Apparatus and process for continously producing a metal

Abstract

A metal recovery apparatus for recovering a selected metal from a metal bearing feed material, the apparatus comprising: a feeding unit configured to feed the metal bearing feed material onto at least one movable receptacle; a metal extraction unit which is connected to the feeding unit, the metal extraction unit including an internal space which is heated and in which the selected metal is separated from the metal bearing feed material as a metal vapour; at least one condenser which is fluidly connected to the internal space of the metal extraction unit to condense the metal vapour from the internal space to form a metal product; and a drive unit for driving movement of the at least one movable receptacle though the feeding unit and the metal extraction unit, wherein the feeding unit, the metal extraction unit, the at least one condenser, and the movable receptacles therein are enclosed within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers.

Description

[0001] APPARATUS AND PROCESS FOR PRODUCING A METAL PRIORITY CROSS-REFERENCE

[0001] The present application claim priority to Australian Provisional Patent Application No.2024900807 filed on 26 March 2024, the contents of which should be understood to be incorporated therein by this reference. TECHNICAL FIELD

[0002] A new apparatus and process for continuously recovering a metal from a metal bearing feed material is disclosed. This apparatus and process may be particularly applicable for recovering a metal such as magnesium using a distillation or thermal reduction process within a vacuum retort type arrangement, and will be described within this context. However, it should be appreciated that the system and process may be applied to any metal that could be similarly produced using thermal reduction, thermal recovery, metal distillation or equivalent metal separation process. BACKGROUND

[0003] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[0004] Magnesium is typically produced using a thermal reduction route, known as the Pidgeon Process, where a magnesium raw material such as dolomite is calcined to produce magnesium oxide, which is then heated at a high temperature with a reducing agent, such as ferrosilicon, under vacuum to thermally reduce the magnesium oxide to magnesium. In these conditions (temperature at least 1200 ºC and high vacuum – pressure below 100 Pa) a magnesium vapour is produced, which may be subsequently cooled and condensed to form solid magnesium metal. The overall reaction is endothermic, and thus may have a high energy requirement. To keep reaction temperatures low, the processes are typically operated under a high vacuum.

[0005] In many cases, the high and high temperature conditions required for the thermal reduction of magnesium necessitates the use of a batch type process, in order to create those conditions in a sealed environment. However, batch production can limit the productivity of the process, as operation of the production apparatus includes ancillary steps including startup, shutdown, loading and unloading processes. In addition, thermal losses occur during these ancillary steps.

[0006] Similarly, the purification of metals such as magnesium, for example using a metal distillation process, also requires low pressure and high temperature conditions which typically necessitates the use of a batch type process, in order to create those conditions in a sealed environment. Again, this can limit the productivity of the process.

[0007] There would therefore be some advantage in providing an apparatus and related continuous process for recovering a metal, such as magnesium, from a metal bearing feed material that may be configured for a thermal reduction process, a metal distillation process or the like. SUMMARY

[0008] A metal recovery apparatus and / or process is disclosed that maybe used to recover a metal from a metal bearing feed material. The process may be utilised for thermal reduction and separation of a desired metal from a metal bearing feed material; or for temperature based separation, such as metal distillation, of a desired metal from a metal bearing feed material.

[0009] A first embodiment provides a metal recovery apparatus for recovering a selected metal from a metal bearing feed material, the apparatus comprising: a feeding unit configured to feed the metal bearing feed material onto at least one movable receptacle; a metal extraction unit which is connected to the feeding unit, the metal extraction unit including an internal space which is heated and in which the selected metal is separated from the metal bearing feed material as a metal vapour; at least one condenser which fluidly connected to the internal space of the metal extraction unit to condense metal vapour from the internal space to form a metal product; and a drive unit for driving movement of the at least one movable receptacle though the feeding unit and the metal extraction unit, wherein the feeding unit, the metal extraction unit, the at least one condenser, and the movable receptacles therein are enclosed within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers.

[0010] This first embodiment therefore provides a metal recovery apparatus capable of continuously producing a metal from a metal bearing feed material. Feed material may be continuously moved through the metal extraction unit on at least one moveable receptacle (typically on a series of moveable receptacles) by the drive unit, to be separated from the metal bearing feed material as a metal vapour therein to produce the desired metal through thermal reduction. This enables continuous production of the metal, through continuous throughput of the feed material through the system. Additionally, the feeding unit, metal extraction unit and the at least one condenser are advantageously contained within an atmosphere controlled chamber that provides environment control therein.

[0011] The metal extraction unit may be configured to heat the metal bearing feed material to produce a metal vapour therein. That metal vapour may be produced by boiling point differentiation of the selected metal and other components of the metal bearing feed material, or may be produced as a result of a reaction, for example a reduction reaction - such as a thermal reduction reaction. The metal recovery apparatus may therefore comprise one or more of: a thermal separation apparatus, a distillation apparatus / metal distillation apparatus, a reduction apparatus, a thermal reduction apparatus, or the like.

[0012] In some forms, this first embodiment may comprise a thermal reduction apparatus capable of continuously producing a metal such as magnesium from a metal bearing feed material (for example a magnesium oxide containing feed material). In these forms, the metal extraction unit may be configured for a thermal reduction reaction of the bearing feed material that produces a metal vapour. Alternatively, this embodiment may comprise a distillation apparatus capable of continuously separating a metal such as magnesium, lithium or the like from a metal bearing feed material based on the differential boiling points of the components of the metal bearing feed material. In these forms, the metal extraction unit may be configured for the selected metal to be separated from the metal bearing feed material based on boiling point of said selected metal to produce the metal vapour.

[0013] Continuous production may be further facilitated by returning each movable receptacle back to the feeding unit once that movable receptacle has passed through the metal extraction unit. In embodiments, the at least one movable receptacle may be configured to be returned to the feeding unit to receive further metal bearing feed material after the at least one movable receptacle exits the metal extraction unit. This return may be facilitated by any suitable means, for example a further drive unit of receptacle return unit may be used to receive and transport each moveable receptacle from the exit of the metal extraction unit back to the feeding unit. However, the apparatus may be configured so that the drive unit drives movement of the at least one movable receptacle to be returned to the feeding unit. This may advantageously utilise the drive unit for movement around the various stages / units of the apparatus.

[0014] The system may be fully enclosed under low pressure conditions (typically deep vacuum conditions), so that the feed material and receptacles are enclosed within a controlled environment. In this regard, the atmosphere controlled environment may be used to ensure that the temperature and environment remains constant throughout the apparatus. It should be understood that “low pressure” and “low pressure conditions” refers to the pressure being less than atmospheric pressure (i.e. less than ~100 Pa absolute (equivalent to 0.001 bar)). In embodiments, the feeding unit, the first condenser, the second condenser, and the movable receptacles therein may be enclosed within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers. In some embodiments, the drive unit may also be enclosed within that atmosphere controlled chamber fluidly linked atmosphere controlled chambers. The atmosphere controlled chamber or linked atmosphere controlled chambers may have an atmosphere therein by an atmosphere control unit configured to maintain the desired atmospheric conditions therein. Enclosing the key units within a controlled atmosphere facilitates good process control of the thermal reduction process, and controls the influx of impurities that may otherwise enter the apparatus / system. For example, the controlled environment may allow any dust that is present to settle quickly as there is little or no atmosphere to suspend the fine particles. It is noted that dust is an impurity that may find its way into the metal recovered on the condenser or condensers. This low pressure may be created by a strong vacuum pump, which may be used to reduce the pressure to less than 100 Pa. The atmosphere controlled chamber or fluidly linked atmosphere controlled chambers may include at least one vacuum pump capable of producing a pressure of less than 50 Pa, preferably from 5 to 50 Pa absolute, more preferably from 10 to 40 Pa absolute, yet more preferably from 10 to 25 Pa absolute. In many cases, the metal extraction process may be optimised by keeping pressure within the metal extraction unit below 40 Pa.

[0015] The atmosphere controlled chamber may have any suitable configuration. The atmosphere controlled chamber may comprise a common or shared atmosphere controlled chamber, or alternatively may comprise multiple chambers that are fluidly linked. In embodiments, the atmosphere controlled chamber may comprise at least one vacuum chamber which is divided into at least the feeding unit and the metal extraction unit using at least one divider or baffle. The at least one vacuum chamber may be configured with at least one sealable pressure door through which the interior may be accessed. The at least one vacuum chamber may include one or more peripheral ports through which the at least one condenser may be located and extend from, and a movable receptacle recycling unit (for example a chute as described below) may be connected.

[0016] The low pressure atmosphere within the system may necessitate minimising, more typically substantially preventing, air ingress into the metal extraction unit. The system may therefore be substantially fluid tight, and include a variety of seals, valve seals or the like.

[0017] Recovery of the selected the metal bearing feed material may be undertaken within the metal extraction unit in a single stage, or in two or more stages. In a single stage process, the feed material may be heated in a single internal space, which is fluidly connected to a single condenser unit. Where two or more stages are used, the internal space of the metal extraction unit may be sequentially divided into at least two heated spaces in a movement direction of the feed material through the metal extraction unit, with each heated space being connected to a separate condenser. For example, the at least two heated spaces may comprise at least a first heated space, and a second heated space. The apparatus may then include two or more condensers, with each condenser connected to a separate heated spaced. For example, a first condenser may be fluidly connected to the first heated space of the metal extraction unit to condense a first metal vapour from the first heated space; and a second condenser may be fluidly connected to the second heated space of the metal extraction unit to condense a second metal vapour from the second heated space. This can allow the feed material to be sequentially heated to different temperatures whilst moving through the metal extraction unit (i.e. through the first heated space and then the second heated space), enabling different species to vaporise depending on the boiling point / vapour point of that species.

