPCC22B4/02C22B21/02C22B5/10
InventorCHRISTINI, ROY A.
OwnerARCONIC INC