BACKGROUND
1. Field of the Disclosure
This disclosure relates generally to the field of molten oxide electrolysis on the Moon, other planetary bodies, in the vacuum of space, and in planetary atmospheres to produce products, including oxygen, iron, aluminum, magnesium, silicon and/or concentrated oxide slag.
2. Description of the Related Art
Several methods have been proposed to process lunar regolith on the Moon for extraction of materials from lunar regolith; however, these methods all require chemical reagents which must be transported from Earth to the Moon. The constraints on Earth-launched payload size and weight prohibit economic and efficient use of such methods on the Moon, which require transportation of the chemical reagents to the Moon.
BRIEF SUMMARY
The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the subject matter disclosed herein. This summary is not an exhaustive overview of the technology disclosed herein. It is not intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
In one exemplary embodiment, a system for molten extraction of oxygen and metals from metal oxide feedstock: a molten electrolyte reactor which comprises at least one heat source to initially melt the metal oxide feedstock, at least one anode, at least one cathode, and through an electrolysis reaction the molten electrolyte reactor produces at least an electrochemically extracted metal, a liquid metal oxide slag, and oxygen gas; a silicon refiner reactor in fluid communication with the molten electrolyte reactor to receive at least a portion of the electrochemically extracted metal containing as a minimum silicon metal from the molten electrolyte reactor, the silicon refiner reactor including at least one heat source, at least one anode, at least one cathode and through an electrolysis reaction produces at least substantially pure liquid silicon; and an aluminum refiner reactor in fluid communication with the molten electrolyte reactor to receive at least a portion of the liquid metal oxide slag from the molten electrolyte reactor, the aluminum refiner reactor including at least one heat source, at least one anode, at least one cathode, and through an electrolysis reaction produces at least substantially pure liquid aluminum and oxygen gas.
In another exemplary embodiment, a method for molten electrolysis of metal oxides may comprise: providing a molten electrolyte reactor which reactor comprises at least one heat source, at least one anode, at least one cathode, and a quantity of metal oxide feedstock disposed within the molten electrolyte reactor; operating the at least one heat source to melt the quantity of metal oxide feedstock into a quantity of molten metal oxide feedstock within the molten electrolyte reactor; applying a voltage to the at least one anode and the at least one cathode to force a current to pass between the at least one anode and the at least one cathode and through the molten metal oxide feedstock, to produce at least an electrochemically extracted metal, a liquid metal oxide slag, and oxygen gas; providing a silicon refiner reactor which comprises at least one heat source, at least one anode, and at least one cathode; disposing the silicon refiner reactor in fluid communication with the molten electrolyte reactor to receive at least a portion of the electrochemically extracted metal from the molten electrolyte reactor; operating the at least one heat source in the silicon refiner reactor to melt at least a portion of the electrochemically extracted metal; applying a voltage to the at least one anode and cathode of the silicon refiner reactor to force a current to pass between the at least one anode and cathode and through the molten electrochemically extracted metal in the silicon refiner reactor, to produce at least substantially pure liquid silicon plus other possible metal; providing an aluminum refiner reactor, which comprises at least one heat source, at least one anode, at least one cathode; disposing the aluminum refiner reactor in fluid communication with the molten electrolyte reactor to receive at least a portion of the metal oxide slag produced by the molten electrolyte reactor; operating the at least one heat source in the aluminum refiner reactor to melt at least a portion of the metal oxide slag; and applying a voltage to at least one anode and cathode of the aluminum refiner reactor to force a current to pass through the melted metal oxide slag to produce at least substantially pure liquid aluminum and oxygen gas.
BRIEF DESCRIPTION OF THE DRAWING
The present method and system for molten regolith electrolysis on the Moon and other planetary bodies, in the vacuum of space, and on planetary atmospheres may be understood by reference to the following description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a front view of system for molten regolith electrolysis on the Moon in the vacuum of space in accordance with an illustrative embodiment of the invention;
FIG. 2 is a rear view of the system of FIG. 1;
FIG. 3 is a top view of the system of FIG. 1;
FIG. 4 is a perspective view of the system of FIG. 1;
FIG. 5 is a perspective view of a molten regolith electrolysis reactor which is a portion of the system of FIG. 1;
FIG. 6 is a top view of the molten regolith electrolysis reactor of FIG. 5;
FIG. 7 is a partial cross-sectional view of the molten regolith electrolysis reactor of
FIG. 6, taken along line 7-7 of FIG. 6;
FIG. 8 is a rear view of the molten regolith electrolysis reactor of FIGS. 5 and 6;
FIG. 9 is a side view of the molten regolith electrolysis reactor of FIG. 8;
FIG. 10 is a perspective view of a silicon refiner reactor, which is a portion of the system of FIG. 1;
FIG. 11 is a top view of the silicon refiner reactor of FIG. 10;
FIG. 12 is a partial cross-sectional view of the silicon refiner reactor of FIG. 11, taken along line 12-12 of FIG. 11;
FIG. 13 is a perspective view of an aluminum refiner reactor, which is a portion of the system of FIG. 1;
FIG. 14 is a top view of the aluminum refiner reactor of FIG. 13; and
FIG. 15 is a partial cross-sectional view of the aluminum refiner reactor of FIG. 14 along line 15-15 of FIG. 14.