[0018] It should be appreciated that the internal space may be divided into further heated spaces, with each heated space being connected with a separate condenser. For example, where the internal space is sequentially divided into at least three spaces in a movement direction of the feed material through the metal extraction unit, said three spaces may each be connected to a separate condenser.

[0019] For example, the first heated space may be configured to heat the feed material to a temperature in which a first component or species such as impurities from the feed material are substantially vapourised, and the second heated space may be configured to heat the feed material to a temperature in which the selected metal in the feed material is substantially vapourised. These temperature ranges may vary, depending on the metal that is being recovered. For example, for the thermal of a magnesium oxide rich feed material, the first heated space may be to enclose and heat the metal bearing feed material therein to between 200 to 1150 °C, preferably between 700 and 1150°C, more preferably between 800 and 1100 °C. Similarly, the second heated space may be configured to enclose and heat the metal bearing feed material therein to between 1100 and 1300 °C, preferably greater than 1150°C, more preferably at least 1200 °C. This differential temperature may be achieved using two different heating zones, with two different set point temperatures. However, even where a single heating source (for example a furnace) is used, it should be appreciated that the metal bearing feed material that enters the heated zone of the metal extraction unit will be progressively heated from feed temperature (typically less than 100 °C) to at least 1200 °C, and that progressive heating profile can be utilised to differentiate the different heating zones therein. Movement of the metal bearing feed material through the internal space of the metal extraction unit and heated zone therein may progressively move that metal bearing feed material through the first heated space through to the second heated space, as well as progressively heat the metal bearing feed material to at least 1200 °C. The size of the first heated space may therefore be configured to include metal bearing feed material that is between for example 200 to 1150 °C during that heating up process. The use of the two strategically positioned condensers in this type of configuration may allow a high purity metal, for example Mg, to be produced that does not need refining. One example of high purity metal is greater than 99 % purity, more particularly greater than 99.5% purity, and more particularly greater than 99.7% purity. This may be collected from the second condenser, whilst impurities from the feed material may be extracted and collected from the first condenser, prior to the feed material passing into the second internal space.

[0020] The internal space of the metal extraction unit may be sequentially divided into at least two heated spaces in a movement direction of the feed material through the metal extraction unit by at least one baffle. The internal space may include at least two baffles positioned at or proximate the ends of the internal space. These baffles may function to retain the internal gas / vapour flow within that internal space. Where the internal space is divided into at least two different heated spaces, for example a first second heated spaces, those heated spaces may be separated by any of baffles. Where a first and a second heat space are provided, the at least one baffle may comprise a first baffle, a second baffle and a third baffle, the first and third baffles being positioned at or proximate the ends of the internal space, and the second baffle being positioned between the first and third baffles to divide the internal space into the first heated space and the second heated space. The first baffle, second baffle and third baffle may be spaced apart along the direction of movement of the feed material. The first and third baffles may be positioned at or proximate the ends of the internal space (i.e. the start and finish of the internal space in the movement direction of the feed material). Each baffle may comprise a sheet, plate or membrane. The baffles may be configured to direct vapour produced from heating the feed product within the adjoining internal space towards the respective fluidly connected condenser. Additionally, each baffle may include guide sections configured to space the baffles away from the at least one movable receptacle. The guides ensure that the baffles avoid snagging the receptacles as they move through the metal extraction unit.

[0021] As noted above, the first heated space may be configured to heat the feed material to a temperature in which a first component or species such as impurities from the feed material are substantially vapourised, and the second heated space may be configured to heat the feed material to a temperature in which the selected metal in the feed material is substantially vapourised. In this configuration, the second baffle’s function may be to funnel that first component or species – for example impurities from the feed material – e.g. Na, K, Cl, H2O and CO2 when producing Mg from an MgO rich feed material - towards the first condenser, enabling the second condenser to harvest higher purity metal (for example Mg metal). This higher purity metal may not require refining if it is collected at a sufficient purity (i.e. substantially free of impurities collected in the first condenser). One example of high purity metal is greater than 99 % purity, more particularly greater than 99.5% purity, and more particularly greater than 99.7% purity. The metal collected on the first condenser will be of a smaller amount as the first heating space is designed so that the feed material moving through the metal extraction unit may have only just hit the temperature where metal vapour is formed before it through the second baffle. The impurities are liberated at a lower temperature the metal vapour. The metal from first condenser may require refining depending on the impurity content. As noted below, the condensers are controlled to ~400 °C. At this temperature, the impurities will likely not settle on the heated surface, but instead the impurities will more likely travel through to an impurity collection unit, for example water cooled waste pot.

[0022] The metal extraction unit may be configured in a vacuum retort type arrangement, where the metal bearing feed material is vapourised and flows through a cooler vapour collection conduit or pipe where it is condensed into a solid metal on a condenser situated therein or in fluid communication therewith. In these embodiments, the metal extraction unit includes at least one vapour collection conduit which fluidly connects the internal space to the respective condenser. Each of the condensers may be positioned within or fluidly connected to the vapour collection conduits. Where the internal space is divided into two or more heated spaces, each heated space may have a vapour collection conduit that is in fluid communication with the respective fluidly connected condenser. For example, where there are two heated spaces, each of the first heated space and the second heated space have a vapour collection conduit that is in fluid communication with the respective fluidly connected condenser. Each vapour collection conduit may have any suitable configuration. For example, each vapour collection conduit may comprise a pipe.

[0023] The respective vapour collection conduits may be positioned to selectively collect different vapour compositions that are produced within the metal extraction unit. In embodiments, the first heated space may be connected to first condenser using a first vapour collection conduit which is positioned to collects vapours from receptacles moving through the metal extraction unit where the feed material is heated to between 200 to 1150 °C, preferably between 700 and 1150°C, more preferably between 800 and 1100 °C. Similarly, the second heated space may be connected to second condenser using a second vapour collection conduit which is positioned to collect vapours from receptacles moving through the metal extraction unit where the material is heated to between 1100 and 1300 °C, preferably greater than more preferably at least 1200 °C.

[0024] The metal extraction unit may include or may be located within a heated enclosure. The heated enclosure may comprise any suitable high temperature enclosure, for example a furnace or similar vessel. That heated enclosure may in some embodiments be configured to produce at least two different heating zones within the internal space of the metal extraction unit. Those different heating zones may have different temperatures, as discussed above for the first heated space and second heated space. These different heated zones (and thus temperature zones) can allow for differentiated extraction of parts of the metal bearing feed material. For example, one heated zone can be used to preferentially remove impurities, whilst a second heated zone can be used to extract the selected metal as a metal vapour, thus producing a metal vapour of high purity that can be recovered on the respective condenser at a high purity. One example of high purity metal is greater than 99 % purity, more particularly greater than 99.5% purity, and more particularly greater than 99.7% purity. As noted above, the heated zone may be produced by utilising the progressive heating of the feed material from feed temperature (typically less than 100 °C) to the temperature within the heated zone, with that progressive heating profile being used to differentiate the different heating zones therein. Movement of the metal bearing feed material through the internal space of the metal extraction unit and heated zone therein may progressively move that metal bearing feed material through the first heated space through to the second heated space, as well as progressively heat the metal bearing feed material. Alternatively, each of the heated zones, for example the first heated space and the second heated space, may have different or separate heat sources that can be controlled to produce a different temperature within the different heated zones.

[0025] The vapour collection conduits may be cooler than the internal space within the metal extraction unit to facilitate cooling of the vapour prior to condensation. In some embodiments, the vapour collection conduits may extend outside of the heated zone of the metal extraction unit, and include at least one heating unit to heat the content therein. For example, the content of the vapour collection conduits may be kept °C by use of a further heating source, such as electric / ceramic pipe

[0026] The metal bearing feeding material may comprise any suitable feed material that can be deposited onto the movable receptacle. For example, the metal bearing feed material may comprise a particulate feed material, or a briquette. In embodiments, the particulate feed material may comprise any suitable particulate material such as a powder, pellet, grain, bead, pill or the like. The particulate feed material may therefore comprise a powder feed material or a pellet feed material at 25 ºC. The particulate feed material may comprise a mixed powder at 25 ºC (i.e. at or around ambient temperature) in some embodiments.

[0027] The selected metal that is recovered from the metal bearing feed material can comprise a variety of target metals. Examples of the selected metal includes at least one of lithium, calcium, magnesium, titanium, silicon, or a rare earth metal

[0028] In some embodiments, the metal bearing feed material may comprise a metal that includes impurities that needs to be refined to increase the purity of the metal. For example, the metal bearing feed material may comprise magnesium having purity of less than 95 wt%, which is desired to be refined to a purity of greater than 99 wt%, for example greater than 99.5% purity, and more particularly greater than 99.7% purity. Other metals that may benefit from distilling to purify may include titanium, calcium and silicon.

[0029] In some embodiments, the metal bearing feed material may comprise a metallic precursor material that may be thermally reduced to form the desired metal. That metallic precursor may comprise any suitable metallic salt or compound. For example, the metallic precursor may comprise a metal oxide. One example may be magnesium production in which the metallic precursor may comprise magnesium oxide.

