MXPA06015121A - Production of valve metal powders with improved physical and electrical properties - Google Patents
Production of valve metal powders with improved physical and electrical propertiesInfo
- Publication number
- MXPA06015121A MXPA06015121A MXPA/A/2006/015121A MXPA06015121A MXPA06015121A MX PA06015121 A MXPA06015121 A MX PA06015121A MX PA06015121 A MXPA06015121 A MX PA06015121A MX PA06015121 A MXPA06015121 A MX PA06015121A
- Authority
- MX
- Mexico
- Prior art keywords
- metal powder
- valve metal
- component
- valve
- particles
- Prior art date
Links
- 239000000843 powder Substances 0.000 title claims abstract description 165
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 164
- 239000002184 metal Substances 0.000 title claims abstract description 164
- 238000004519 manufacturing process Methods 0.000 title description 3
- 239000002245 particle Substances 0.000 claims abstract description 71
- 239000001301 oxygen Substances 0.000 claims abstract description 70
- MYMOFIZGZYHOMD-UHFFFAOYSA-N oxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims abstract description 70
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 70
- 238000000034 method Methods 0.000 claims abstract description 49
- 239000002923 metal particle Substances 0.000 claims abstract description 47
- FYYHWMGAXLPEAU-UHFFFAOYSA-N magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims abstract description 21
- 239000011777 magnesium Substances 0.000 claims abstract description 21
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 21
- 239000000203 mixture Substances 0.000 claims abstract description 17
- 230000003068 static Effects 0.000 claims abstract description 13
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminum Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 9
- OYPRJOBELJOOCE-UHFFFAOYSA-N calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 9
- 239000011575 calcium Substances 0.000 claims abstract description 9
- WHXSMMKQMYFTQS-UHFFFAOYSA-N lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 9
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 9
- 229910052788 barium Inorganic materials 0.000 claims abstract description 8
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium(0) Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000011261 inert gas Substances 0.000 claims description 8
- VBJZVLUMGGDVMO-UHFFFAOYSA-N Hafnium Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- 239000003990 capacitor Substances 0.000 claims description 4
- 229910052735 hafnium Inorganic materials 0.000 claims description 4
- 239000002253 acid Substances 0.000 claims description 3
- 229910001182 Mo alloy Inorganic materials 0.000 claims description 2
- 229910001257 Nb alloy Inorganic materials 0.000 claims description 2
- 229910001362 Ta alloys Inorganic materials 0.000 claims description 2
- 229910001069 Ti alloy Inorganic materials 0.000 claims description 2
- 229910001080 W alloy Inorganic materials 0.000 claims description 2
- 229910001093 Zr alloy Inorganic materials 0.000 claims description 2
- 229910045601 alloy Inorganic materials 0.000 claims description 2
- 239000000956 alloy Substances 0.000 claims description 2
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 238000001816 cooling Methods 0.000 claims description 2
- 239000000428 dust Substances 0.000 claims description 2
- 239000001307 helium Substances 0.000 claims description 2
- 229910052734 helium Inorganic materials 0.000 claims description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium(0) Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 2
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 239000011707 mineral Substances 0.000 claims description 2
- 239000011812 mixed powder Substances 0.000 claims description 2
- 238000002156 mixing Methods 0.000 claims description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 239000011733 molybdenum Substances 0.000 claims description 2
- 229910052754 neon Inorganic materials 0.000 claims description 2
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon(0) Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 claims description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 2
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 239000010955 niobium Substances 0.000 claims description 2
- 239000007787 solid Substances 0.000 claims description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 2
- 239000010936 titanium Substances 0.000 claims description 2
- 229910052719 titanium Inorganic materials 0.000 claims description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 2
- 229910052721 tungsten Inorganic materials 0.000 claims description 2
- 239000010937 tungsten Substances 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- 239000003638 reducing agent Substances 0.000 claims 1
- 238000007599 discharging Methods 0.000 description 2
- 238000001354 calcination Methods 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
Abstract
The invention relates to a process that involves (1) feeding (a) a first valve metal powder component containing valve metal particles and (b) reducing component into a reactor having a hot zone;and (2) subjecting the first valve metal powder component andthe reducing component to non-static conditions sufficient to simultaneously (i) agglomerate the first valve metal powder component particles, and (ii) reduce oxygen content in the valve metal powder component particles, and thereby form a second valve metal powder component containing oxygen-reduced valve metal particles, in which the reducing component is selected from the group consisting of magnesium reducing components, calcium reducing components, aluminum reducing components, lithium reducing components, barium reducing components, strontium, reducing components, and combinations thereof.