While certain embodiments of the present method and system will be described in connection with the present exemplary embodiments shown herein, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by claims to be filed in a subsequent non-provisional patent application. For example, reactors used in the vacuum of space or on the Moon may also be on Earth, or vice versa. In the drawing figures, which are not to scale, the same reference numerals are used throughout the description and in the drawing figures for components and elements having the same structure, and primed reference numerals are used for components and elements having a similar function and construction to those components and elements having the same unprimed reference numerals.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
It should be understood that, although an illustrative implementation of one or more exemplary embodiments are provided below, the various specific exemplary embodiments may be implemented using any number of techniques known by persons of ordinary skill in the art. The disclosure should in no way be limited to the exemplary embodiments, drawings, and/or techniques illustrated below, including the exemplary designs and implementations illustrated and described herein. Furthermore, the disclosure may be modified within the scope of the appended claims along with their full scope of equivalents.
Colonization of space, along with the in-space industrialization needed to support it, holds immense potential; however, neither will be possible if the air we breathe, the fuel that propels our spacecraft, and the materials with which we build with must be transported from Earth as the constraints on Earth-launched payload size and weight prohibit economic development of space. The solution is to utilize the materials, e.g., on the Moon. Lunar regolith, the deep dust that covers the lunar surface, is rich in the major elements needed to sustain life, support manufacturing, enable energy generation, and advance the exploration of space.
Lunar regolith is the material covering the lunar surface ranging from 0.5 m.-15 m. in depth. Relatively homogenous in its composition, lunar regolith is composed mainly of oxides of silicon, aluminum, iron, titanium, magnesium, and calcium, with its specific composition, e.g., depending on its location such as on the Moon, as lunar regolith has some variation in composition throughout the lunar surface. From the regolith samples brought back to earth from prior lunar missions, two categories or regolith types have been named: Highland and Mare. Two samples that represent these categories well are the Apollo 16 Sample #64501 (Highland) and the Luna 24 Sample #24999 (Mare). The compositions of these samples are given in the chart below.
|
Missing Sample
|
Apollo 16
Luna 24
|
#64501
#24999
|
Terrain
|
Highland
Mare
|
Location
|
Descartes
Mare
|
Highland
Crisium
|
Regolith Composition %
|
|
SiO2
45.42
44.61
|
TIO2
0.45
0.99
|
AI2O3
27.85
10.77
|
Cr2O3
0.08
0.42
|
FeO
4.49
20.83
|
MnO
0.06
0.28
|
MgO
4.39
10.97
|
CaO
16.77
10.87
|
Na2O
0.4
0.23
|
K2O
0.09
0.02
|
P2O3
0
0
|
S
0
0
|
Total %
100
99.99
|
|
While the following description is directed to processing of regolith, the systems and methods disclosed herein can be used to process any suitable metal oxide feedstocks. Example metal oxide feedstocks may include any suitable source of metal oxide, including, but not limited to, a mineral ore, gravel, regolith, natural deposit, a hematite including hydrothermal, metamorphic, and volcanic deposits, for example, and other sedimentary materials, etc., magnetite, goethite, limonite, on-earth regolith, off-earth regolith, celestial ore, lunar regolith, Martian regolith etc., to use non-limiting examples. A metal oxide feedstock may comprise metal oxide in any suitable amount, for example, between 0.1 wt. % to about 5 wt. %, about 5 wt. % to about 15wt. %, about 15 wt. % to about 35 wt. %, about 35 wt. % to about 65 wt. %, about 65 wt. % to about 85 wt. %, about 85 wt. % to about 99 wt. %, or any ranges therebetween. Metal oxides in the feedstocks may include, for example, Lithium oxide (Li2O), Beryllium oxide (BeO), Sodium oxide (Na2O), Magnesium oxide (MgO), Aluminum oxide (Al2O3), Potassium oxide (K2O), Calcium oxide (CaO), Scandium oxide (Sc2O3), Titanium dioxide (TiO2), Vanadium pentoxide (V2O5), Chromium oxide (Cr2O3), Manganese dioxide (MnO2), Iron(II) oxide (FeO) and Iron(III) oxide (Fe2O3), Cobalt(II) oxide (CoO) and Cobalt(III) oxide (Co2O3), Nickel(II) oxide (NiO), Copper(I) oxide (Cu2O) and Copper(II) oxide (CuO), Zinc oxide (ZnO), Gallium oxide (Ga2O3), Rubidium oxide (Rb2O), Strontium oxide (SrO), Yttrium oxide (Y2O3), Zirconium dioxide (ZrO2), Niobium pentoxide (Nb2O3), Molybdenum trioxide (MoO3), Ruthenium dioxide (RuO2), Rhodium(III) oxide (Rh2O3), Silver oxide (Ag2O), Cadmium oxide (CdO), Indium oxide (In2O3), Tin(II) oxide (SnO) and Tin(IV) oxide (SnO2), Antimony(III) oxide (Sb2O3) and Antimony(V) oxide (Sb2O5), Cesium oxide (Cs2O), Barium oxide (BaO), Hafnium dioxide (HfO2), Tantalum pentoxide (Ta2O5), Tungsten trioxide (WO3), Rhenium(VII) oxide (Re2O7), Osmium tetroxide (OsO4), Iridium(IV) oxide (IrO2), Gold(III) oxide (Au2O3), Thallium(I) oxide (Tl2O) and Thallium(III) oxide (Ti2O3), Lead(II) oxide (PbO) and Lead(IV) oxide (PbO2), Bismuth(III) oxide (Bi2O3), and any combination thereof.
