Process for preparing Nb and/or Ta powder

Abstract

The present invention relates to the production method of niobium powder and / or tantalum powder; The method is carried out by reducing oxygen-containing alkali metal fluoroniobate and / or oxygen-containing fluorotantalate, wherein the reduction reaction temperature is 300-1050 °C, using at least one alkali metal plus at least one halide selected from Mg, Ca, Sr, Ba, Ce and the oxygen-containing alkali metal fluoroniobate and / or oxygen-containing fluorotantalate Reaction takes place to produce niobium powder and / or tantalum powder; the reduction recovery rate is high during niobium powder and tantalum powder produced according to the inventive method, and the produced niobium powder and tantalum powder have large specific surface area, large porosity, and higher oxygen content Low, when used to make capacitor anodes, it has the characteristics of large open porosity, low leakage current and high specific volume; the invention is convenient for industrial production.

Description

technical field

[0001] The present invention relates to a process for the production of niobium and / or tantalum powder. Background technique

[0002] Niobium and tantalum, known as valve metals, have similar properties and can be used to manufacture the anode of electrolytic capacitors, that is, niobium wire or tantalum wire is embedded in niobium powder or tantalum powder, pressed into shape, sintered into a porous sintered body, and then in the electrolyte Anodic oxidation is carried out in the solution, and a dielectric oxide film is formed on the surface of the porous sintered body. On the oxide film, manganese dioxide or a conductive organic polymer solid electrolyte is sequentially formed to form a carbon layer and a silver layer as the cathode of the capacitor. The anode terminal and the cathode terminal are then resin-encapsulated to obtain a niobium / tantalum solid electrolytic capacitor.

[0003] As the niobium powder or tantalum powder of the electrolytic capacito...

Examples

Embodiment 1

[0046] 15 kg of potassium fluorooxyniobate (containing 1.02 kg of Nb 2 o 5 ) niobium raw material, with 25 kg of NaCl, 15 kg of KCl, 12 kg of CaCl 2 Put it into a closed reaction vessel with a stirring blade and a heat-resistant alloy lining inside with an inert gas inlet and outlet, heat it to 700°C under an argon atmosphere, inject 6,500 grams of liquid metal sodium, and make it undergo a reduction reaction, and then Heat up to 800°C for 1 hour. After cooling to room temperature, the reaction materials are stripped out, washed with water and pickled, and then dried to obtain 4107 grams of niobium powder. The BET specific surface area of ​​the original powder is 6.56m 2 / g, the oxygen content of the original powder of niobium powder is 9800ppm. attached figure 1 It is the scanning electron micrograph of the microstructure of this niobium powder. It can be seen that the niobium powder particles are porous aggregates with large specific surface area composed of many primary ...

Embodiment 2

[0059] The niobium raw material of 29 kg of potassium oxyfluoroniobate containing 1.03 kg of niobium oxide was mixed with 25 kg of NaCl and 2 kg of CaCl 2 , 40 kilograms of KCl are injected 11750 grams of liquid metal sodium at 800 ℃ according to the same method of embodiment 1, and other production processes are all identical with embodiment 1. Obtain 8350 grams of niobium powder, the BET specific surface area of ​​the former powder is 6.41m 2 / g, the oxygen content of the original powder of niobium powder is 11000ppm. The reduction recovery of niobium powder is shown in Table 1.

[0060] The raw niobium powder obtained above was subjected to doping, deoxidation and thermal agglomeration treatment in the same manner as in Example 1 to obtain agglomerated niobium powder.

[0061] The main chemical impurity content of niobium powder is shown in Table 2, and the physical properties are shown in Table 3. The porosity of agglomerated niobium powder is 88.99%.

[0062] Using th...

Embodiment 3

[0064] Mix the tantalum raw material containing 2.10 kg of tantalum oxide and 30 kg of potassium fluorotantalate with 65 kg of NaCl, 20 kg of KCl, and 8.0 kg of MgCl 2 Put it into a closed reaction vessel lined with a heat-resistant alloy with a stirring blade and an inert gas inlet and outlet. Heating to 800°C under an argon atmosphere, injecting 10,500 grams of liquid metal sodium to cause a reduction reaction, then raising the temperature, keeping it at 850°C for 1 hour, cooling to room temperature, stripping off the reaction material, washing with water, pickling, and then drying Dry, obtain tantalum powder 14094 grams, the BET specific surface area of ​​former powder is 3.86m 2 / g, its oxygen content is 7800ppm. The reduction recovery rate of tantalum powder is shown in Table 1.

