Abstract: The present heat-resistant tungsten alloy has a first phase containing W as a major component, a second phase having a carbonitride of at least one element of Ti, Zr and Hf and containing the carbonitride as a major component when W is removed, and a third phase having a carbide of at least one element of group 5A elements in the periodic table and containing the carbide as a major component when W is removed, the heat-resistant tungsten alloy having a Vickers hardness of 550 Hv or more at a room temperature, a displacement of 1 mm or more when leading to fracture, as determined in a three point bending test at 1200° C., and a 0.2% proof stress of 900 MPa or more, as determined in the three point bending test at 1200° C.

Abstract: A heat-resistant molybdenum alloy of this invention comprises a first phase containing Mo as a main component and a second phase comprising a Mo—Si—B-based intermetallic compound particle phase, wherein the balance is an inevitable impurity and wherein the Si content is 0.05 mass % or more and 0.80 mass % or less and the B content is 0.04 mass % or more and 0.60 mass % or less.

Abstract: A heat-resistant member comprising a molybdenum alloy that comprises a first phase containing Mo as a main component and a second phase comprising a Mo—Si—B-based intermetallic compound particle phase, wherein the balance is an inevitable impurity and wherein the Si content is 0.05 mass % or more and 0.80 mass % or less and the B content is 0.04 mass % or more and 0.60 mass % or less. The member may be coated.

Abstract: A method of producing sodium tungstate of this invention including allowing cemented carbide scrap containing tungsten to react with a molten salt containing sodium sulfate and having added thereto a metal oxide, to thereby obtain sodium tungstate.

Abstract: A heat-resistant alloy that satisfies physical properties such as proof stress and hardness adapted to an increase in the melting point of a welding object compared to conventional alloys is provided. The heat resistant alloy includes a first phase, as a main component, containing a Mo or W metal phase, a second phase containing a Mo—Si—B—based alloy, and a third phase containing titanium carbonitride, wherein the balance is inevitable compounds and inevitable impurities.

Abstract: A Mo—Si—B-based alloy for a heat-resistant alloy that satisfies, more than conventional, physical properties such as proof stress and hardness adapted to an increase in the melting point of 5 a welding object. The Mo—Si—B-based alloy powder is such that the full width at half maximum of (600) of Mo5SiB2 in X-ray diffraction peak data is 0.08 degrees or more and 0.7 degrees or less.

Abstract: The present heat-resistant tungsten alloy has a first phase containing W as a major component, a second phase having a carbonitride of at least one element of Ti, Zr and Hf and containing the carbonitride as a major component when W is removed, and a third phase having a carbide of at least one element of group 5A elements in the periodic table and containing the carbide as a major component when W is removed, the heat-resistant tungsten alloy having a Vickers hardness of 550 Hv or more at a room temperature, a displacement of 1 mm or more when leading to fracture, as determined in a three point bending test at 1200° C., and a 0.2% proof stress of 900 MPa or more, as determined in the three point bending test at 1200° C.

Abstract: The purpose of the present invention is to provide a solution for use in the extraction of cobalt, whereby it becomes possible to extract cobalt at lower cost and more safely compared with a case in which a conventional one is used. The solution for use in the extraction of cobalt according to the present invention comprises: an ionic liquid containing a quaternary ammonium group; and an organic solvent which exists in such a state that the organic solvent is mixed with the ionic liquid and which has a kauri-butanol value of 60 or more.

Abstract: Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method.

Abstract: Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method.

Abstract: A method of producing sodium tungstate of this invention including allowing cemented carbide scrap containing tungsten to react with a molten salt containing sodium sulfate and having added thereto a metal oxide, to thereby obtain sodium tungstate.