With reference to FIGS. 1-4, a system 100 is shown for molten regolith electrolysis on the Moon in lunar vacuum in accordance with an illustrative embodiment. System 100 generally includes: a molten regolith electrolysis reactor 101 which through an electrolysis reaction with metals extraction based on Gibbs Free Energy produces an electrochemically extracted metal-initially Fe—Si, a liquid metal oxide slag, and oxygen gas; a silicon refiner reactor 201 in fluid communication with the molten regolith electrolysis reactor 101 to receive the electrochemically extracted metal from the molten regolith electrolysis reactor 101 and which through an electrolysis reaction the silicon refiner reactor 201 produces substantially pure liquid silicon; and an aluminum refiner reactor 301 in fluid communication with the molten regolith electrolysis reactor 101 to receive the liquid metal oxide slag from the molten regolith electrolysis reactor 101, and which through an electrolysis reaction, the aluminum refiner reactor 301 produces substantially pure liquid aluminum, gaseous magnesium, and oxygen gas. As used herein, substantially pure refers to at least 80 wt. % or greater. As shown in FIGS. 1-4, the molten regolith electrolysis reactor 101, the silicon refiner reactor 201, and the aluminum refiner reactor 301 are each supported on the lunar regolith 50 of the lunar surface 51 of the Moon 52 by a suitable support structure, or frame, 53, 53′, 53″, which may have different or the same heights.
Still with reference to FIGS. 1-4, suitable piping is provided between the reactors 101, 201, 301 to place the molten regolith electrolysis reactor 101 in fluid communication with the silicon refiner reactor 201 and with the aluminum refiner reactor 301. The molten regolith electrolysis reactor 101 is provided with: piping 102 which exits from the molten regolith electrolysis reactor 101 and is in fluid communication with piping 202 which enters the silicon refiner reactor 201; and piping 103 which exits from molten regolith electrolysis reactor 101 and is in fluid communication with piping 302 which enters the aluminum refiner reactor 301. The manner in which piping 102 is connected to piping 202, and piping 103 is connected to piping 302, and other piping connections are made will be hereinafter described in greater detail.
With reference to FIGS. 3, and 5-9, the molten regolith electrolysis reactor 101 of system 100 is shown to include a housing 105 having an inner wall surface 106, and an outer wall surface 107. The inner wall surface includes a layer 108 of thermal insulation material, which preferably is a castable ceramic refractory material having the requisite strength and thermal conductivity characteristics to serve as a high temperature thermal insulator for use in a molten regolith or metal oxide electrolysis reactor. As shown in FIG. 7, the layer 108 of thermal insulation material on the inner wall surface 106 of housing 105 defines, or forms, an internal reaction volume space 109 within housing 105, wherein molten regolith can be contained and an electrolysis reaction may occur, as will be hereinafter described in greater detail. Preferably the internal reaction volume space 109 has a generally cylindrical configuration.
As shown in FIGS. 3 and 5-9, and in particular FIGS. 6 and 7, housing 105 preferably has a generally cylindrical configuration and preferably has a housing lower portion 110 and a lid 111 which mates with the lower portion 110. Preferably, housing 105 and lid 111 are made from stainless steel, or any other material that has the requisite strength and thermal characteristics to withstand the high temperature present in the molten regolith electrolysis reactor 101 during the electrolysis of regolith 50, and to be exposed on the lunar surface 51 in the Moon's vacuum environment. Lid 111 preferably also includes a layer 108′ of thermal insulation material which preferably is also a castable ceramic refractory material. Lid 111 of housing 105 includes piping 114 which includes a flange 115, and piping 114 is secured, as by welding, to the top of lid 111. Flange 115 is fixedly secured to piping 114 by welding. A translation, or movement, generator 116, having a flange 117 at the top of the translation generator 116 and a flange 118 at the bottom of movement generator 116, is supported by a translation generator support 124. Flange 118 is fixedly secured to flange 115 by a plurality of bolts 119 connecting flanges 115 and 118 together. Flanges 115, 117, and 118 are high temperature sealed ultrahigh vacuum flanges which provide a seal that can withstand ultrahigh vacuum, e.g., as on the Moon which is approximately at pressure of 10-10Torr to 10-11 Torr, whereby in combination with other high temperature sealed ultrahigh vacuum flanges used in molten regolith electrolysis reactor 101, as will be hereinafter described, the interior of housing 105 and translation generator 116 are sealed off from the vacuum environment of the lunar surface.
Molten regolith electrolysis reactor 101 includes at least one anode 120 and at least one cathode 130 to perform the electrolysis reaction within the internal reaction volume space 109. Preferably, anode 120 is made of a chemically inert and high temperature stable conducting material or is a high temperature stable conducting material coated with a nearly inert material such as iridium. The at least one anode 120 includes an electrical connector 121 attached to the upper end 122 of anode 120, to transmit an electric current to the anode 120, from a suitable electric power source, not shown. Suitable high temperature sealed ultrahigh vacuum seals provide a seal between the electrical connector 121 and flange 117 of movement generator 116 from the vacuum of space. The lid 111 and the lower portion 110 of housing 105 are provided with high temperature sealed ultrahigh vacuum flanges 140, 141, secured together with a plurality of bolts 142, or other suitable fasteners.
Still with reference to FIGS. 3 and 5-9, the at least one anode 120 is disposed within the housing 105 and is moveable within the internal reaction volume space 109 as will be hereinafter described. Anode 120 is disposed, or placed, within a compressible, flexible metal bellows 123. The at least one cathode 130 is disposed, or placed, within housing 105, with at least a portion of the at least one cathode 130 being disposed within the internal reaction volume space 109. The at least one cathode 130 may include a plurality of cathode rods 131 with the ends 132 of the cathode rods 131 being disposed in the internal reaction volume space 109 in contact with molten regolith 50′ contained within the internal reaction volume space 109, as will be hereinafter described. The bottom of the lower portion 110 of housing 105 includes piping 114′ which includes a flange 115′; and piping 114′ is secured to the bottom of the lower portion 110 of housing 105 as by welding. Flange 115′ is fixedly secured to piping 114′ as by welding. A flange 118′ is secured to flange 115′ by a plurality of bolts, and electrical connector 121′ passes through flanges 115′ and 118′ to provide electric current to cathode 130. Flanges 115′ and 118′ are high temperature sealed ultrahigh vacuum flanges as previously described.
