Abstract: A method of controlling particle additions to a fluidized bed reactor includes measuring pressure fluctuations inside the fluidized bed reactor over a selected time period, determining a pressure parameter indicative of amplitudes of the pressure fluctuations, comparing the pressure parameter to a specified threshold, and controlling particle additions to the fluidized bed reactor when the pressure parameter deviates from the specified threshold.

Abstract: A method of controlling particle additions to a fluidized bed reactor includes measuring pressure fluctuations inside the fluidized bed reactor over a selected time period, determining a pressure parameter indicative of amplitudes of the pressure fluctuations, comparing the pressure parameter to a specified threshold, and controlling particle additions to the fluidized bed reactor when the pressure parameter deviates from the specified threshold.

Abstract: This disclosure concerns embodiments of an annealing device and a method for annealing flowable, finely divided solids, such as annealing granular silicon to reduce a hydrogen content of the granular silicon. The annealing device comprises at least one tube through which flowable, finely divided solids are flowed downwardly. The tube includes a heating zone and (i) a residence zone below the heating zone, (ii) a cooling zone below the heating zone, or (iii) a residence zone below the heating zone and a cooling zone below the residence zone. An inert gas is flowed upwardly through the tube. The tube may be constructed from two or more tube segments. The annealing device may include a plurality of tubes arranged and housed within a shell. The annealing device and method are suitable for a continuous process.

Abstract: This disclosure concerns embodiments of an annealing device and a method for annealing granular silicon to reduce a hydrogen content of the granular silicon. The annealing device comprises at least one tube through which granular silicon is flowed downwardly. The tube includes a heating zone and (i) a residence zone below the heating zone, (ii) a cooling zone below the heating zone, or (iii) a residence zone below the heating zone and a cooling zone below the residence zone. An inert gas is flowed upwardly through the tube. The tube may be constructed from two or more tube segments. The annealing device may include a plurality of tubes arranged in parallel and housed within a shell. The annealing device and method are suitable for a continuous process.

Abstract: This disclosure concerns embodiments of an annealing device and a method for annealing granular silicon to reduce a hydrogen content of the granular silicon. The annealing device comprises at least one tube through which granular silicon is flowed downwardly. The tube includes a heating zone and (i) a residence zone below the heating zone, (ii) a cooling zone below the heating zone, or (iii) a residence zone below the heating zone and a cooling zone below the residence zone. An inert gas is flowed upwardly through the tube. The tube may be constructed from two or more tube segments. The annealing device may include a plurality of tubes arranged in parallel and housed within a shell. The annealing device and method are suitable for a continuous process.

Abstract: This disclosure concerns embodiments of an annealing device and a method for annealing flowable, finely divided solids, such as annealing granular silicon to reduce a hydrogen content of the granular silicon. The annealing device comprises at least one tube through which flowable, finely divided solids are flowed downwardly. The tube includes a heating zone and (i) a residence zone below the heating zone, (ii) a cooling zone below the heating zone, or (iii) a residence zone below the heating zone and a cooling zone below the residence zone. An inert gas is flowed upwardly through the tube. The tube may be constructed from two or more tube segments. The annealing device may include a plurality of tubes arranged and housed within a shell. The annealing device and method are suitable for a continuous process.

Abstract: This disclosure concerns embodiments of an annealing device and a method for annealing flowable, finely divided solids, such as annealing granular silicon to reduce a hydrogen content of the granular silicon. The annealing device comprises at least one tube through which flowable, finely divided solids are flowed downwardly. The tube includes a heating zone and (i) a residence zone below the heating zone, (ii) a cooling zone below the heating zone, or (iii) a residence zone below the heating zone and a cooling zone below the residence zone. An inert gas is flowed upwardly through the tube. The tube may be constructed from two or more tube segments. The annealing device may include a plurality of tubes arranged and housed within a shell. The annealing device and method are suitable for a continuous process.

Abstract: Segmented silicon carbide liners for use in a fluidized bed reactor for production of polysilicon-coated granulate material are disclosed, as well as methods of making and using the segmented silicon carbide liners. Non-contaminating bonding materials for joining silicon carbide segments also are disclosed. One or more of the silicon carbide segments may be constructed of reaction-bonded silicon carbide.

Abstract: Apparatus and methods for consolidating granular silicon and determining trace elements content of the consolidated silicon are disclosed. Silicon granules are placed in a vessel, and a silicon slug of known purity is embedded at least partially in the granules. The slug is preheated to a temperature sufficient to couple with an induction heater. As the silicon slug melts, silicon granules adjacent the molten silicon also melt. The vessel passes through an induction coil to successively inductively heat and melt regions of the silicon granules from the leading end to the trailing end with each region solidifying as the molten silicon exits the induction coil to provide a multicrystalline silicon ingot. The multicrystalline silicon ingot is sliced into wafers, which are analyzed by low-temperature Fourier transform infrared spectroscopy to determine levels of trace elements in the ingot.

Abstract: Embodiments of a method for reducing iron silicide and/or iron phosphide fouling and/or corrosion in a hydrochlorosilane production plant are disclosed. Sufficient trichlorosilane is included in a silicon tetrachloride process stream to minimize hydrogen chloride formation, thereby inhibiting iron (II) chloride formation and reducing iron silicide and/or iron phosphide fouling, superheater corrosion, or a combination thereof.