Description
PRODUCTION OF METAL POWDERS FOR VALVES WITH IMPROVED PHYSICAL AND ELECTRICAL PROPERTIES
BACKGROUND There has long been a need for the art of developing processes for preparing metal powders having improved surface areas, improved bulk densities, improved flowability and improved average particle diameters. Unfortunately, it has been discovered that processes such as those described in U.S. Patent No. 4,483,819 produce powders having the reduced surface area (capacitance) of the powders. It would be desirable to develop a process that overcomes the shortcomings of the known processes. SUMMARY OF THE INVENTION The invention relates to a process that involves (1) supplying (a) a first valve metal powder component (oxidizable metal) containing valve metal particles and (b) and reducing component in a reactor having a hot zone; and (2) subjecting the first valve metal powder component and the reducing component to sufficient non-static conditions to simultaneously (i) agglomerate the particles of the first valve metal powder component and (ii) reduce the oxygen content in the valves. particles of the valve metal powder component, and in this way form a second valve metal powder component containing valve metal particles with reduced oxygen content, wherein the reducing component is selected from the group of magnesium reducing components , calcium reducing components, aluminum reducing components, lithium reducing components, barium reducing components, strontium reducing components and combinations thereof. In one embodiment, the invention relates to the powder prepared according to said process. The invention also relates to a process involving (1) supplying (a) a first valve metal powder component containing valve metal particles having an oxygen content which is greater than about 1% by weight and (b) ) a reducing component in a reactor having a tube containing a hot zone having an angle ranging from about 0.1 to about 10 °, with respect to the horizontal axis of the tube; and (2) rotating, flipping and discharging the first valve metal powder component and the reducing component at a temperature that is at least about 670 ° C under continuous conditions sufficient to simultaneously (i) agglomerate the particles of the first powder component of metal valve, and (ii) reduce the oxygen content in the particles of the first valve metal powder component, and in this way form a second valve metal powder component containing valve metal particles with reduced oxygen content which have (i) a surface area that is at least approximately equal to or greater than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than the volumetric density of the particles of the first component of metal powder valve and (iii) a fluidity that is greater than that of the particles of the first valve metal powder. The reducing component is selected from the group of magnesium reducing components, calcium reducing components, aluminum reducing components, lithium reducing components, barium reducing components, strontium reducing components and combinations thereof. These and other features, aspects and advantages of the present invention will be better understood with reference to the following description and appended claims. DESCRIPTION The invention is based on the remarkable discovery that by using a valve metal powder component and a reducing component and subjecting them to non-static conditions, it is possible to obtain powders having improved properties, compared to powders prepared under static conditions. In general, the process of the invention (1) supplies (a) a first valve metal powder component containing metal valve particles and (b) a reducing component to a reactor having a hot zone; and (2) subject the first valve metal powder component and the reducing component to sufficient non-static conditions to simultaneously agglomerate (i) the particles of the first valve metal powder component, and (2) reduce the oxygen content in the valves. particles of metal valve powder component and thus form a second metal powder component valve containing metal valve particles with reduced oxygen content. The first valve metal powder component is selected from the group of hafnium acid, niobium, titanium, tantalum, zirconium, molybdenum, tungsten, hafnium alloys, niobium alloys, titanium alloys, tantalum alloys, zirconium alloys, alloys of molybdenum, tungsten alloys and combinations thereof. The reducing component is selected from the group of magnesium reducing components, calcium reducing components, aluminum reducing components,. lithium reducing components, barium reducing components, strontium reducing components and combinations thereof. In one embodiment, the reducing component is selected from the group of solid magnesium components, liquid magnesium, gaseous magnesium and combinations thereof. The reactor used for the practical realization of the process can be any reactor which when used according to the invention allows the production of powders having improved properties. In one embodiment, the reactor is a tube having at least one baffle wall to flip or mix the first valve metal powder component. The tube has a rotary speed that can vary. In one embodiment, the tube rotates at a speed ranging from about 0.25 rpm to about 10 rpm. Examples of suitable reactors that may be used include those reactors referred to as indirect heat rotary kilns or calcination furnaces, available from Harper International, HED International, Thermal Processing Solutions, Inc. The reducing component and the first valve