Still with reference to FIGS. 3 and 5-9, flange 117 and flange 118 of the movement generator 116 are connected by the compressible, flexible metal bellows 123, which permits motion, or movement, of flange 117 and the electrical connector 121 attached to the upper end 122 of anode 120. Three motor drivers, or motors, 125 associated with the translation, or movement, generator 124, move the translation generator 124 either up and down in a direction parallel to the longitudinal axis 130′ of cathode 130, or in directions perpendicular to the longitudinal axis 130′ of cathode 130. The movement, or translation, of the translation generator 124, in turn can cause the upward or downward movement of anode 120 within the internal reaction volume space 109. This vertical motion is important for control of the voltage applied for the electrolysis reaction. The separation of the anode and cathode as controlled by the vertical notion of the translation generator 124 defines the voltage drop across the molten regolith and hence the energy dissipated in the molten regolith through heating. Changing the anode to cathode separation changes the amount of energy dissipated and hence the temperature of the molten regolith. In addition to vertical motion, the translation generator 124 can also cause a side-to-side movement of the anode 120 within the internal reaction volume space 109. As the electrolysis reaction in the internal reaction volume 109 will cause oxygen molecules to be produced by the anode 120, the foregoing described movement of the anode 120 may assist in mixing of molten regolith 50′ within the internal reaction volume space 109 and may assist in releasing any trapped oxygen molecule bubbles found under the horizontal anode base plate 126 associated with the lower end 127 of anode 120 to cause such bubbles to move from underneath the anode base plate 126 toward the inner wall surface 128 of the internal reaction volume space 109, and then move, or float, upwardly in the molten regolith 50′ to the top of the molten regolith 50′, so that the oxygen molecules may later be removed from the molten regolith electrolysis reactor 101 as will be hereinafter described. Alternatively, the anode base plate 126 attached to the lower end 127 of anode 120 and disposed perpendicular to the longitudinal axis 120′ of anode 120 could be tilted, or disposed at an acute angle, with respect to the longitudinal axis 120′ of anode 120. Upward and downward movement of translation generator 124 and anode 120 will then mix the molten regolith 50′ and assist in releasing any trapped oxygen molecule bubbles formed under the tilted anode base plate 126′, as previously described. A further embodiment for movement of oxygen gas from underneath the anode applies the principal of dielectrophoresis to achieve acceleration and movement of gas bubbles from under the anode through the application of electric fields. This is accomplished by inserting electrodes near the anode of appropriate size and configuration to which voltage is applied so as to generate a force on oxygen bubbles that will sweep the bubbles from under the anode toward the inner wall of the reactor from which they can float to the top of the melt under the presence of a gravitational field.
Still with reference to FIGS. 3 and 5-9, the molten regolith electrolysis reactor 101 includes at least one heat source which may be a heater 150 which is used to initially melt regolith 50, which has been loaded into reactor 101 and into the internal reaction volume space 109 (FIG. 7). A heat source may be any suitable source of heat, including a separate heater, current traveling between an anode and a cathode, or both. Preferably a plurality of heaters 150 are disposed within the housing 105 with a portion of each heater 150 disposed in the internal reaction volume space 109. In the embodiment of the molten regolith electrolysis reactor 101 illustrated, eight heaters 150 are utilized and a portion of each heater, or the ends 151 of each heater 150 are disposed, or placed within, the internal reaction volume space 109. The heaters 150 preferably are spaced radially around the housing 105. Each heater 150 is powered by an electric current which may be passed through two copper power feed rods 152, or other suitable electrical connectors, into a wire coil heater element 153 to create and supply heat energy to melt the regolith 50 in the internal reaction volume space 109. Each heater 150 is disposed in housing 105 through a piping 154 fixedly secured to the outer wall surface 107 of housing 105 as by welding, which piping 154 is sealed by a high temperature sealed ultrahigh vacuum flange 155, which includes suitable seals for the power connectors 152 which pass through flange 155; and then via a passageway 156 formed in the thermal insulation layer 108 extending from the inner surface wall surface 106 of housing 105 into the internal reaction volume space 109.