[0030] The first embodiment may provide a thermal reduction apparatus for producing magnesium in certain forms or embodiments. Here, the feed material may comprise a magnesium oxide rich mixture that is mixed with a reductant and the metal product substantially magnesium. Any suitable reductant may be used, for example the may comprise aluminium, carbon, or at least one silicon, for example ferrosilicon. In some examples, calcium fluoride can be added as a catalyst for the reduction. Similarly, the composition of the MgO rich mixture may comprise any suitable MgO containing mixture, and that composition typically depends on the source material from which the MgO is produced. In some embodiments, the MgO mixture may be formed from calcined dolomite. Dolomite typically comprises 60% calcium carbonate and 40% magnesium carbonate with trace impurities Na, K, Cl. These trace impurities remain in the MgO rich mixture and are preferably removed in the process in order to collect a pure Mg metal product. In other embodiments, the MgO rich mixture may result from other sources (mined magnesite (MgCO3), or magnesium chloride hydrolysed to hydroxide) may also include these and other impurities that are preferably removed in the Mg production process. Where magnesium is produced, the residue formed once the magnesium metal is separated from the metal bearing feed material may have a Portland cement type composition. In this regard, the chemistry of the MgO rich mixture, particularly when sourced from dolomite, may be augmented with a calcium containing material, for example lime (CaO), to produce a Portland cement composed residue. The residue (typically comprising around 80% of the mass of the metal bearing feed material) can therefore provide a secondary commercial product created from that feed material.

[0031] The feeding unit may comprise any suitable particulate feeding arrangement that may dispense the metal bearing feed material. In those embodiments where the metal bearing feed material comprises a particulate material such as powder or pellets, the feeding unit may include a feed hopper configured to feed the metal bearing feed material onto the at least one movable receptacle. The feed hopper preferably has a low pressure atmosphere maintained by the atmosphere control unit. The feed hopper may therefore also be part of or within the atmosphere-controlled chamber. The flow of metal bearing feed material dispensed from the feed hopper may be controlled using a variety of powder feeding arrangements. For example, a variety of valves, slot feeding arrangements, or the like could be used. In some embodiments, the feed hopper includes a screw feeder for flow the feed material onto the at least one movable receptacle. The screw may be driven by a variable speed motor to control the flow / feed speed. Once the metal bearing feed material is dispensed into the receptacles, that material may be optionally spread evenly for uniform thickness using a rake, plate comb or the like.

[0032] The movable receptacle(s) may have any suitable form that facilitates movement of the metal bearing feed material through the metal extraction unit. The at least one movable receptacle may comprise at least one recessed body, for example a container, and preferably a short walled container such as a tray. The container may include a walled cavity configured to hold the metal bearing feed material therein. For continuous metal production, a plurality of movable receptacles is typically desired, onto which metal bearing feed material may be continuously fed, and then moved into and through the metal extraction unit. Here, the at least one movable receptacle may comprise at least one of: a series of individual trays, a connected chain of trays, a continuous chain or belt including recesses, for example tray recesses, or an auger or screw feeder, that are driven by the drive unit. This series of trays, or chain / belt of recesses may cycle through the metal extraction unit, and be returned to the feeding unit to be refilled with metal bearing feed material.

[0033] The at least one movable receptacle may be formed from any suitable high temperature metal or alloy, or a ceramic, preferably Ni / Cr or an austenitic steel with chromium contents of at least 18%. The material would of course need to be selected to suit the temperature within the metal extraction unit required to produce the metal vapour. However, in a number of embodiments, the at least one moveable receptacle may be constructed from a high temperature metal or ceramic. In some embodiments, the at least one moveable receptacle is formed from a Ni / Cr alloy.

[0034] The drive unit may have a number of different forms depending on the configuration of the at least one movable receptacle. For example, the drive unit may comprise a motor configured to drive the rotation of an auger or screw feeder, drive wheel or conveyer. In some forms, the drive unit may comprise at least one drive wheel configured to drive movement of the at least one moveable receptacle through the feeding unit the metal extraction unit. Where the at least one movable receptacle a series of individual trays or a connected chain of trays, the drive unit may comprise a drive unit which engages and pushes the trays through the feed unit and the metal extraction unit. That drive wheel may include at least one rib, plate or paddle configured to contact and drive movement of the at least one moveable receptacle at least one moveable receptacle. More particularly, the drive wheel may include at least two paddles configured to seat at least one moveable receptacle therebetween. The drive wheel may be configured to rotate to push each moveable receptacle along a surface, through the feeding unit and the metal extraction unit. Alternatively, where the continuous chain or belt including recesses, such as tray recesses, that are driven by the drive wheel. The drive wheel speed may be adjustable via use of a Variable Frequency Drive. The speed of rotation of the drive wheel determines the residence time of the material inside the metal extraction unit. For example, the drive unit may be configured to move the at least one moveable receptacle at a speed of between 0.5 to 2 m / h, preferably 0.8 to 1.5 m / h, more preferably about 1 meter an hour through the metal extraction unit. It should be appreciated that drive unit is typically located outside of a heated zone of the thermal reduction apparatus, for example within a cool zone of the apparatus having a temperature of less than 100 °C.

[0035] The feeding unit and the metal extraction unit may include at least one gas bleed to create a gas flow through the respective units, and wherein at least one gas bleed in the metal extraction unit is located upstream of the internal space. This gas bleed may be located upstream of the heated internal spaces of the reducing until to form a gas flow in the direction of movement of the feed material through the metal extraction unit to assist in retaining the metal vapour in the hot zone of the metal extraction unit. However, other suitable position can be used depending on the configuration of the overall apparatus and atmosphere controlled chamber(s). Any metal vapour that finds itself outside of the metal extraction unit as metal on the cooler parts of the apparatus.

[0036] The condensers are by nature at a temperature which is below, typically well below the melting point of the metal being condensed. That temperature may be controlled to ensure recovery of metal from the vapour produced from the feed material. For the condensers may be controlled to a temperature of at least 300 °C, preferably between 300 and 600 °C, more preferably about 400 °C. At this temperature, the impurities will not likely settle on the heated surface of the condenser, but instead the impurities should travel through to a fluidly connected impurity collection unit, for example water cooled waste vessel. Each condenser may include a scraper arrangement configured to remove, preferably snap off, a metal deposit formed on the condenser. In embodiments, the metal deposit is removed with a scraper unit attached to an air operated ram with a flexible metal sealing boot. The removed metal deposit falls into a catch pot with a valve interlock to enable online collection.

[0037] The use of a residue collection unit and a residue collection unit further enhances continuous metal production by enabling continuous collection of the product metal and disposal of any residue. In this respect, the apparatus may also further comprise at least one metal collection unit located proximate the at least one condenser for collecting the sections of metal deposit removed from each collector. The metal collection unit may include a metal collection bin. The metal collection unit may be within the low pressure atmosphere within the atmosphere controlled chamber. Similarly, the apparatus may further comprise at least one residue collection unit following the metal extraction unit for collecting the feed material remaining in the at least one movable receptacle and any other residue material after exiting the metal extraction unit. For example, for magnesium production of magnesium oxide by thermal reduction, the amount of Mg left in the residue is aimed to be less than 4%. If the Mg content is higher than 4%, then reduce the residence time in the metal extraction unit may be altered to achieve a higher conversion, for example by slowing the speed of travel of the moveable receptacles through the metal extraction unit. The residue collection unit may include at least one vessel or container which includes an collection space into which the residue material and remaining feed material. The residue collection unit may be within the low pressure atmosphere maintained within the atmosphere controlled chamber.

[0038] The apparatus and units may be produced from any suitable material. In embodiments, the extraction unit is formed from a high temperature material, for example a high temperature metal or alloy, a refractory lined container, ceramic or a combination thereof. For example, the metal extraction unit may be constructed from Ni / Cr. The metal extraction unit may be constructed from Ni / Cr 150NB pipe schedule 40 or 80 with stiffening rings to help resist sucking in under the extreme high vacuum and high temperature environment. The length of the pipe may be 2.5 to 5 metres, and may be inclined at a slope of from 5 to 20° angle, for example a 14° angle sloping down to assist the trays in moving through the metal extraction unit.

[0039] Advantageously, the high temperature region within the metal extraction unit does not have any moving parts of valves, with the exception of the movable receptacle which progressively moves the feed material through the first space and then second space of the metal extraction unit. Material may be feed into the unit through a feed hopper, and egresses from the condenser and residue sections. Moreover, the loading of feed material into the at least one movable receptacle may occur inside the atmosphere controlled sections of the system / apparatus. Operators only need to fill the feed hopper and change the residue and metal collector bins. The feed material moving through the hot region of the metal extraction unit may not be disturbed in anyway.

[0040] A second embodiment provides a process of recovering a selected metal from a metal bearing feed material comprising: feeding a metal bearing feed material onto at least one movable receptacle; moving the metal bearing feed material into and through a metal extraction unit using the at least one movable receptacle; separating the selected metal from the metal bearing feed material as a metal vapour in the metal extraction unit under low pressure conditions; and cooling and condensing the metal vapour into a solid product, wherein the feeding, moving, and separating steps are conducted within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers.

[0041] This second embodiment to a continuous process of recovering a selected metal from a metal bearing feed material. As with the first embodiment, the feeding, moving, and separating steps may be conducted within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers. In this regard, the atmosphere controlled environment may be used to ensure that temperature and environment remains substantially constant throughout the apparatus. In addition, enclosing the key process units (feeding unit, metal extraction unit and at least one condenser) within a controlled atmosphere may facilitate good process control of the thermal reduction process, and control the influx of impurities that may otherwise enter the apparatus / system. Again, it should be understood that “low pressure” and “low pressure conditions” refers to the pressure being less than atmospheric pressure (i.e. less than ~100 kPa absolute (equivalent to 1 bar)). This low pressure may be created by a strong vacuum pump, which may be used to reduce the pressure to less than 100 Pa. For example, the low pressure may be from a pressure of less than 50 Pa, preferably from 5 to 50 Pa absolute, more preferably from 20 to 40 Pa absolute, yet more preferably from 25 to 35 Pa absolute. In some embodiments, the metal extraction process may be kept at its optimum, by maintaining the pressure to below 40 Pa.

