A method for preparing tantalum and/or niobium powder for powder metallurgy comprises the following steps: (1) heat treatment sintering: the raw material tantalum and/or niobium powder is heat treated and sintered, and the sintered block is obtained by cooling and passivation after sintering; (2) Hydrogenation pulverization: the sintered block obtained by heat treatment is hydrogenated and pulverized to obtain hydrogenated tantalum and/or niobium powder; (3) deoxygenation: hydrogenated tantalum and/or niobium powder is added to the reducing metal for dehydrogenation and deoxygenation heat treatment to obtain a mixture of reducing metal oxides, residual reducing metals, dehydrogenated and deoxygenated tantalum and/or niobium powder; And (4) pickling for impurity removal: the mixture obtained after dehydrogenation and deoxygenation is pickled and dried to obtain tantalum and/or niobium powder suitable for powder metallurgy. The method is suitable for recovering and treating waste tantalum and/or niobium powder produced in the production process of high specific volume tantalum and/or niobium powder for capacitors, so as to prepare tantalum and/or niobium powder suitable for powder metallurgy, and requires small equipment investment, strong adaptability to raw materials, short process flow, and high safety factor in the treatment process.
Tantalum and niobium are rare elements and their properties are very similar. Since the oxide films of tantalum and niobium have very high dielectric constants, they are widely used in the manufacture of tantalum and/or niobium electrolytic capacitors. In addition, tantalum and/or niobium are also used in aerospace, defense, high-temperature vacuum furnaces heating components, boats and insulation materials because of their high melting point and low vapor pressure. In addition, tantalum and/or niobium have excellent corrosion resistance to liquid metals and strong acids other than hydrofluoric acid, and have good thermal conductivity and chemical stability, and are also used in chemical and metallurgical fields of anti-corrosion materials. In addition, because of their good biocompatibility, tantalum and/or niobium are often used in the medical field as surgical sutures, custom prosthetics, interbody fusion devices, artificial joints, bone injury repair materials, etc. Tantalum has a strong resistance to electronic stress migration, so it can also be used to make a barrier layer between copper wire and silicon in integrated circuits.
When tantalum and/or niobium are used to make electrolytic capacitors, a porous anode block is usually prepared using tantalum and/or niobium raw materials in powder form, and a tantalum wire and niobium wire is also inserted as the lead when the anode block is made, and tantalum sheet or niobium sheet is often used to process the capacitor shell. In other applications, in most cases tantalum and/or niobium powder is first pressed into rods or strips, then sintered, or even further electron beam melting or arc melting in order to achieve densification and high purification; This is followed by rolling, drawing and other processing to form rods, plates, sheets, tubes, wires, foils and other tantalum and/or niobium products.