At least one temperature sensor 160, such as a thermocouple, may be provided to permit the temperature of the regolith melt 50′ within the internal reaction volume space 109 to be measured and monitored. As shown in FIGS. 3 and 5-9, two or more temperature sensors 160 may be utilized. Each temperature sensor 160 can pass anywhere through the reactor wall into the internal reaction volume space 109, and as example here through the lid 111 of reactor 101 into the internal reaction volume space 109 in the same manner as the heaters 150 are disposed within the internal reaction volume space 100, including piping 154′, high temperature sealed ultrahigh vacuum flange 155′, and passageway 156′. At least one liquid level sensor 170 may be provided to measure and monitor the level of the liquid reduced liquid metal in the internal reaction volume space 109. One liquid level sensor 170 is shown passing through the outer wall surface 107 of housing 105 into the internal reaction volume space 109 of reactor 101, in the same manner as the heaters 150 are disposed within the internal reaction volume space 109, including piping 154″, high temperature sealed ultrahigh vacuum flange 155″, and passageway 156″
Still with reference to FIGS. 5 and 5-9, molten regolith electrolysis reactor 101 includes a regolith feed port 175, through which raw regolith 50 may be loaded into the internal reaction volume space 109 for processing. Regolith feed port 175 includes piping 176 fixedly secured to the lid 111 as by welding, and a high temperature sealed ultrahigh vacuum flange 177, with piping 176 communicating with the internal reaction volume space 109 via a passageway 178 extending from flange 177 to internal reaction volume space 109 through the layer of 108′ of thermal insulation in the lid 111. Suitable piping (not shown), a hopper (not shown) and valving (not shown) may be connected to flange 177, whereby regolith 50 may be obtained from the lunar surface 51, as by use of a robotic scoop carried by a lunar rover vehicle and fed into molten regolith electrolysis reactor 101 through flange 177 in such way that the internal gas composition of reactor 101 is not vented to the lunar environment upon loading regolith 50 through flange 177. Lid 111 may also be provided with oxygen exit port 180 of the same construction and disposition as regolith feed port 175, to permit any oxygen gas created in the internal reactor volume space to be outwardly extracted from reactor 101. Another port 185 may be provided through lid 111 of similar construction and disposition as feed port 175 and oxygen exit port 180, which port 185 could be used for other desired purposes including serving as a view port. The piping 102, 103 previously described in connection with FIGS. 1-4, which exits from the molten regolith electrolysis reactor 101 to be in fluid communication with piping 202 of the silicon refiner reactor 201 and piping 302 of the aluminum refiner reactor 301 are shown as closed tubes each also provided with high temperature sealed ultrahigh vacuum flanges 177′ like the previously described flange 177, and may contain valves to permit the pressure tight connection of piping 102, 103 to piping 202, 302. The fluid connections can also be piping segments open to the vacuum environment of space and connected to reactors 201 and 301.
With reference to FIGS. 3, and 10-12, the silicon refiner reactor 201 of system 100 is shown to include a housing 205 having an inner wall surface 206, and an outer wall surface 207. The inner wall surface includes a layer 208 of thermal insulation material, which preferably is a castable ceramic refractory material having the requisite strength and thermal conductivity characteristics to serve as a high temperature thermal insulator for use in a molten regolith or metal oxide electrolysis reactor. As shown in FIG. 12, the layer 208 of thermal insulation material on the inner wall surface 206 of housing 205 defines, or forms, an internal reaction volume space 209 within housing 205, wherein an electrolysis reaction may occur, as will be hereinafter described in greater detail. Preferably the internal reaction volume space 209 has a generally cylindrical configuration.
As shown in FIGS. 3 and 10-12, and in particular FIGS. 11 and 12, housing 205 preferably has a generally cylindrical configuration and preferably has a housing lower portion 210 and a lid 211 which mates with the lower portion 210. Preferably, housing 205 and lid 211 are made from stainless steel, or any other material that has the requisite strength and thermal characteristics to withstand the high temperature present in the silicon refiner reactor 201 during the electrolysis of the electrochemically extracted metal, or extracted metal, from the molten regolith electrolysis reactor 101, and to be exposed on the lunar surface 51 to the lunar vacuum environment. Lid 211 preferably also includes a layer 208′ of thermal insulation material which preferably is also a castable ceramic refractory material. Lid 211 of housing 205 includes piping 214 which includes a flange 215, and piping 214 is secured, as by welding, to the top of lid 211. Flange 215 is fixedly secured to piping 214 as by welding. A translation, or movement, generator 216, having a flange 217 at the top of the translation generator 216 and a flange 218 at the bottom of movement generator 216, is supported by translation generator support 224. Flange 218 is fixedly secured to flange 215 by a plurality of bolts 219 connecting flanges 215 and 218 together. Flanges 215, 217, and 218 are high temperature sealed ultrahigh vacuum flanges which provide a seal that can withstand the ultrahigh vacuum of the Moon, whereby in combination with other high temperature sealed ultrahigh vacuum flanges used in silicon refiner reactor 201, as will be hereinafter described, the interior of housing 205 and translation generator 216 are sealed off from the vacuum of space.
Silicon refiner reactor 201 includes at least one cathode 220 and at least one anode 230 to perform the electrolysis reaction within the internal reaction volume space 209. The at least one cathode 220 includes an electrical connector 221 attached to the upper end 222 of cathode 220, to transmit an electric current to the cathode 220, from a suitable electric power source, not shown. Suitable high temperature sealed ultrahigh vacuum seals provide a seal between the electrical connector 221 and flange 217 of movement generator 216 from the vacuum of space. The lid 211 and the lower portion 210 of housing 205 are provided with high temperature sealed ultrahigh vacuum flanges 240, 241, secured together with a plurality of bolts 242, or other suitable fasteners.
Still with reference to FIGS. 3 and 10-12, the at least one cathode 220 is disposed within the housing 205 and is moveable within the internal reaction volume space 209 as will be hereinafter described. Cathode 220 is disposed, or placed, within a compressible, flexible metal bellows 223. The at least one anode 230 is disposed, or placed, within housing 205, with at least a portion of the at least one anode 230 being disposed within the internal reaction volume space 209. The at least one anode 230 may include a plurality of anode rods 231 with the ends 232 of the anode rods 231 being disposed in the internal reaction volume space 209 in contact with extracted metal 240 contained within the internal reaction volume space 209, as will be hereinafter described. The bottom of the lower portion 210 of housing 205 includes piping 214′ which includes a flange 215′; and piping 214′ is secured to the bottom of the lower portion 210 of housing 205 as by welding. Flange 215′ is fixedly secured to piping 214′ as by welding. A flange 218′ is secured to flange 215′ by a plurality of bolts, and electrical connector 221′ passes through flanges 215′ and 218′ to provide electric current to cathode 230. Flanges 215′ and 218′ are high temperature sealed ultrahigh vacuum flanges as previously described.