Abstract: The present invention provides a composite material that is excellent in the bonding ability between a cemented carbide layer and a cermet layer is excellent and deformation after sintering can be suppressed and a coated cutting tool having a base containing the composite material. A composite material 10ii is obtained by laminating a cemented carbide layer 11 and a cermet layer 12 and has the cemented carbide layer 11 on the surface side. The boundary between both the layers 11 and 12 has a concave portion 23, and the maximum depth Dmax of the concave portion 23 is 50 ?m or more and 500 ?m or lower. When the thickness of the composite material is defined as h1 and the thickness of the cemented carbide layer 11 is defined as h2, h2/h1 is in the range of more than 0.02 and 0.4 or lower. By providing the concave portion 23 to the boundary, both the layers 11 and 12 are sufficiently bound and the bonding ability therebetween is excellent.

Abstract: A method for producing an ammonium tungstate aqueous solution includes the steps of: adding sulfuric acid to a solution containing tungstate ions; bringing the solution having the sulfuric acid added therein, into contact with an anion exchange resin; and bringing the anion exchange resin into contact with an aqueous solution containing ammonium ions.

Abstract: A heat-resistant member comprising a molybdenum alloy that comprises a first phase containing Mo as a main component and a second phase comprising a Mo—Si—B-based intermetallic compound particle phase, wherein the balance is an inevitable impurity and wherein the Si content is 0.05 mass % or more and 0.80 mass % or less and the B content is 0.04 mass % or more and 0.60 mass % or less. The member may be coated.

Abstract: There is provided a joined product suitable as a cutting tool that is fit for high-speed cutting, CVD coating process and the like, and does not cause a reduction in joint strength of a joining layer even if a high temperature exceeding a temperature at which a brazing filler forms the liquid phase is reached during cutting. Specifically, the joined product includes a cemented carbide sintered compact serving as a first material to be joined and a cBN sintered compact or a diamond sintered compact serving as a second material to be joined. The first material to be joined and the second material to be joined are joined by a joining material that does not form a liquid phase at a temperature lower than 1000° C. and that is placed between the first material to be joined and the second material to be joined. The joining is performed by resistance heating and pressing at a pressure of 0.1 to 200 MPa.

Abstract: Provided is a Mo—Si—B-based alloy for a heat-resistant alloy that satisfies, more than conventional, physical properties such as proof stress and hardness adapted to an increase in the melting point of a welding object. A Mo—Si—B-based alloy powder of this invention is such that the full width at half maximum of (600) of Mo5SiB2 in X-ray diffraction peak data is 0.08 degrees or more and 0.7 degrees or less.

Abstract: Provided is a heat-resistant alloy that satisfies physical properties such as proof stress and hardness adapted to an increase in the melting point of a welding object compared to conventional alloys. A heat-resistant alloy of this invention includes a first phase, as a main component, containing a Mo or W metal phase, a second phase containing a Mo—Si—B-based alloy, and a third phase containing titanium carbonitride, wherein the balance is inevitable compounds and inevitable impurities.

Abstract: There are provided a cemented carbide high in thermal diffusivity and excellent in wear resistance, and a cutting tool including a base material formed of this cemented carbide. The cemented carbide is a WC based cemented carbide in which a hard phase mainly constituted of WC grains is bound by a binder phase mainly constituted of Co, and is used for a cutting tool. The binder phase is substantially constituted of Co, or Co and Ni. A total content of Co and Ni is not less than 4.5 mass % and not more than 15 mass %. In this cemented carbide, the WC grains have an average diameter of not less than 0.4 ?m and not more than 4 ?m.

Abstract: A heat-resistant molybdenum alloy of this invention comprises a first phase containing Mo as a main component and a second phase comprising a Mo—Si—B-based intermetallic compound particle phase, wherein the balance is an inevitable impurity and wherein the Si content is 0.05 mass % or more and 0.80 mass % or less and the B content is 0.04 mass % or more and 0.60 mass % or less.

Abstract: Provided are a method for producing sodium tungstate by supplying an oxidant made of sodium nitrate or sodium nitrite to bring a tungsten containing material and the oxidant into contact with each other in an atmosphere containing oxygen to thereby continuously produce a reaction product; a method for collecting tungsten using the method; and an apparatus for producing sodium tungstate. Also provided are a method for producing a sodium tungstate aqueous solution in which a reductant is introduced into a melt containing the above-described reaction product which is then dissolved in water; and a method for collecting tungsten using the method.