[0042] The metal recovery process may be facilitated by the at least one movable receptacle being moved through the feeding step, thermal reduction step and then being returned back into position to receive further metal bearing feed material. This may enable the metal bearing feed material to be continuously fed through the system, for the separation and recovery of the selected metal.

[0043] In the separation step, a metal vapour is produced within the metal extraction unit. That metal vapour may be produced by boiling point differentiation of the selected metal and other components of the metal bearing feed material, or may be produced as a result of a reaction, for example a reduction reaction - such as a thermal reduction reaction. The process may therefore comprise one or more of: a thermal separation process, a metal distillation process, a reduction process, a thermal reduction process, or the like.

[0044] In some forms, this second may comprise a thermal reduction process capable of continuously producing a metal such as magnesium from a metal bearing feed material (for example a magnesium oxide containing feed material). In these forms, the separation step comprises thermally reducing the metal bearing feed material in the metal extraction unit to produce a metal vapour comprising the selected metal under low pressure conditions. Alternatively, this second embodiment may comprise a distillation process capable of continuously separating a selected metal such as magnesium, lithium or the like from a metal bearing feed material based on the differential boiling points of the components of the metal bearing feed material. In these forms, the separation step comprises separating the selected metal from the metal bearing feed material based on boiling point of said selected metal to produce the metal vapour.

[0045] Separating the selected metal from the metal bearing feed material typically involves heating the metal bearing material to a selected temperature. The process may include heating the metal bearing material to one selected temperature, or may include two or more different temperatures. These different temperatures can allow for differentiated extraction of parts of the metal bearing feed material. For example one temperature can be used to preferentially remove impurities, whilst a second temperature can be used to extract the selected metal as a metal vapour, thus producing a metal vapour of high purity that can be recovered on the respective condenser at a high purity. One example of high purity metal is greater than 99 % purity, more particularly greater than 99.5% purity, and more particularly greater than 99.7% purity. In this sense, separation of the selected metal from the metal bearing feed material as a metal vapour may be undertaken within the metal extraction unit in a single stage, or in two or more stages. In embodiments, the selected metal may be separated from the metal bearing feed material in at least two stages, comprising at least two different temperatures. For example, the metal bearing feed material may be heated within the metal extraction unit in at least two stages, comprising: heating the metal bearing feed material to between 200 to 1150 °C, preferably between 700 and 1150 °C, more preferably between 800 and 1100 °C to produce a first vapour substantially comprising any impurities within the feed material, and cooling and first vapour as a first solid product; and heating the metal bearing feed material to between 1100 and 1300 °C, preferably greater than 1150°C, more preferably at least 1200 °C to produce a second vapour substantially comprising a metal vapour, and cooling and condensing said first vapour as a second solid product.

[0046] The metal bearing feeding material may comprise any suitable feed material that can be deposited onto the movable receptacle. For example, the metal bearing feed material may comprise a particulate feed material, or a briquette. In embodiments, the particulate feed material may comprise any suitable particulate material such as a powder, pellet, grain, bead, pill or the like. The particulate feed material may therefore comprise a powder feed material or a pellet feed material at 25 ºC. The particulate feed material may comprise a mixed powder at 25 ºC (i.e. at or around ambient temperature) in some embodiments.

[0047] The selected metal that is recovered from the metal bearing feed material can comprise a variety of target metals. Examples of the selected metal includes at least one of lithium, calcium, magnesium, titanium, silicon or a rare earth metal

[0048] In some embodiments, the metal bearing feed material may comprise a metal that includes impurities that needs to be refined to increase the purity of the metal. For example, the metal bearing feed material may comprise magnesium having purity of less than 95 wt%, which is desired to be refined to a purity of greater than 99 wt%. Other metals that may benefit from distilling to purify may include titanium, calcium and silicon.

[0049] In some embodiments, the metal bearing feed material may comprise a metallic precursor material that may be thermally reduced to form the desired metal. That metallic precursor may comprise any suitable metallic salt or compound. For example, the metallic precursor may comprise a metal oxide. One example may be magnesium production in which the metallic precursor may comprise magnesium oxide.

[0050] Particular embodiments a thermal reduction apparatus for producing magnesium. Here, the feed material may comprise a magnesium oxide rich mixture that is mixed with a reductant and the metal product substantially comprises magnesium. Any suitable reductant may be used, for example the reductant may comprise aluminium, carbon, or at least one silicon, for example ferrosilicon. In some examples, calcium fluoride can be added as a catalyst for the reduction. Similarly, the composition of the MgO rich mixture may comprise any suitable MgO containing mixture, and that composition typically depends on the source material from which the MgO is produced. In embodiments, the MgO mixture may be formed from calcined dolomite. Dolomite typically comprises 60% calcium carbonate and 40% magnesium carbonate with trace impurities Na, K, Cl. These trace impurities remain in the MgO rich mixture and are preferably removed in the process in order to collect a pure Mg metal product. In other embodiments, the MgO rich mixture may result from other sources (mined magnesite (MgCO3), or magnesium chloride hydrolysed to hydroxide) may also include these and other impurities that are preferably removed in the Mg production process.

[0051] The movable receptacle(s) may have any suitable form that facilitates movement of the metal bearing feed material through the metal extraction unit. The at least one movable receptacle may comprise at least one recessed body, for example a container, and preferably a short walled container such as a tray. The container may include a walled cavity configured to hold the metal bearing feed material therein. For continuous metal production, a plurality of movable receptacles is typically desired, onto which metal bearing feed material may be continuously fed, and then moved into and through the metal extraction unit. Here, the at least one movable receptacle may comprise at least one of: a series of individual trays, a connected chain of trays, a continuous chain or belt including recesses, for example tray recesses, or an auger or screw feeder, that are driven by the drive unit. This series of trays, or chain / belt of recesses may cycle through the metal extraction unit, and be returned to the feeding unit to be refilled with metal bearing feed material. Moving the at least one movable receptacle may comprise operating at least one drive wheel which is operatively connected to the at least one movable receptacle to pull or otherwise translate the at least one movable receptacle through extraction unit. The at least one moveable receptacle may move through the metal extraction unit at any suitable speed that achieves the desired conversion and production of metal. In embodiments, the at least one moveable receptacle moves through the metal extraction unit at a speed of between 0.5 to 2 m / h, preferably 0.8 to 1.5 m / h, more preferably about 1 meter an hour through the metal extraction unit.

[0052] The cooling and condensing step is preferably conducted at a temperature of at least 300 °C, preferably between 300 and 600 °C, more preferably about 400 °C. As noted for the first embodiment, at this temperature, the impurities should not settle on the heated surface, but instead the impurities should travel through to an impurity collection unit, for example water cooled waste vessel.

[0053] The process may further comprise the step of: collecting the solid produced from the cooling and condensing step in at least one metal collection unit located proximate the at least one condenser. The metal collection unit may include a metal collection bin. The metal collection unit may be located within the low-pressure atmosphere maintained in the atmosphere-controlled chamber. The process may also further comprise the step of: collecting residual feed material that exits from the reducing using in at least one residue collection unit.

[0054] A third embodiment provides a metal produced using the process according to second embodiment. In embodiments, the metal produced by this process may comprise magnesium. It should be understood that the features described above for the first and second embodiments equally may be applied in this third embodiment.

[0055] A fourth embodiment provides a process of the second embodiment that may be conducted using the metal recovery apparatus according to the first embodiment. It should be understood that the features described above for the first and second embodiments equally may be applied in this fourth embodiment. BRIEF DESCRIPTION OF THE

[0056] The present invention will now described with reference to the figures of the accompanying drawings, which illustrate particular examples, wherein:

[0057] Figure 1 provides a process flow diagram of one example metal recovery process according to the present invention.

[0058] Figure 2 provides a schematic drawing showing a first example of the apparatus and continuous process according to the present invention configured to produce magnesium using the Pidgeon process.

[0059] Figure 3 provides a schematic drawing showing an example of the one condenser and metal collection system that can be used in the apparatus and continuous process illustrated in Figure 2. DETAILED DESCRIPTION

[0060] An apparatus and process / process is disclosed that allows for the continuous recovery of a metal from a metal bearing feed material. The apparatus and process are particularly configured for high temperature and low (near vacuum) pressure metal recovery processes. In this sense, the disclosed apparatus and process can be configured for the production of various metals using a thermal reduction route or for the purification or recovery of a selected metal by metal distillation processes.

[0061] Figure 1 provides one example of a general process flow diagram of the process system according to the present disclosure. The process following this process flow diagram is as follows: (A) A metal containing feed material 16 is fed or otherwise loaded into a feeding unit 10 that is configured to feed the metal containing feed material 16 into a movable receptacle (not illustrated) which are used to transport the feed material through a subsequent metal extraction unit 30. As described previously, the feeding unit may comprise various feeding configuration depending on the nature of the metal containing feed material. Similarly, the movable receptacle can have various forms, such as a tray or trays, a conveyer, an auger or a screw feeder as previously described. metal containing feed material 16 is transported from the feeding unit 10 a metal extraction unit 30. Movement of the movable receptacles is driven by a drive unit (not illustrated). Specific embodiments of the drive unit will be described in more detail below. (B) The metal extraction unit 30 is connected to the feeding unit 110 and generally comprises a heated vacuum retort arrangement in which a selected metal is separated from the metal containing feed material 16. That separation may be a result of a thermal reduction reaction, or alternatively as part of a metal distillation process (as described in more detail below in relation to the example apparatus illustrated in Figures 2 and 3). The metal extraction unit 30 includes a heat source, for example a furnace or similar, that enables an internal space therein to be heated. That internal space is under a low pressure (close to vacuum) to facilitate the production of vapour. (C) At least one condenser 40 is fluidly connected to the internal space of the metal extraction unit 30 and are operated to condense the metal vapour from the internal space to form a metal product thereon. The metal 44 is extracted as a product from the process. Impurities 43 or other material that evolves from the metal containing feed material 16 in the internal space of the metal extraction unit 30 can also be capture and / or recovered past the condenser or condensers 40. (D) Residue remaining after the selected metal separates from the metal containing feed material 16 is cleared out from (or otherwise removed from) the moveable receptacles in the residue collection unit 69. The movable receptacles are then returned to the feeding unit 10 via a movable receptacle return arrangement 68, to be filled with metal bearing feed material 16 ready to enter the metal extraction unit 30.