Still with reference to FIGS. 3 and 10-12, flange 217 and flange 218 of the movement generator 216 are connected by the compressible, flexible metal bellows 223, which permits motion, or movement, of flange 217 and the electrical connector 221 attached to the upper end 222 of cathode 220. Three motor drivers, or motors, 225 associated with the translation, or movement, generator 224, move the translation generator 224 either up and down in a direction parallel to the longitudinal axis 230′ of anode 230, or in a direction perpendicular to the longitudinal axis 230′ of anode 230. The movement, or translation, of the translation generator 224, in turn can cause the upward or downward movement of cathode 220 within the internal reaction volume space 209 or can cause a side-to-side movement of the cathode 220 within the internal reaction volume space 209. The foregoing described movement of the cathode 220 may assist in mixing of the electrochemically extracted metal 240 from the molten regolith electrolysis reactor 101 within the internal reaction volume space 209. Alternatively, the cathode base plate 226 attached to the lower end 227 of cathode 220 and disposed perpendicular to the longitudinal axis 220′ of cathode 220 could be tilted, or disposed at an acute angle, with respect to the longitudinal axis 230′ of anode 230. Upward and downward movement of translation generator 224 and cathode 220 will then mix the electrochemically extracted metal, e.g., Fe—Si 240, from the molten regolith electrolysis reactor 101.
Still with reference to FIGS. 3 and 10-12, the silicon refiner reactor 201 includes at least one heating system which may be a heater 150 which is used to initially melt the extracted metal nominally Fe-Si 240 which has been loaded into reactor 201 via piping 202 from piping 102 of the molten regolith electrolysis reactor 101 and into the internal reaction volume space 209 (FIG. 12). Preferably a plurality of heaters 150 are disposed within the housing 205 with a portion of each heater 150 disposed in the internal reaction volume space 209. In the embodiment of the silicon refiner reactor 201 illustrated, eight heaters 150 are utilized and a portion of each heater 150, or the ends 151 of each heater 150 are disposed, or placed within, the internal reaction volume space 209. The heaters 150 preferably are spaced radially around the housing 205. Each heater 150 is powered by an electric current which may be passed through two copper power feed rods 152, or other suitable electrical connectors, into a wire coil heater element 153 to create and supply heat energy to the extracted metal 240 in the internal reaction volume space 209. Each heater 150 is disposed in housing 205 through a piping 154 fixedly secured to the outer wall surface 207 of housing 205 as by welding, which piping 154 is sealed by a high temperature sealed ultrahigh vacuum flange 155, which includes suitable seals for the power connectors 152 which pass through flange 155; and then via a passageway 156 formed in the thermal insulation layer 208 extending from the inner surface wall surface 206 of housing 205 into the internal reaction volume space 209.
At least one temperature sensor 160 such as a thermocouple, may be provided to permit the temperature of the molten extracted metal 240 within the internal reaction volume space 209 to be measured and monitored. As shown in FIGS. 3 and 10-12, two or more temperature sensors 160 may be utilized, each temperature sensor 160 passing through the lid 211 or other portion of reactor 201 into the internal reaction volume space 209 in the same manner as the heaters 150 are disposed within the internal reaction volume space 209, including piping 254, high temperature sealed ultrahigh vacuum flange 255, and passageway 256. At least one liquid level sensor 170 may be provided to measure and monitor the level of extracted iron in the internal reaction volume space 209. One liquid level sensor 170 is shown passing through the outer wall surface 207 of housing 205 into the internal reaction volume space 209 of reactor 201, in the same manner as the heaters 150 are disposed within the internal reaction volume space 209, including piping 254, high temperature sealed ultrahigh vacuum flange 255, and passageway 256. An electrolyte feed port 250 is provided to lid 211 to permit an electrolyte, such as a fluoride electrolyte permeable to silicon ions, to be fed into the internal reaction volume space 209 via a passageway 251 extending through the layer 208′ of insulation of lid 211. Feed port 250 includes a high temperature sealed ultrahigh vacuum flange 256 secured to piping 257.
With reference to FIGS. 3, and 13-15, the aluminum refiner reactor 301 of system 100 is shown to include a housing 305 having an inner wall surface 306, and an outer wall surface 307. The inner wall surface includes a layer 308 of thermal insulation material, which preferably is a castable ceramic refractory material having the requisite strength and thermal conductivity characteristics to serve as a high temperature thermal insulator for use in a molten regolith, or molten metal oxide, electrolysis reactor. As shown in FIG. 15, the layer 308 of thermal insulation material on the inner wall surface 306 of housing 305 defines, or forms, an internal reaction volume space 309 within housing 305, wherein an electrolysis reaction may occur, as will be hereinafter described in greater detail. Preferably the internal reaction volume space 309 has a generally cylindrical outer configuration, which is divided by an electrically insulating refractory ceramic separation wall 310 into a generally U-shaped configuration with a reaction space 309L and a reaction space 309R as seen in FIG. 15. Reaction spaces 309L, 309R may be hermetically isolated to hold an anode and cathode, respectively.
As will be hereinafter described in greater detail, the electrolysis reaction occurring in internal reaction volume spaces 309L and 309R separates the molten metal oxide slag 340 into substantially pure aluminum, a substantially pure magnesium vapor, a liquid metal oxide slag, and high temperature oxygen gas. The aluminum and magnesium are collected at the cathode 320 on the right side of the separation wall 310, or in reaction space 309R as they have lower density that the molten slag; and the oxygen gas collects on the left side of the separation wall 310, or in reaction space 309L. The separation wall 310 prevents a reoxidation reaction between the metal atoms and the high temperature oxygen gas. The U-shaped internal reaction volume 309, including reaction spaces 309L and 309R, is preferred as the separated products have a lower density than the original molten metal oxide slag 340 and the products will float upwards, or toward lid 311 in a gravitational field, such as in the low gravitational field of the Moon and be extracted for use.