metal powder component may be supplied to a reactor by any suitable means. In one embodiment, the reducing component and the first valve metal powder component are supplied to the reactor separately with two different supply tubes. In another embodiment, the first valve metal powder component and the reducing component are supplied to the reactor in a mixed powder component that is prepared by mixing the first valve metal component and the reducing component before supplying the reducing component and the first metal powder component to the reactor. The first valve metal powder component can be introduced to the reactor at various delivery rates. In one embodiment, the first valve metal powder component is introduced to the reactor at a flow rate ranging from about 1 to about 100 kg / hour and the tube has a diameter ranging from about 10 cm to about 200 cm. In one embodiment, the reducing component is a magnesium reducing component and the magnesium reducing component is introduced into the reactor, based on the oxygen content of the first valve metal powder component, with an excess of magnesium reducing component which varies from 0 to about 10% of the stoichiometric amount, so that (i) the flow rate varies from about 0.01 to about 10 kg / hour, (ii) the tube diameter varies from about 10 cm to about 200 cm and the reactor has a hot zone (or zones) with a length ranging from about 90 cm to about 3500 cm.
It is critical that the first valve metal powder be subjected to non-static conditions. The non-static conditions are selected among the group of dump discharge, rotation and combinations of the above.
The temperature at which the first metal powder valve and the second metal powder valve component are subjected may vary. In one embodiment, the first valve metal powder component and the second valve metal powder component are subjected to non-static conditions at a temperature ranging from about 670 ° C to about 1500 ° C. The valve metal particles with reduced oxygen content of the second metal valve powder component have useful properties. In one embodiment, the valve metal particles with reduced oxygen content of the second valve metal powder component have a fluidity that is at least about 0.5 grams / second. In another embodiment, the valve metal particles with reduced oxygen content of the second valve metal powder component have a fluidity ranging from about 0.2 grams / second to about 2.5 grams / second. In another embodiment, the valve metal particles with reduced oxygen content of the second valve metal powder component comprise particles having a fluidity ranging from about 20% to about 100%, or more, than the fluidity of the particles of the first component of metal powder valve. The volumetric density of the particles of the valve metal powders with reduced oxygen content of the second metal valve powder component may vary. In one embodiment, the valve metal particles with reduced oxygen content of the second valve metal powder component have a bulk density ranging from about 10 to about 100% or more of that of the valve metal particles of the first component of metal powder valve. The second valve metal powder component contains valve metal particles with reduced oxygen content that have a wide range of capacitances. In one embodiment, the second valve metal powder component contains valve metal particles with reduced oxygen content having a capacitance ranging from about 40 to about 200 μm -V / g. In one embodiment, the second valve metal powder component contains valve metal particles with reduced oxygen content having an oxygen: surface ratio ranging from about 0.25 to about 0.34 parts per million oxygen / per cm2. Advantageously, the surface area of the valve metal particles with reduced oxygen content of the second valve metal powder component is larger than the surface area of the valve metal particles of the first valve metal powder component. In one embodiment, the valve metal particles with reduced oxygen content have a surface area that is greater than about 50% of the surface area of the first valve metal powder component. In another embodiment, the valve metal particles with reduced oxygen content have a surface area ranging from about 10 to about 100% or more than the surface area of the particles of the first valve-metal powder component. The valve metal particles with reduced oxygen content have an oxygen content that is lower than the oxygen content of the starting powder. In general, valve metal particles with reduced oxygen content have an oxygen content that varies from 10%, 20%, 30%, 40% or more, less than the oxygen content of the first metal valve powder. In one embodiment, the valve metal particles with reduced oxygen content have an oxygen content ranging from about 30% to about 80% less than the content, oxygen of the first component of metal powder valve. In one embodiment, the valve metal particles with reduced oxygen content have a uniform particle distribution. In one embodiment, the second valve metal powder component contains valve metal particles with reduced oxygen content that satisfy one or more of the following conditions: (i) a surface area that is at least approximately equal to or greater than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than the volumetric density of the particles of the first valve metal powder component, (iii) a fluidity that is greater than that of the particles of the first metal powder valve, (iv) a mean particle diameter that is greater than the average particle diameter of the particles of the first valve