[0062] As shown by the broken lined box enclosing each process unit, the feeding unit, metal extraction unit, condenser 40, drive unit and residue collection sections are all contained within an atmosphere-controlled chamber 74. The atmosphere-controlled chamber 74 encloses a low-pressure atmosphere therein that is produced by a vacuum pump (described in more detail below) ensuring a controlled low-pressure atmosphere is present in those key units of this process and apparatus.

[0063] Specific selection of the that can be used within the process illustrated in Figure 1 depends on material composition and conditions that are used to recover the selected metal from the metal containing feed material within the metal extraction unit 30.

[0064] One example application of the process shown in Figure 1 is a thermal reduction process, such as the production of magnesium using the Pidgeon process. It should be appreciated that the Pidgeon process typically follows two steps:

[0065] STEP ONE: MgO production: Magnesium oxide may be obtained by sea or lake water magnesium chloride hydrolysed to hydroxide. In most cases, a magnesium raw material is calcined to produce a magnesium oxide rich precursor material. For example, for dolomite calcination - Dolomite typically comprises ~60% calcium carbonate and ~40% magnesium:

[0066] Another option is to use mined magnesite (MgCO3) calcined to magnesium oxide by carbon dioxide removal.

[0067] STEP TWO: Vacuum Thermal Reduction: The magnesium oxide rich precursor material is then thermally reduced under vacuum (low pressure conditions) to produce a magnesium vapour which is then condensed to a metal. Whilst a number of reducing agents may be used, the most common is a ferrosilicon mixture because it is cheaper and more readily available than silicon. The iron from the alloy is a spectator in the reaction:

[0068] The Pidgeon process is an endothermic reaction (△H° ~183.0kJ / mol Si). The reaction is placed in a better thermodynamic position (i.e. low temperature / energy requirements) by conducting the reaction at a lower pressure, thus the use of vacuum reduction for magnesium production.

[0069] This system provides a reduction apparatus for the second step of the process, where the rich precursor material is thermally reduced under vacuum (low pressure conditions) to produce a magnesium vapour which is then condensed to a metal.

[0070] Figure 2 provides a schematic drawing showing a first example of the new continuous system for recovering a metal from a metal containing bearing material. In this particular example, the apparatus is configured as a thermal reduction apparatus for the production of magnesium using the Pidgeon process (as described above). However, it should be appreciated that the apparatus can also be configured for other metal recovery / separation / refinement processes, such as metal distillation as will be described below.

[0071] Figure 2 illustrates the main sections of this thermal reduction apparatus 100 example. The illustrated thermal reduction apparatus 100 is formed within a vacuum chamber 104 (also known as an atmosphere-controlled chamber) that includes a main cylindrical vacuum body 105 that forms the main atmosphere- controlled chamber housing the feed and metal extraction units of the apparatus 100 therein. The vacuum chamber 104 includes a sealable access / pressure door 107 that allows access to the interior outside of operation of the apparatus. The access door 107 is sealed during operation. As described below, the vacuum chamber 105 includes a number of peripheral ports through which various other units of the apparatus connect into that chamber 105.

[0072] Referring to Figure 2, the main sections of the apparatus are: (A) A feeding unit 110, which in the illustrated embodiment comprises a particulate hopper 112 and screw conveyer 113 that is configured to feed particulate feed material 116 into one of a series of movable feed trays 120. (B) A metal extraction unit 130 which is connected to the feeding unit 110. The metal extraction unit 130 comprises a vacuum retort arrangement in which a thermal reduction reaction of the particulate feed material 116 occurs which produces a metal vapour 135, 136. As will be described below in more detail, the metal extraction unit 130 includes a divided internal space 135A which is heated and is under vacuum (low which the thermal reduction reaction undergoes. The metal extraction unit is enclosed within a furnace 133, which is operated to heat the internal space 135A of the metal extraction unit 130 to the required thermal reduction reaction temperature. (C) Two condensers 140, 142 set within vapour collection conduits 150, 152 connected to the internal space 135A of the metal extraction unit 130 which are operated to condense the metal vapour from the internal space 135A to form a metal product thereon. (D) A drive unit 160 for driving movement of the movable feed trays 120 though the feeding unit 110 and the metal extraction unit 130. In the illustrated embodiment, that movement comprising sliding the feed trays 120 over a flat surface of deck 162 which is shared across the base of each of the feeding unit 110 and the metal extraction unit 130. (E) A residue collection unit 169 where residue remaining after magnesium is separated from the particulate feed material 116 is collected from the movable feed trays 120. (F) An atmosphere control system 170 including the vacuum chamber 104 (an atmosphere control chamber) in which each of the units 110, 120, 130, 140, 150, 160 are contained. As above, the overall vacuum chamber 104 comprises a main cylindrical body 105 that houses part of the feeding unit 110 and the metal extraction unit 130, with the drive unit 160 and condensers 140, 142 and parts of the feeding unit 110 being connected to and extending from that main cylindrical body 105. The overall vacuum chamber 104 encloses a low pressure atmosphere therein that is produced by a vacuum pump (described in more detail below).

[0073] The various parts of the apparatus illustrated in Figure 2 will now be described in more detail: 1. The Drive Unit 160

[0074] The illustrated drive unit 160 comprises drive wheel 164 situated in the apparatus in a drive chamber 161 in an annex to the main cylindrical body 105 of the vacuum chamber 104. The drive chamber 161 and drive wheel are located outside of the furnace 133 in a cool zone (typically around 40 °C) of the circuit.

[0075] The illustrated drive wheel a rotating wheel that includes a series of circumferentially spaced paddle plates, for example steel paddle plates, that are configured with spacing that the feed trays fit neatly between. The illustrated wheel includes seven paddles. However, it should be appreciated that any number of paddles could be used depending on the size of the feed trays 110 and the size of the apparatus 100. In operation, the drive wheel 164 rotates pushing the feed trays 120 on to the deck 162 where they slide along the deck 162 in a line of abutting feed trays 120 through the feeding unit 110 where the particulate feed is dispensed into the feed tray 120, and then through the metal extraction unit 130. The front and end of adjoining feed trays 120 abut, so to form a line along the deck 162 which is driven (pushed) by the rotation of the drive wheel 164 and the addition of a further feed tray 120 that chain. Once the feed tray 120 is pushed out from the metal extraction unit 130, it falls into a chute 166 where it is inverted to tip any residue material contained after exiting the metal extraction unit 130, and is then transported, in this instance by a chain driven tray return mechanism 168 back to the drive wheel 164, ready to be placed onto the deck 162, into the tray line, to be pushed into the feeding unit 110 to receive further particulate feed. The feed trays 120 move at a speed of between 0.5 to 2 m / h, preferably 0.8 to 1.5 m / h, more preferably about 1 meter an hour through the metal extraction unit 130.

[0076] Whilst not illustrated, the drive wheel 164 may be driven by an external gear drive via a sealed rotary feed through arrangement (not illustrated). The rotation speed of the drive wheel 164 is adjustable through the use of a variable frequency drive (not illustrated). The speed of rotation of the drive wheel 164 determines the residence time of the material inside the metal extraction unit 130. The speed may be adjusted to provide the required product conversion of the thermal reduction reaction, for example slowed down to increase residence time within the internal space 135A of the metal extraction unit if the required conversion is not achieved.

[0077] The feed trays 120 may comprise a metal tray having recess provided between four walls. In the illustrated embodiments, the trays are made of 2 mm thick Ni / Cr alloy and are 100 mm x 115 mm in width and length, and are 20 mm in height. However, it should be that these dimensions can be adapted to suit a particular size and the like.

[0078] The feed tray 120 chain may be formed from a series of disconnected, or loosely connected trays as illustrated in Figure 2. However, it should be appreciated that the feed trays 120 could equally form part of a tray conveyer belt or other connected chain of trays that are driven by the drive wheel 164 as a chain or a belt around the driven pathway of the system. Alternatively, an auger or other screw conveyer type material transporter could also be used to transport the particulate feed material 116 through the apparatus 100, and in particular through the metal extraction unit 130. 2. Feeding unit 110

[0079] The main cylindrical body 104 of the vacuum chamber 105 is largely split into a feeding unit zone 111 and a metal extraction unit 130 by baffle 138A (described in more detail below).

[0080] Starting first with the feeding unit 110, and the feeding unit zone 111, this unit 110 comprises a particulate hopper 112 and screw conveyer 113 that is configured to feed particulate feed material 116 into one of a series of movable feed trays 120 located in the feeding unit zone 111 within the cylindrical body 105.