This reactor design and mode of operation can also be applied in an Earth environment where a stronger gravitational field will more rapidly drive the density separation. At least one anode may be disposed within housing 305, at least a portion of which may be, for example, disposed in reaction spaces 309L and/or 309R. At least one anode may be moveable within an internal reaction volume space 309L and/or 309R, in some examples. Likewise, at least one cathode may be disposed within housing 305, at least a portion of which may be, for example, disposed in in reaction spaces 309L and/or 309R. At least one cathode may be moveable within an internal reaction volume space 309L and/or 309R, in some examples.
As shown in FIGS. 3 and 13-15, and in particular FIGS. 14 and 15, housing 305 preferably has a generally cylindrical configuration and preferably has a housing lower portion 310 and a lid 311 which mates with the lower portion 310. Preferably, housing 305 and lid 311 are made from stainless steel, or any other material that has the requisite strength and thermal characteristics to withstand the high temperature present in the aluminum refiner reactor 301 during the electrolysis of the liquid metal oxide slag received from the molten regolith electrolysis reactor 101, and to be exposed on the lunar surface 51 in the vacuum environment of the Moon. Lid 311 preferably also includes a layer 308′ of thermal insulation material which preferably is also a castable ceramic refractory material. Lid 311 of housing 305 includes two lengths of piping 314 which each include a flange 315, and piping 314 is secured, as by welding, to the top of lid 311. Flanges 315 are fixedly secured to piping 314, e.g., by welding. Two translation, or movement, generators 316, each having a flange 317 at the top of each translation generator 316 and a flange 318 at the bottom of each translation generator 316, are each supported by a translation generator support 324. Flanges 318 are fixedly secured to flanges 315 by a plurality of bolts 319 connecting flanges 315 and 318 together. Flanges 315 and 318 are high temperature sealed ultrahigh vacuum flanges which provide a seal that can withstand the ultrahigh vacuum environment of the Moon, whereby in combination with other high temperature sealed ultrahigh vacuum flanges used in aluminum refiner reactor 301, as will be hereinafter described, the interior of housing 305 and translation generators 316 are sealed off from the vacuum of the Moon.
Aluminum refiner reactor 301 includes at least one cathode 320 and at least one anode 330 to perform the electrolysis reaction within the internal reaction volume spaces 309L, 309R. Cathode 320 and anode 330 each include an electrical connector 321, to transmit an electric current between the anode 330 and cathode 320, from a suitable electric power source, not shown. Suitable high temperature sealed ultrahigh vacuum seals provide seals between the electrical connector 321 and flange 317 of translation generators 316 from the vacuum of space. As seen in FIGS. 3 and 13-15, two sets of cathodes 320 and anodes 330 are preferably utilized. The lid 311 and the lower portion 310 of housing 305 are provided with high temperature sealed ultrahigh vacuum flanges 340, 341, secured together with a plurality of bolts 342, or other suitable fasteners.
Still with reference to FIGS. 3 and 13-15, the at least one cathode 320 and the at least one anode 330 are each disposed within housing 305 and are moveable within the internal reaction volume spaces 309L, 309R as will be hereinafter described. Cathode 320 and anode 330 are each disposed within a compressible, flexible metal bellows 323, and each cathode 320 and anode 330 are disposed in the internal reaction volume space 309 in contact with the molten metal oxide slag 340 in the internal reaction volume space 309. Anode 330 and cathode 320 are of the same construction and are each generally a cylindrical member 331.
At least one temperature sensor 160 such as a thermocouple, may be provided to permit the temperature of the molten extracted metal 340 within the internal reaction volume space 309 to be measured and monitored. As shown in FIGS. 3 and 13-15, two or more temperature sensors 160 may be utilized, each temperature sensor 160 passing through the lid 311 or other portion of reactor 301 into the internal reaction volume spaces 309L and 309R in the same manner as the heaters 150 are disposed within the internal reaction volume space 309, including piping 154′, high temperature sealed ultrahigh vacuum flange 255, and passageway 256. At least one liquid level sensor 170 may be provided to measure and monitor the level of the molten extracted metal 340 in the internal reaction volume space 309. One liquid level sensor 170 is shown passing through the outer wall surface 307 of housing 305 into the internal reaction volume space 309 of reactor 301, in the same manner as the heaters 150 are disposed within the internal reaction volume space 309, including piping 254, high temperature sealed ultrahigh vacuum flange 255, and passageway 256.
Still with reference to FIGS. 3 and 13-15, aluminum refiner reactor 301 preferably includes 2 gas exit ports 370, 375 in the lid 311, in fluid communication with the internal volume reaction spaces 309L, 309R. Exit port 370 permits oxygen gas to be removed from the internal volume reaction space 309L in which the anode 330 is disposed; and gas exit port 375 permits magnesium vapor to be removed from the internal volume reaction space 309R. Gas exit ports 370, 375 are of similar construction as oxygen exit port 180 and regolith feed port 175 of FIG. 6, and each gas exit port 370, 375 includes pipings 371, 376, fixedly secured to lid 311 as by welding, with a high temperature sealed ultrahigh vacuum flange 377, 378 secured to the pipings 371, 376. Two cold traps 380, 385, are in fluid communication with the gas exit ports 370, 375 to cool oxygen gas and to cool and capture the magnesium vapor for subsequent processing.