metal powder component, compared to the drop in the surface area when the first powder component Metal valve is subjected to static conditions. In another embodiment, when the first valve metal powder component contains particles having an oxygen content that is greater than about 1% by weight, in one embodiment more than about 1.5% of the second metal powder component valve contains metal valve particles with reduced oxygen content that satisfies one or more of the following conditions: (i) a surface area that is less than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than the volumetric density of the particles of the first valve metal powder component, (iii) a fluidity that is greater than that of the first valve metal powder particles and (iv) a mean particle diameter that is greater than the average particle diameter of the first valve metal powder component. During use, the process of the invention is carried out in a wide range of conditions. For example, in one embodiment, the process is carried out in an inert gas selected from the group of argon, helium and neon so that the flow of the inert gas is in the same direction in which the first metal powder component is supplied. valve to the reactor. The inert gas has a flow that varies widely. In one embodiment, the flow rate ranges from about 0.05 to about 5 standard cubic feet / hour per square inch of tube diameter. In one embodiment, the pressure of the inert gas within the reactor should be in the range of about 1 to about 10 inches of water column. In a preferred embodiment, the process involves (1) supplying (a) a first valve metal powder component containing valve metal particles having an oxygen content that is greater than about 1% by weight and (b) a reducing component in a reactor having a tube containing a hot zone and having an angle varying from about 0.1 to about 10 °, with respect to the horizontal axis of the tube; and (2) rotating, flipping and unloading the first valve metal powder component and the reducing component at a temperature of at least about 670 ° C under continuous conditions sufficient to simultaneously (i) agglomerate the particles of the first metal powder component valve and (ii) produce the oxygen content in the particles of the first valve metal powder component. The process thus forms a second valve metal powder component containing valve metal particles with reduced oxygen content having (i) a surface area that is at least approximately equal to or greater than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than the volumetric density of the particles of the first valve metal powder component, and (iii) a fluidity that is greater than that of the first powder particles of the valve. metal valve, so that the reducing component is selected from the group of magnesium reducing components calcium reducing components, aluminum reducing components, lithium reducing components, barium reducing components and strontium reducing components and combinations thereof. The powders prepared according to the invention can be used for various purposes. In one embodiment, the powders are used to prepare capacitors. Said capacitor may involve a capacitor that includes a second sintered valve metal powder component in which the powder is prepared by a process that (a) supplies (1) a first valve metal powder component containing valve metal particles that they have an oxygen content that is greater than about 1% by weight and (2) a reducing component in a reactor having a tube containing a hot zone and having an angle ranging from about 0.1 to about 10 °. , with respect to the horizontal axis of the tube; and (b) rotating, flipping and unloading the first valve metal powder component and the reducing component at a temperature that is at least about 670 ° C under continuous conditions sufficient to simultaneously (i) agglomerate the valve metal particles of the first component valve metal and (ii) reduce the oxygen content in the particles of the first valve metal powder component and in this way form a second valve metal powder component containing valve metal particles with reduced oxygen content so that the valve metal particles with reduced oxygen content have (i) a surface area that is at least approximately equal to or greater than the surface area of the particles of the first valve metal powder component; (ii) a volumetric density that is greater than the volumetric density of the particles of the first valve metal powder component and (iii) a fluidity that is greater than the first metal powder particles; and wherein the reducing component is selected from the group of magnesium reducing components, calcium reducing components, aluminum reducing components, lithium reducing components, barium reducing components, strontium reducing components and combinations thereof. The process may contain additional stages. In one embodiment, the process further includes picking up the second valve metal powder component in a container, cooling the second valve metal powder component at room temperature and thereby subjecting the second valve metal powder component to passivation or exposure. The second component of metal dust valve cooled to the air, discharging the second component of metal powder valve and leaching the second component of metal powder valve into a solution of mineral acid. Although the present invention has been described in detail with reference to certain preferred versions thereof, other variations are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the versions contained therein.