[0065] The raw tantalum powder obtained above is doped, deoxidized and thermally agglomerated according to existing methods to obtain agglomerated tantalum powder.

[0066] The main chemical ...

technical field

[0001] The present invention relates to a process for the production of niobium and / or tantalum powder. Background technique

[0002] Niobium and tantalum, known as valve metals, have similar properties and can be used to manufacture the anode of electrolytic capacitors, that is, niobium wire or tantalum wire is embedded in niobium powder or tantalum powder, pressed into shape, sintered into a porous sintered body, and then in the electrolyte Anodic oxidation is carried out in the solution, and a dielectric oxide film is formed on the surface of the porous sintered body. On the oxide film, manganese dioxide or a conductive organic polymer solid electrolyte is sequentially formed to form a carbon layer and a silver layer as the cathode of the capacitor. The anode terminal and the cathode terminal are then resin-encapsulated to obtain a niobium / tantalum solid electrolytic capacitor.

[0003] As the niobium powder or tantalum powder of the electrolytic capacito...

Examples

Embodiment 1

[0046] 15 kg of potassium fluorooxyniobate (containing 1.02 kg of Nb 2 o 5 ) niobium raw material, with 25 kg of NaCl, 15 kg of KCl, 12 kg of CaCl 2 Put it into a closed reaction vessel with a stirring blade and a heat-resistant alloy lining inside with an inert gas inlet and outlet, heat it to 700°C under an argon atmosphere, inject 6,500 grams of liquid metal sodium, and make it undergo a reduction reaction, and then Heat up to 800°C for 1 hour. After cooling to room temperature, the reaction materials are stripped out, washed with water and pickled, and then dried to obtain 4107 grams of niobium powder. The BET specific surface area of ​​the original powder is 6.56m 2 / g, the oxygen content of the original powder of niobium powder is 9800ppm. attached figure 1 It is the scanning electron micrograph of the microstructure of this niobium powder. It can be seen that the niobium powder particles are porous aggregates with large specific surface area composed of many primary ...

Embodiment 2

[0059] The niobium raw material of 29 kg of potassium oxyfluoroniobate containing 1.03 kg of niobium oxide was mixed with 25 kg of NaCl and 2 kg of CaCl 2 , 40 kilograms of KCl are injected 11750 grams of liquid metal sodium at 800 ℃ according to the same method of embodiment 1, and other production processes are all identical with embodiment 1. Obtain 8350 grams of niobium powder, the BET specific surface area of ​​the former powder is 6.41m 2 / g, the oxygen content of the original powder of niobium powder is 11000ppm. The reduction recovery of niobium powder is shown in Table 1.

[0060] The raw niobium powder obtained above was subjected to doping, deoxidation and thermal agglomeration treatment in the same manner as in Example 1 to obtain agglomerated niobium powder.

[0061] The main chemical impurity content of niobium powder is shown in Table 2, and the physical properties are shown in Table 3. The porosity of agglomerated niobium powder is 88.99%.

[0062] Using th...

Embodiment 3

[0064] Mix the tantalum raw material containing 2.10 kg of tantalum oxide and 30 kg of potassium fluorotantalate with 65 kg of NaCl, 20 kg of KCl, and 8.0 kg of MgCl 2 Put it into a closed reaction vessel lined with a heat-resistant alloy with a stirring blade and an inert gas inlet and outlet. Heating to 800°C under an argon atmosphere, injecting 10,500 grams of liquid metal sodium to cause a reduction reaction, then raising the temperature, keeping it at 850°C for 1 hour, cooling to room temperature, stripping off the reaction material, washing with water, pickling, and then drying Dry, obtain tantalum powder 14094 grams, the BET specific surface area of ​​former powder is 3.86m 2 / g, its oxygen content is 7800ppm. The reduction recovery rate of tantalum powder is shown in Table 1.

[0065] The raw tantalum powder obtained above is doped, deoxidized and thermally agglomerated according to existing methods to obtain agglomerated tantalum powder.

[0066] The main chemical ...

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