As to the electrolysis reactions of the molten regolith electrolysis reactor 101, depending on regolith composition, the raw regolith 50 melts between 1100-1450° C. The molten regolith electrolysis reactor operating temperature is higher—around 1650° C.—so that the molten metal oxide resistivity is low enough to support electrolysis. The heaters 150 perform the initial melting of the raw regolith 50, and once a molten state at the required operating temperature has been reached, the heaters 150 are turned off to allow the oxide electrolysis reactions to provide sufficient internal Joule heating due to the electrical resistivity of the regolith melt 150′, to maintain the desired operating temperature. A controlled voltage is applied to the anode 120 and cathode 130 which forces a large amount of current to run between the anode 120 and cathode 130 and through the regolith melt 50′. This current causes the metal oxides in the regolith 50 to be reduced into oxygen atoms and respective pure metal atoms at voltages that are determined by the order of increasing oxide stability. The anode 120 is best to be a conducting material, and chemically and high temperature inert. It can also be a high temperature conducting material that is coated with a nearly inert but expensive material such as iridium coating survives in the high temperature oxygen environment. The molten regolith electrolysis reactor 101 principal initial electrolysis reactions are:
2FeO□2Fe+O2
SiO2□Si+O2
Under the reduction of the iron and silicon oxides, the iron and silicon chemically combine to form FeSi. These electrolysis reactions produce the three initial products which then feed into the silicon refiner reactor 201 and aluminum refiner reactor 301: the electrochemically extracted FeSi molten metal 240; liquid metal oxide slag 340 composed of the metal oxides present in the regolith 50 with high oxide stabilities; and high temperature O2 gas. The liquid metal oxide slag's composition is nominally Al2O3—CaO—MgO—TiO2 along with additional low concentration lunar oxides present in the regolith.
The liquid FeSi product 240 from the molten regolith electrolysis reactor 101 feeds into the silicon reactor 201, which utilizes a fluoride electrolyte permeable to silicon ions to facilitate this secondary refining electrolysis reaction. The design of the silicon refiner reactor 201 has an operating temperature around 1600° C. for the high temperature electrolyte and ferro-silicon melt 240. During electrolysis operation, the fluoride electrolyte serves as a transport medium through which the Si ions travel to the cathode 220. Once the FeSi 240 and the heaters 150 melt the electrolyte and the FeSi, an electric potential is applied to the cathode 220 and anode 230 and the electric current forces the Si to dissociate from the Fe and diffuses upward through the electrolyte to the cathode 220 due to lower density. The silicon depleted liquid Fe is captured at the bottom anode 230 while the substantially pure liquid silicon product is captured at the top cathode 220. The purity of the liquid silicon product may approach up to 99.99% pure. The silicon refiner reactor 201 is equipped with a liquid silicon tap 203 (FIGS. 10-12) and a liquid Fe alloy tap 204 (FIGS. 10-12). The silicon can then be cast into ingots, eventually used for solar cell production or other semiconductor applications, and the liquid Fe can be cast into ingots, structural molds, or additive manufacturing wire. Tapping for these products occurs at periodic timed intervals. The silicon refiner reactor electrolysis reaction is: FeSi□Fe+Si.
The liquid metal oxide slag 340 from the molten regolith electrolysis reactor 101, via tap 103 (FIG. 5), can be fed into the aluminum refiner reactor 301 via flange 302 (FIGS. 14 and 15), where a secondary electrolysis process separates Al2O3—CaO—MgO—TiO2 into liquid 99% pure Al, 99% pure Mg vapor with trace amounts of Al vapor, a principally CaO—TiO oxide slag, and high temperature O2 gas. This reactor 301 utilizes the U-shaped internal reaction volume spaces 309L, 309R and the positively charged Al and Mg ions collect at the cathode 320 on the right side of the electrically insulating refractory ceramic separation wall 310, while the negatively charged O2 gas collects at the anode 330 on the left side of the ceramic separation wall 310. This separation wall 310 prevents a reoxidation reaction between the metal products by the high temperature oxygen product.
The aluminum refiner reactor 301 may operate at a temperature near or above 1600° C. The aluminum refiner reactor 301 is equipped with a liquid Al tap 150 (FIG. 15), a liquid ceramic slag tap 303 and two gas outlets 375, 370 for the Al and Mg vapor product and the O2 gas, respectively. The substantially pure aluminum liquid product can then be directly cast into ingots, trusses, plates, etc., or additive manufacturing wire. The purity of the liquid aluminum product may approach 99% pure. The 99% pure Mg vapor is captured in the cold trap 385, and then heated to its melting point to be cast as liquid Mg into ingots, trusses, plates, etc., or additive manufacturing wire. The liquid ceramic slag principally composed of CaO+TiO and other regolith present low concentration oxides can also be directly cast into refractory ceramic bricks or further refined to extract Ca, Ti, and other trance metals. The O2 gas outlet 370 feeds into cold trap 380. The aluminum refiner reactor 301 principal electrolysis reactions are:
2Al2O3□4Al+3O2
2MgO□2Mg+O2
While several exemplary embodiments have been provided in the present disclosure, it may be understood that the disclosed embodiments might be embodied in many other specific forms without departing from the spirit or scope of the present disclosure and the appended claims. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted, or not implemented.
In addition, the various exemplary embodiments described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as coupled or directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and may be made without departing from the spirit and scope disclosed herein.
At least one embodiment is disclosed and variations, combinations, and/or, modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. When numerical ranges or limitations are expressly stated, such express ranges or limitations may be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4,etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). The use of the term “about” means+10% of the subsequent number, unless otherwise stated.
Use of broader terms such as comprises, includes, and having may be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above, but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present disclosure.
Patent Application
20250084553