Claims (31)
1. A process comprising: (1) supplying (a) a first valve metal powder component containing metal valve particles and (b) a reducing component to a reactor having a hot zone; (2) subjecting the first valve metal powder component and the reducing component to sufficient non-static conditions to simultaneously (i) agglomerate the particles of the first valve metal powder component and (ii) reduce the oxygen content in the particles of the valve. metal powder component valve, and in this way form a second valve metal powder component containing valve metal particles with reduced oxygen content, wherein the reducing component is selected from the group consisting of magnesium reducing components, components calcium reducers, aluminum reducing components, lithium reducing components, barium reducing components, strontium reducing components and combinations thereof.
2. The process of claim 1, wherein the second valve metal powder component contains valve metal particles with reduced oxygen content that satisfy one or more of the following conditions: (i) a surface area that is at least approximately equal or greater than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than the volumetric density of the particles of the first valve metal powder component, (iii) a fluidity that is greater than that of the particles of the first valve metal component, (iv) a mean particle diameter that is greater than the average particle diameter of the particles of the first valve metal powder component, compared to the drop in the surface area When the first component of metal powder valve is subjected to static conditions.
3. The process of claim 1, wherein the first valve metal powder component, contains particles having an oxygen content that is greater than about 1% by weight, or greater than about 1.5% by weight, Second component · metal powder valve contains metal valve particles with reduced oxygen content that satisfies one of the following conditions: (i) a surface area that is less than the surface area of the particles of the first component of metal powder valve , (ii) a volumetric density that is greater than the volumetric density of the particles of the first valve metal powder component, (iii) a fluidity that is greater than that of the valve metal powder particles, and (iv) a Average particle diameter that is greater than the average particle diameter of the first valve metal powder component.
4. The process of claim 1, wherein the non-static conditions are selected from the group consisting of tumbling, unloading, rotating and combinations of the foregoing.
5. The process of claim 1, wherein the reducing component and the first valve metal powder component are supplied to the reactor separately with two different supply tubes.
6. The process of claim 1, wherein the first valve metal powder component and the reducing component are supplied to the reactor in a mixed powder component that is prepared by mixing the first valve metal powder component and the reducing component before supply the reducing component and the first metal powder component valve to the reactor.
7. The process of claim 1, wherein the first valve metal powder component is selected from the group consisting of hafnium, niobium, titanium, tantalum, zirconium, molybdenum, tungsten, hafnium alloys, niobium alloys, titanium alloys. , tantalum alloys, zirconium alloys, molybdenum alloys, tungsten alloys and combinations thereof.
8. The process of claim 1, wherein the reducing component is selected from the group consisting of components of solid magnesium, liquid magnesium, gaseous magnesium and combinations thereof.
9. The process of claim 1 wherein the valve metal particles with reduced oxygen content of the second valve metal powder component have a fluidity that is at least about 0.5 grams / second, or about 0.2 grams / second to approximately 2.5 grams / second.
10. The process of claim 1, wherein the valve metal particles with reduced oxygen content of the second valve metal powder component comprise particles having a fluidity ranging from about 20% to about 100% greater than the fluidity of the particles of the first metal valve powder component.
11. The process of claim 1, wherein the valve metal particles with reduced oxygen content of the second valve metal powder component have a bulk density ranging from about 10 to about 100% greater than the metal valve particles of the first component of metal powder valve.
12. The process of claim 1, wherein the valve metal particles with reduced oxygen content have a surface area that is greater than about 50% of the surface area of the first valve metal powder component.
13. The process of claim 1, wherein the valve metal particles with reduced oxygen content have a surface area ranging from about 10 to about 150% greater than the surface area of the particles of the first metal powder component. valve .
14. The process of claim 1, wherein the reactor comprises a tube having at least one baffle wall to flip or mix the first valve metal powder component.
15. The process of claim 1, wherein the first valve metal powder component is introduced into the reactor at a flow rate ranging from about 1 to about 100 kg / h and the tube has a diameter ranging from about 10 cm to about 200 cm
16. The process of claim 1, wherein the reducing component is a magnesium reducing component and the magnesium reducing component is introduced into the reactor, based on the oxygen content of the first valve metal powder component, with an excess of magnesium reducing component ranging from 0 to about 10% of the stoichiometric amount, wherein (i) the flow rate varies from about 0.01 to about 10 kg / hour, (ii) the pipe diameter varies from about 10 cm to about 200 cm and the reactor has a hot zone with a length ranging from about 90 cm to about 3500 cm.