[0081] The feed hopper 112 comprises any suitable particulate / powder feeding hopper which may be held at low pressure under vacuum. This low pressure may be retained therein by filling the hopper 112 using a valve interlock system (not illustrated) with Argon shield / cover gas. An argon gas bleed 117 (input bleed) is used to keep the feed fresh, with the added argon passing through the hopper from the vacuum chamber 104, and passing into the metal extraction unit 130. It should be appreciated that the atmosphere control system 170 will be operated to maintain the low pressure conditions within the vacuum chamber 104, including balancing any addition pressure that may be introduced therein from the argon gas bleeds 117 and 137.

[0082] The particulate feed material can have any suitable form such as powder or pellet form at ambient (25 ºC) and drops from the hopper 116 into the screw feeder 114, assisted by an intermittent vibrator (not illustrated). Alternatively, briquettes could be used that are fed using a suitable briquette feeder. The screw of the screw conveyer 114 is driven by an external motor via a sealed rotary feed through arrangement (not illustrated) and is variable speed with an intermittent timer to resist bridging of feed material. The particulate feed material 116 is dispensed from the screw feed 114 through feed pipe 117 which connects via a port into feeding unit zone 111 and falls into the feed trays 120 positioned there under. That fed particulate feed material 116 may optionally be spread evenly for uniform thickness by use of a plate feed comb (not illustrated) prior to entry into the metal extraction unit 130.

[0083] The apparatus 100 illustrated in Figure 1 is preferentially configured to produce magnesium using the Pidgeon process. However, it should be appreciated that it could equally be configured for other metal recovery processes that use a thermal reduction process. In these embodiments, the particulate feed material 116 comprises a MgO rich mixture that is mixed with a reductant mixture, for example ferrosilicon. As described above, the MgO rich mixture may be formed from calcined dolomite. Dolomite typically comprises 60% calcium carbonate and 40% magnesium carbonate with trace impurities Na, K, Cl. These trace impurities remain in the MgO rich mixture and are preferably removed in the process in order to collect a pure Mg metal product. Similarly, an MgO rich mixture from other sources (mined magnesite (MgCO3), or magnesium chloride hydrolysed to hydroxide) may also include these and other impurities that are preferably removed in the Mg production process. 3. Metal extraction unit 130 (retort section)

[0084] The metal extraction unit 130 comprises a heated vacuum retort unit. As illustrated, the metal extraction unit 120 comprises a section of the main cylindrical body 105 which is located within a furnace 133. The furnace 133 is configured to heat the internal space 135A within the metal extraction unit 120 to a high temperature – for example 1200 ºC for the production of magnesium.

[0085] As illustrated, the internal 135A within the metal extraction unit 130 is divided into two heated spaces, a heated space 136 and a second heated space 137 that are defined therein using three spaced apart baffle plates 138A, 138B, 138C. The three baffle plates 138A, 138B, 138C are spaced apart along the direction of movement of the feed trays 120 through the metal extraction unit 130 to enable the removal of vapours emitted at different temperatures as the feed material is heated moving through the first heated space 136 and a second heated space 137 of the metal extraction unit 130. The first baffle plate 138A and the third baffle plate 138C are positioned at the respective start and end of the internal space 135A defining the metal extraction unit 130. These baffle plates 138A, 138C border the hot zone where the furnace 133 starts and ends. The first baffle plate 138A separates the metal extraction unit 130 from the feeding unit zone 111 within the main cylindrical body 104 of the vacuum chamber 105. An optional second baffle plate 138B is positioned between the first baffle plate 138A and the third baffle plate 138C. The illustrated baffles plates comprise a sheet or plate configured to direct vapour produced from heating the feed product within the adjoining internal space towards the respective fluidly connected condenser 140, 142. Each baffle plate 138A, 138B, 138C includes guide sections configured to space the baffle plates 138A, 138B, 138C away from the feed trays 120 moving across the deck 162. The guide sections ensure that the baffle plates 138A, 138B, 138C avoid snagging the feed trays 120 as they move through the metal extraction unit 130.

[0086] Each of the first heated space 136 and the second heated space 137 have a vapour collection conduit 150, 152 that fluidly leads to a specific condenser 140, 142. Each vapour collection conduit 150, 152 comprise pipes that are sealed to and extend out from the main cylindrical body 105 of the vacuum chamber 104. The vapour collection conduits 150, 152 comprise pipes which extend from the main body 130A section of the metal extraction unit 120, extend out from the furnace to the condenser section 140A of the apparatus 100. The illustrated vapour collection conduit 150, 152 comprise twin 100 mm Nominal Bore (NB) pipe conduits that extend out of the furnace 133 enclosure and are kept above 900 °C by use of electric / ceramic pipe heaters (not illustrated).

[0087] The first vapour collection 150 is connected to the first heated space 136, and is positioned to vapours from feed trays 120 entering the metal extraction unit (heated by furnace 133) that are heated to between ~200 °C to 1150 °C. In this temperature range, the impurities such as Na, K, Cl, H2O and CO2 are primarily emitted from the heated particulate feed 116. The second collection conduit 152 is connected to the second heated space 137, and is positioned to collect vapours from feed trays in which the feed material has reached the top temperature (from its initial temperature of less than 100 ºC from the feeding unit 110). In the illustrated embodiment, that top temperature is greater than 1150 °C, for example around 1200 °C. At this temperature, Mg metal is primarily evolved as a vapour from the particulate feed material 116.

[0088] The different temperatures in the the first heated space 136 and the second heated space 137 can be produced in the illustrated embodiments by utilising the progressive heating of the particulate feed material 116 from feed temperature (typically less than 100 °C) to the temperature within the heated zone (around 1200 °C). Movement of the particulate feed material 116 through the internal space 135A of the metal extraction unit 130 progressively move that metal bearing feed material through the first heated space 136 through to the second heated space 137, as well as progressively heating the feed material 116 in the temperature zones indicated above. The speed of movement of the particulate feed material 116 through the internal space 135A and heating rate of the particulate feed material 116 can be used to selectively extract impurities and metal as explained above. Alternatively, each of the first heated space 136 and the second heated space 137 may have different or separate heat sources that can be controlled to produce a different temperature within the different heated zones.

[0089] A small argon gas bleed 137 is included up stream of the third baffle plate 138C to keep the magnesium vapour in the hot zone (i.e. metal extraction unit sections within the furnace 133). Any Mg vapour that finds itself on the wrong side of the baffle plates 138A, 138C may deposit as metal on the cooler parts of the apparatus. This is not considered a problem by the Inventors as this metal may assist in forming a closer gap between the feed tray 120 and the respective baffle plate 138A, 138C and thereby a lower Argon gas purge. Any metal accumulations will likely also be off by the movement of the feed tray line.

[0090] When included in the apparatus, the function of the second baffle plate 138B (middle baffle plate) is to assist in funnelling the impurities such as Na, K, Cl, H2O and CO2 evolved from the heated particulate feed within the first heated space 136 towards the first condenser 140. This assists in producing a pure Mg vapour within the second heated space 137. Here substantially all of the metal vapour produced in the second heated space 137 (not mixed with vapour from the first heated space 136) can be funnelled towards the second condenser 142, enabling that condenser 142 to harvest a high purity Mg metal from the metal vapour produced in the second heated space 137. The Mg metal recovered on the second condenser 142 typically does not require refining.

[0091] The impurities within the particulate feed material 116 are liberated at a lower temperature than the Mg metal vapour. A smaller amount of Mg metal will consequently be solidified on the first condenser 140 because the particulate feed material 116 in the feed tray 120 will not or will have only just reached the temperature where Mg Vapour is formed before it passes through the second baffle plate 138B into the second heat space 137. The Mg metal from the first condenser 140 therefore may require refining. 4. Condensers

[0092] The two condenser 140, 142 are described in more detail below. The condensers 140, 142 are controlled to ~400 °C and are positioned inside each of the vapour collection conduit 150, 152. At this temperature, any impurities liberated from the particulate feed material 116 should not settle on the heated surface of the condensers 140, 142, but will instead travel past the condensers 140, 142 through to an impurity collection unit, in the illustrated embodiment comprises water cooled waste pot 145. In operation, the Mg vapour travels from a temperature of around 1200 ºC from the metal extraction unit 130, through the vapour collection conduits 150, 152 (typically at around 800 ºC), and condense on the condensers 140, 142 controlled at ~400 °C (see below). Vapour or gases travelling past the condensers 140, are generally at 200 °C when exiting the waste pot 145 (see Figure 3).

[0093] Figure 3 provides a schematic drawing showing an example of a condenser system 140A showing one condenser 140 or 142 and metal collection system that can be used in the apparatus 100 illustrated in Figure 2. The illustrated condenser 140 / 142 comprises a polished steel frustoconical body having about a 2 degree taper. The frustoconical body is hollow and includes a hollow body 174 that forms a sealed chamber therein. The sealed chamber includes an air cooling system 176 that includes a cooling air input 176A and air outlet 176B allowing cooling air to flow through the sealed chamber to maintain that temperature of the frustoconical body at around 400 ºC. The condenser system 140A also includes a metal scraping system 178 comprising a sliding pipe section 179 which is periodically (around every 30 minutes) driven downwardly (relative to the orientation shown in Figure 3) over the frustoconical body to scrape deposited metal 180, in this case Mg metal, that has been deposited on the outer surface of the condenser 140 / 142. The sliding pipe 179 includes cutout sections 187 to accommodate the pipes / conduits of the air cooling system 176. The scraped metal deposit 181 falls into a metal collection unit 182, typically a metal collection pot 182A with a valve interlock 183 to enable online collection through removal and / or exchange of the metal collection pot 182A.