Abstract: Segmented silicon carbide liners for use in a fluidized bed reactor for production of polysilicon-coated granulate material are disclosed, as well as methods of making and using the segmented silicon carbide liners. Non-contaminating bonding materials for joining silicon carbide segments also are disclosed. One or more of the silicon carbide segments may be constructed of reaction-bonded silicon carbide.

Abstract: The present invention relates to methods for operating and controlling the temperature of inert electrodes during production of molten aluminum by electrolysis of an aluminous ore, preferably alumina, dissolved in molten salts, preferably a fluoride based electrolyte, in an electrolysis cell with vertical or essentially vertical electrode configuration. The invention describes methods of designing and operating inert electrodes in a vertical and/or inclined position for production of aluminum metal, where said electrodes have an operating temperature that may deviate from the electrolyte temperature, thereby controlling the dissolution of electrode materials and preventing solid deposit formation on the electrodes. The present invention is also applicable to aluminum production cells utilizing inert electrodes in a horizontal configuration, and traditional Hall-Hèroult cells retrofitted with inert anodes.

Abstract: Apparatus and methods for consolidating granular silicon and determining trace elements content of the consolidated silicon are disclosed. Silicon granules are placed in a vessel, and a silicon slug of known purity is embedded at least partially in the granules. The slug is preheated to a temperature sufficient to couple with an induction heater. As the silicon slug melts, silicon granules adjacent the molten silicon also melt. The vessel passes through an induction coil to successively inductively heat and melt regions of the silicon granules from the leading end to the trailing end with each region solidifying as the molten silicon exits the induction coil to provide a multicrystalline silicon ingot. The multicrystalline silicon ingot is sliced into wafers, which are analyzed by low-temperature Fourier transform infrared spectroscopy to determine levels of trace elements in the ingot.

Abstract: Methods for reducing iron silicide and/or iron phosphide fouling and/or corrosion in a hydrochlorosilane production plant are disclosed. Sufficient hydrogen is added to a silicon tetrachloride process stream to inhibit iron (II) chloride formation and reduce iron suicide and/or iron phosphide fouling, superheater corrosion, or a combination thereof. Trichlorosilane also may be added to the silicon tetrachloride process stream.

Abstract: The present invention relates to a method of improving the current efficiency (CE) in an electrolytic aluminum production cell with an electrolytic bath, at least one anode and at least one cathode, and passing current between said anode and said cathode through said bath and feeding an aluminum containing feedstock to the cell. The CE is improved in that the aluminum containing feedstock is prepared in a manner where it contains substantially no humidity or water before it is fed to the cell, where the electrolytic process is carried out at conditions with reduced amount of hydrogen present.

Abstract: This invention relates to a device and method for production of ingots of semiconductor grade silicon, including solar grade silicon, where the presence of oxygen in the hot zone is substantially reduced or eliminated by employing materials void of oxides in the hot zone of the melting and crystallisation process. The method may be employed for any known process including for ciystallising semiconductor grade silicon ingots, including solar grade silicon ingots, such as the Bridgman process, the block-casting process, and the CZ-process for growth of monocrystalline silicon crystals. The invention also relates to devices for carrying out the melting and crystallisation processes, where the materials of the hot zone are void of oxides.

Abstract: This invention relates to reusable crucibles for production of ingots of semiconductor grade silicon made of nitride bonded silicon nitride (NBSN). The crucibles may be made by mixing silicon nitride powder with silicon powder, forming a green body of the crucible, and then heating the green body in an atmosphere containing nitrogen such that the silicon powder is nitrided forming the NBSN-crucible. Alternatively the crucibles may assembled by plate elements of NBSN-material that are to be the bottom and walls of a square cross-section crucible, and optionally sealing the joints by applying a paste comprising silicon powder and optionally silicon nitride particles, followed by a second heat treatment in a nitrogen atmosphere.

Abstract: This invention relates to a method for direct solidification of semiconductor grade multi-crystalline silicon ingots allowing improved control with the solidification process and reduced levels of oxygen and carbon impurities in the ingot, by crystallizing the semiconductor grade silicon ingot, optionally also including the melting of the feed silicon material, in a crucible made of silicon nitride, or in a crucible made of a composite of silicon carbide and silicon nitride, and where the wall thickness of the bottom of the crucible is dimensioned such that the thermal resistance across the bottom is reduced to a level of at least the same order as thermal resistance across the support below carrying the crucible or lower.

Abstract: A method for electrolytic production of aluminium metal from an electrolytic (3) including aluminium oxide, by performing electrolysis, with at least one inert anode (1) and at least one cathode (2) thus forming part of an electorwinning cell. The anode evolves oxygen gas and the cathode has aluminium discharged onto it in the electrolysis process, where the oxygen gas enforces an electrolyte flow pattern. The oxygen gas is directed to flow into anode grooves and is drained away from the interpolar room, thereby establishing an electrolyte flow pattern between the electrodes (1) and (2) and between over the anodes (1). The invention also concerns and anode assembly and an electrowinning cell.

Abstract: An anode for the electrolysis of aluminium made from an outer dense layer of a ceramic material on a dense core made from a composite of the ceramic material of the outer layer and an electronic conductor.