Method for producing pure monocarbides, mononitrides and carbonitrides
AssigneeGesellschaft fur Kernforschung m.b.H.
InventorHorst Wedemeyer
Life of this patent
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Abstract
Pure monocarbides, or pure mononitrides or carbonitrides of metals are prepared by first forming a mixture of carbon with an oxalate of the metals and thermally decomposing the metal oxalate in the presence of the carbon by a stream of hydrogen. The hydrogen is removed and monocarbides are then formed by heating the decomposition products in vacuo to carbothermally reduce them. Mononitrides and carbonitrides can be formed by replacing the hydrogen with nitrogen and heating the decomposition products in the nitrogen.
Claims39
A method of producing pure monocarbides of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, thorium, uranium, plutonium, or americium comprising:
- a. forming a mixture of carbon with an oxalate of at least one of said metals;
- b. decomposing the metal oxalate in the presence of carbon in a stream of a hydrogen containing gas with addition of heat;
- c. removing the hydrogen containing gas;
- and
- d. heating the decomposition products immediately after removal of the hydrogen containing gas to an elevated temperature in vacuo to carbothermally reduce the decomposition products and from the monocarbide.
A method for producing pure mononitrides or carbonitrides of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, thorium, uranium, plutonium, or americium, comprising:
- a. forming a mixture of carbon with an oxalate of at least one of said metals;
- b. decomposing the metal oxalate in the presence of carbon in a stream of a hydrogen containing gas with the addition of heat;
- c. removing the hydrogen containing gas and feeding a nitrogen stream into contact with the decomposition products;
- and
- d. heating the decomposition products immediately after removal of the hydrogen containing gas in the nitrogen stream.
A method for producing pure monocarbides of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, thorium, uranium, plutonium, or americium, comprising:
- a. converting at least one of the metals to its oxalate;
- b. cleaning the oxalate;
- c. forming a homogeneous mixture of the oxalate with carbon;
- d. decomposing the oxalate in the presence of carbon in a stream of hydrogen or in a stream of a mixture of hydrogen and an inert gas with the addition of heat;
- e. removing the hydrogen containing stream;
- and
- f. heating the decomposition products in vacuo in a multi-stage heat treatment immediately after removal of the hydrogen containing stream to carbothermally reduce the decomposition products and form the monocarbide.
A method for producing pure mononitrides or carbonitrides of at least one of the metals titanium, vanadium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, thorium, uranium, plutonium or americium comprising:
- a. converting at least one of the metals to its oxalate;
- b. cleaning the oxalate;
- c. forming a homogeneous mixture of the oxalate with carbon;
- d. decomposing the oxalate in the presence of carbon in a stream of hydrogen or in a stream of hydrogen and an inert gas with the addition of heat;
- e. removing the hydrogen containing stream;
- and
- f. heating the decomposition products immediately after removal of the hydrogen containing stream in the stream of nitrogen in a multi-stage heat treatment.
Dependencies are inferred from the claim text.