[0094] As noted above, the Mg metal deposit is removed from each condenser 140, 142 using a scraper mechanism comprising a sliding pipe section 179 which is attached to a hydraulic Ram 184 that has a flexible metal sealing boot (not illustrated). The scraper operates to snaps off the Mg metal crown formed on the respective condenser 140, 142 and then is configured to withdraws into a snug fit housing 185 to negate any long term metal accumulation. The metal scraping system 178 is also in deep vacuum, being fluidly connected with the vacuum chamber 104. An argon purge 188 is located at the top fi the metal scraping system 178.

[0095] It should be appreciated that the distance between the two condenser 140, 142 can be designed to optimise the selectivity of vapour composition condensed on the respective condenser 140, However, that distance is a function of a number of parameters of the including particulate feed material 116 composition, design and speed of the drive unit 160, design of the metal extraction unit and the like. However, it should be appreciated that the fitment of the middle baffle 138B between the vapour collection conduits 150, 152 would have a stronger influence on the vapour distribution. 5. Vacuum Chamber 104

[0096] The atmosphere control system 170 also includes a vacuum pump (not illustrated) which produces the low pressure atmosphere within the vacuum chamber 104. In the illustrated arrangement, the vacuum pump is fluidly connected to the vacuum chamber 104 through the water cooled waste pot 145. However, it should be appreciated that this could be positioned in any other suitable position in the illustrated apparatus 100. A generic paper filter is typically placed between the waste pot and the vacuum pump. The vacuum pump may be any suitable low pressure pump. In the illustrated example, a Rootes / Claw type pump is used that is capable of high flow and producing a deep vacuum. The pressure in the metal extraction unit 130 and thus the vacuum chamber 104 during operation is less than 50 Pa, typically between 25 to 35 Pa absolute. When the feeding is stopped the pressure may be ~ 8 Pa. To keep the metal extraction process at its optimum, it is preferable to keep the pressure within the metal extraction unit 130 to be below 40 Pa. The atmosphere control system 170 may also include a control unit (not illustrated) that operates the vacuum pump and Ar bleeds 117, 137 to control the atmospheric conditions (pressure, composition and the like) within the vacuum chamber 104.

[0097] The units of the apparatus 100 are fully enclosed within the vacuum chamber 104 under deep vacuum (i.e. pressure less than 100 Pa, preferably less than 50 Pa). Any dust that is present will settle quickly as there is little or no atmosphere to suspend the fine particles. It is noted that dust is an impurity that may find its way into the condenser metal crown. Temperature and environment remains constant within the vacuum chamber 104 throughout the operation of the apparatus 100. There is no opening and closing of the vacuum chamber 104 during operation. The metal extraction unit 130 section is expected to last much longer under these conditions, an important consideration when using the Pidgeon process.

[0098] The vacuum chamber 104 may have any suitable configuration. In the illustrated embodiments, the atmosphere controlled chamber 104 comprises one main vacuum chamber body (main cylindrical body 105) which is divided into at least the feeding unit zone 111, and the metal extraction unit 130 using baffle 138A. However, it should be appreciated that this could equally be configured as two or more connected vacuum chambers, as opposed to one single chamber with peripheral connections. 5. Residue collection

[0099] Any spillage of particulate feed material 116 that misses the feed tray and lies on the deck 162 should not be detrimental to the process. In fact, it may assist the feed trays 120 in sliding along the deck 162 with less drive wheel force required.

[0100] After passing through the metal extraction unit 130, the feed tray 120 will contain some solid residue, which will cool down. The feed tray 120 will be pushed off the end 163 of the deck 162 and into a chute 166, comprising a conduit that is connected to the end of the main cylindrical body 105 of the vacuum chamber 104. The feed tray 120 will then slide down the chute 166 where it rapidly changes direction and is turned upside down. The contents of that feed tray 120 is emptied into the residue collection unit, a residue collection pot 169. A valve interlock (not illustrated) with Argon gas injection is provided to enable changing pots 169 while the apparatus 100 is still in operation. The amount of Mg left in the residue is preferably less than 4%. If this content is found to be is higher, then the speed of rotation of the drive wheel 164 may be reduced to achieve a longer residence time within the metal extraction unit 130.

[0101] Where magnesium is produced from Dolomite using the Pidgeon process, the residue formed once the magnesium metal is separated from the particulate feed material 116 may substantially comprise a Portland cement. In this regard, the chemistry of the MgO rich mixture, particularly when sourced from dolomite, may be augmented with a calcium material, for example lime, to produce a Portland cement The residue (typically comprising around 80% of the mass of the metal bearing feed material) can therefore provide a secondary commercial product created from that feed material. 6. Feed tray return

[0102] After the feed tray 120 is emptied, the empty feed tray 120 rests at a point past the residue collection pot 169 and waits for a trigger to start a return journey to the drive wheel 164. The orientation of the drive wheel 164 will activate an electromechanical switch at a precise time which in turn activates a gear drive to start a chain driven tray transfer mechanism 168, or other arrangement. A weighted roller assembly at the drive wheel 164 end is used to ensure that the returned feed tray 120 is seated securely between the paddles 165 of the drive wheel 164. This activity may be controlled by the VFD for the gear drive (not illustrated). However, it should be appreciated that alternate return arrangements could equally be used.

[0103] The apparatus 100 therefore does not have any moving parts or valves in the high temperature region within the metal extraction unit 130, only the tray of material that slides along a flat surface of the deck 162. Moreover, the loading and unloading of the feed trays 120 is automated and happens inside the atmosphere-controlled environment of the apparatus 100. Operators only need to fill the feed hopper and change the residue pot 169 and metal collection pot (not illustrated). The feed material moving through the hot region of the Retort is not disturbed in anyway. It is transferred only when it is in cooler areas of the apparatus 100. 7. Materials of Construction

[0104] The illustrated apparatus 100 is constructed as a vacuum chamber 104 formed from a cylindrical pipe constructed from Ni / Cr 150NB pipe schedule 40 or 80 with stiffening rings to help resist sucking in under the extreme high vacuum and high temperature environment. The length of the illustrated pipe is 2.5 metres. However, it should be appreciated that any suitable length could be used depending on the size and configuration of the apparatus. In some embodiments, the metal extraction unit 130 could long as 5 metres giving higher yields in the same time. However, the metal unit 130 is over 2.5 meters long, it may need to be inclined at a 14° angle sloping down to assist the feed trays 120 in moving in a sliding manner along the deck 162.

[0105] The feed trays may be constructed from any suitable high temperature metal, refractory or ceramic. However, it should be appreciated that metal trays at 1200 °C may lose a lot of their strength and may buckle if the force from the drive wheel 164 pushing the feed trays 120 along the deck 162 is too high. Ceramic feed trays 120 may be used. However, a metal substrate has a vastly different heat coefficient to the residue, and this will assist in the release of particles from the feed tray 120 after some cooling.

[0106] It is important that there is no air ingress into the vacuum chamber 104, and more particularly the metal extraction unit 130. Three rotary feed through devices are provided (not illustrated) and numerous valve seals (not illustrated) that are positioned away from the heated zone of the furnace 133. These cooler temperatures enable generic silicone and elastomer seals to be used throughout the apparatus 100 providing excellent sealing for a long time. Finally, whilst not illustrated, cooling of the apparatus 100 outside of the furnace is achieved using has water cooled copper lines wrapped around the pipe on either side of the furnace 133.

[0107] Another example application of the process shown in Figure 1 is metal distillation in aid of purification or refining of a metal, for example magnesium. Metal distillation is the thermodynamics process using the difference of boiling points of metal alloy to separate the different metal constituents from each other, as well as from any impurities therein. In a distillation system, condensing elements can be aligned with the different boiling points of the constituents to enable these selected metals to be selectively condensed and purified.

[0108] A second example of the new continuous system for recovering a metal from a metal containing bearing material can also be described with reference to Figure 2. In this particular example, the apparatus 100 is configured as metal distillation apparatus for the of magnesium. It should be appreciated that the various units of the are substantially the same as described above for the first embodiment.

[0109] In this embodiment, the metal extraction unit 130 is configured to purifying magnesium from the impurities within the magnesium containing feed material 116 using the difference of boiling points of the metals therein and any impurities therein.

[0110] In this regard, the internal space 135A within the metal extraction unit 130 is again divided into two heated spaces, a first heated space 136 and a second heated space 137 that are defined therein using three spaced apart baffle plates 138A, 138B, 138C as described above for the first example. Each of the first heated space 136 and second heated space 137 have a vapour collection conduit 150, 152 that fluidly leads to a specific condenser 140, 142. In this distillation system, the condenser 140, 142 are aligned with the different boiling points of the constituents to enable these selected metals to be selectively condensed and purified. Here, the first heated space 136 is configured to vaporise impurities from the feed material 116, whilst the second heated space 137 is configured to vaporise / boil magnesium. The impurities emitted from the heated feed material 116 within the first heated space 136 is directed towards the first condenser 240, allowing the second condenser 142 to harvest a higher purity Mg metal from the metal vapour produced in the second heated space 137, producing a higher purity Mg, for example greater than 99 % purity, more particularly greater than 99.5% purity, and more particularly greater than 99.7% purity. The impurities within the feed material 116 are liberated at a lower temperature than the Mg metal vapour.

[0111] Finally, it should be appreciated that the process and apparatus illustrated and described in relation to in Figures 1 to 3 could also be configured to produce magnesium using a distillation process with no substantive changes to the apparatus and process.

[0112] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the includes all such variations and modifications which fall within the scope of the present invention.

[0113] Where the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other feature, integer, step, component or group thereof.

Claims

CLAIMS 1. A metal recovery apparatus for recovering a selected metal from a metal bearing feed material, the apparatus comprising: a feeding unit configured to feed the metal bearing feed material onto at least one movable receptacle; a metal extraction unit which is connected to the feeding unit, the metal extraction unit including an internal space which is heated and in which the selected metal is separated from the metal bearing feed material as a metal vapour; at least one condenser which is fluidly connected to the internal space of the metal extraction unit to condense the metal vapour from the internal space to form a metal product; and a drive unit for driving movement of the at least one movable receptacle though the feeding unit and the metal extraction unit, wherein the feeding unit, the metal extraction unit, the at least one condenser, and the movable receptacles therein are enclosed within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers.

2. The metal recovery apparatus according to claim 1, wherein the at least one movable receptacle is configured to be returned to the feeding unit to receive further metal bearing feed material after the at least one movable receptacle exits the metal extraction unit.

3. The metal recovery apparatus according to claim 2, wherein the drive unit drives movement of the at least one moveable receptacle to be returned to the feeding unit.

4. The metal recovery apparatus according to any preceding claim, wherein the drive unit is enclosed within the atmosphere controlled chamber.

5. The metal recovery apparatus according to any one of claims 1 to 4, comprising a thermal reduction apparatus, wherein in the metal extraction unit athermal reduction reaction of the bearing feed material occurs that produces a metal vapour.

6. The metal recovery apparatus according to any one of claims 1 to 4, comprising a distillation apparatus, wherein in the metal extraction unit the metal is separated from the metal bearing feed material based on boiling point of said selected metal to produce the metal vapour.

7. The metal recovery apparatus according to any preceding claim, wherein the internal space of the metal extraction unit is sequentially divided into at least two heated spaces in a movement direction of the feed material through the metal extraction unit, each heated space being connected to a separate condenser.

8. The metal recovery apparatus according to claim 7, wherein said at least two spaces comprise at least a first heated space, and a second heated space, and wherein a first condenser is fluidly connected to the first heated space of the metal extraction unit to condense a first metal vapour from the first heated space; and a second condenser is fluidly connected to the second heated space of the metal extraction unit to condense a second metal vapour from the second heated space.

9. The metal recovery apparatus according to claims 7 or 8, wherein the first heated space is configured to heat the feed material to a temperature in which impurities from the feed material are substantially vapourised, and the second heated space is configured to heat the feed material to a temperature in which metal in the feed material is substantially vapourised.

10. The metal recovery apparatus according to any one of claims 7 to 9, wherein each of the first heated space and the second heated space have a vapour collection conduit that is in fluid communication with the respective fluidly connected condenser.

11. The metal recovery apparatus according to any one of claims 7 to 10,wherein the first heated space configured to enclose and heat the metal bearing feed material therein to 200 to 1150 °C, preferably between 700 and 1150°C, more preferably between 800 and 1100 °C; and wherein the second heated space is configured to enclose and heat the metal bearing feed material therein to between 1100 and 1300 °C, preferably greater than 1150°C, more preferably at least 1200 °C.

12. The metal recovery apparatus according to any one of claims 7 to 11, wherein the internal space of the metal extraction unit is sequentially divided into at least two heated spaces in a movement direction of the feed material through the metal extraction unit by at least one baffle.

13. The metal recovery apparatus according to claim 12, wherein the at least one baffle comprises a first baffle, a second baffle and a third baffle, the first and third baffles being positioned at or proximate the ends of the internal space, and the second baffle being positioned between the first and third baffles to divide the internal space into the first heated space and the second heated space.

14. The metal recovery apparatus according to claim 12 or 13, wherein each baffle comprises a sheet, plate or membrane.

15. The metal recovery apparatus according to claim 12, 13 or 14, wherein each baffle includes guide sections configured to space the baffles away from the at least one movable receptacle.

16. The metal recovery apparatus according to any preceding claim, wherein the metal extraction unit includes or is located within a heated enclosure.

17. The metal recovery apparatus according to any preceding claim, wherein the metal bearing feeding material comprises a particulate feed material, or a briquette.

18. The metal recovery according to claim 17, wherein the particulate feed material comprises a powder feed material or a pellet feed material at 25 ºC, and preferably a mixed powder at 25 ºC.

19. The metal recovery apparatus according to any preceding claim, wherein the selected metal comprises at least one of lithium, calcium, magnesium, titanium, silicon, or a rare earth metal.

20. The metal recovery apparatus according to any preceding claim, comprising a thermal reduction apparatus for producing magnesium, wherein the feed material comprises a magnesium oxide rich mixture that is mixed with a reductant, and the metal product substantially comprises magnesium.

21. The metal recovery apparatus according to claim 20, wherein the reductant comprises aluminium, carbon or at least one silicate, preferably ferrosilicon.

22. The metal recovery apparatus according to any preceding claim, wherein the feeding unit includes a feed hopper configured to feed the metal bearing feed material onto the at least one movable receptacle.

23. The metal recovery apparatus according to any preceding claim, wherein the at least one movable receptacle comprises at least one recessed body, preferably at least one tray.

24. The metal recovery apparatus according to any preceding claim, wherein the at least one movable receptacle comprises at least one of: a series of individual trays, a connected chain of trays, a continuous chain or belt including recesses, or an auger or screw feeder, that are driven by the drive unit.

25. The metal recovery apparatus according to any preceding claim, wherein the drive unit comprises at least one drive wheel configured to drive movement of the at least one moveable receptacle through the feeding unit and the metal extraction unit.

26. The metal recovery to claim 25, wherein the drive wheel includes at least one rib, or paddle configured to contact and drive movement of the at least one moveable receptacle at least one moveable receptacle.

27. The metal recovery apparatus according to any preceding claim, wherein the feeding unit and the metal extraction unit include at least one gas bleed to create a gas flow through the respective units, and wherein at least one gas bleed in the metal extraction unit is located upstream of the internal space.

28. The metal recovery apparatus according to any preceding claim, wherein the condensers are controlled to a temperature of at least 300 °C, preferably between 300 and 600 °C, and more preferably about 400 °C.

29. A process of recovering a selected metal from a metal bearing feed material comprising: feeding a metal bearing feed material onto at least one movable receptacle; moving the metal bearing feed material into and through a metal extraction unit using the at least one movable receptacle; separating the selected metal from the metal bearing feed material as a metal vapour in the metal extraction unit under low pressure conditions; and cooling and condensing the metal vapour into a solid product, wherein the feeding, moving, and separating steps are conducted within an atmosphere controlled chamber or fluidly linked atmosphere controlled chambers.

30. The process according to claim 29, further comprising moving the at least one movable receptacle out from the metal extraction unit, and back into position to receive further metal bearing feed material.

31. The process according to claim 29 or 30, wherein the separation step comprises thermally reducing the metal bearing feed material in the metalextraction unit to produce a metal comprising the selected metal under low pressure conditions.

32. The process according to claim 29 or 30, wherein the separation step comprises separating the selected metal from the metal bearing feed material based on boiling point of said selected metal to produce the metal vapour.

33. The process according to any one of claims 29 to 32, wherein the low pressure conditions comprise a pressure of less than 50 Pa, preferably from 5 to 50 Pa absolute, more preferably from 20 to 40 Pa absolute, yet more preferably from 25 to 35 Pa absolute.

34. The process according to any one of claims 29 to 33, wherein the selected metal is separated from the metal bearing feed material in at least two stages, comprising at least two different temperatures.

35. The process according to claim 34, wherein the at least two stages comprise: heating the metal bearing feed material to between 200 to 1150 °C, preferably between 700 and 1150 °C, more preferably between 800 and 1100 °C to produce a first vapour substantially comprising any impurities within the feed material, and cooling and condensing said first vapour as a first solid product; and heating the metal bearing feed material to between 1100 and 1300 °C, preferably greater than 1150 °C, more preferably at least 1200 °C to produce a second vapour substantially comprising a metal vapour, and cooling and condensing said first vapour as a second solid product.

36. The process according to any one of claims 29 to 35, wherein the metal bearing feeding material comprises a particulate feed material, or a briquette.

37. The process according to claim 36, wherein the metal bearing feed material comprises a powder feed material or a pellet feed material at 25 ºC, and preferably a mixed powder at 25 ºC.

38. The process according to of claims 29 to 37, wherein the feed material comprises a magnesium rich mixture that is mixed with a reductant, and the solid product substantially comprises magnesium.

39. The process according to claim 38, wherein the reductant comprises at aluminium, carbon, or least one silicate, preferably ferrosilicate.

40. The process according to any one of claims 29 to 39, wherein the at least one movable receptacle comprises at least one of: a series of individual trays, a connected chain of trays, a continuous chain or belt including recesses, or an auger or screw feeder.

41. The process according to any one of claims 29 to 40, wherein moving the at least one movable receptacle comprises operating at least one drive wheel which is operatively connected to the at least one movable receptacle to push, pull or otherwise translate the at least one movable receptacle through the metal extraction unit.

42. The process according to any one of claims 29 to 41, wherein the at least one moveable receptacle moves through the metal extraction unit at a speed of between 0.5 to 2 m / h, preferably 0.8 to 1.5 m / h, more preferably about 1 meter an hour through the metal extraction unit.

43. The process according to any one of claims 29 to 42, wherein the wherein the cooling and condensing step is conducted at a temperature of at least 300 °C, preferably between 300 and 600 °C, more preferably about 400 °C.

44. A metal produced using the process according to any one of claims 29 to 43, wherein the metal substantially comprises magnesium.

45. The process according to any one of claims 29 to 44 conducted using the metal recovery apparatus according to any one of claims 1 to 28.

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