17. The process of claim 1, wherein the first valve metal powder component and the second valve metal powder component are subjected to non-static conditions at a temperature ranging from about 670 ° C to about 1500 ° C.
18. The process of claim 1, wherein the reactor is a tube that rotates at a speed ranging from about 0.25 rpm to about 10 rpm.
The process of claim 17, wherein the reactor is at an angle ranging from about 0.1 to about 10 °, relative to the horizontal axis of the tube.
20. The process of claim 1, wherein the reactor has a tube with a hot zone and the first valve metal powder component and the reducing component are maintained in the hot zone of the reactor for a residence time ranging from about 15 minutes. minutes at about 10 hours, at an angle ranging from about 0.1 to about 10 °, with respect to the horizontal axis of the tube and the reactor rotates at a speed ranging from about 0.25 rpm to about 10 rpm.
21. The process of claim 1, wherein the valve metal particles with reduced oxygen content have an oxygen content ranging from about 30% to about 80% less than the oxygen content of the first metal powder component. valve.
22. The process of claim 1, wherein the valve metal particles with reduced oxygen content have a uniform particle distribution.
23. The process of claim 1, wherein the process further comprises picking up the second valve metal powder component in a container, cooling the second valve metal powder component at room temperature and thereby subjecting the second powder component of the valve. metal valve to passivate or gradual exposure of the second metal powder component air-cooled valve, discharge the second component of metal powder valve, and leach the second component of metal powder valve into a mineral acid solution.
24. The process of claim 1, wherein the second valve metal powder component contains valve metal particles with reduced oxygen content having a capacitance ranging from about 40 to about 200 μm -V / g.
25. The process of claim 1, wherein the second valve metal powder component contains valve metal particles with reduced oxygen content having an oxygen: surface ratio ranging from about 0.25 to about 0.34 parts per million of oxygen / per cm.
26. The process of claim 1, wherein the process is carried out in an inert gas selected from the group consisting of argon, helium and neon and the flow of inert gas is in the same direction in which the first powder component is supplied. from metal valve to the reactor.
27. The process of claim 26, wherein the inert gas has a flow rate ranging from about 0.05 to about 5 standard cubic feet / hour per square inch of pipe diameter and the pressure of the inert gas within the reactor varies from about 1 to approximately 10 inches of water column.
28. The powder prepared according to claim 1.
29. A process comprising: (1) supplying (a) a first valve metal powder component containing valve metal particles having an oxygen content that is greater than about 1% by weight and (b) a reducing component in a reactor having a tube containing a hot zone having an angle ranging from about 0.1 to about 10 °, relative to the horizontal axis of the tube; and (2) rotating, flipping and unloading the first valve metal powder component and the reducing component at a temperature that is at least about 670 ° C under continuous conditions sufficient to simultaneously (i) agglomerate the particles of the first powder component of metal valve, and (ii) reduce the oxygen content in the particles of the first valve metal powder component, and in this way form a second valve metal powder component containing valve metal particles with reduced oxygen content that have (i) a surface area that is at least approximately equal to or greater than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than the volumetric density of the particles of the first component of metal powder valve and (iii) a fluidity that is greater than that of the first metal dust particles valve. wherein the reducing component is selected from the group consisting of magnesium reducing components, calcium reducing components, aluminum reducing components, lithium reducing components, barium reducing components, strontium reducing components and combinations thereof.
30. The powder prepared according to the process of claim 29.
31. A capacitor comprising a second sintered valve metal powder component in which the powder is prepared by a process comprising: (a) supplying (1) supplying a first valve metal powder component containing valve metal particles having an oxygen content that is greater than about 1% by weight and (2) a reducing component in a reactor having a tube containing a hot zone having an angle ranging from about 0.1 to about 10 °, to the horizontal axis of the tube; and (b) turning, flipping and unloading the first metal powder component valve and the reducing component at a temperature which is -at least about 670 ° C under continuous conditions sufficient to simultaneously (i) agglomerate the valve metal particles of the first valve metal component, and (ii) reduce the oxygen content in the particles of the first valve metal powder component, and in this way form a second valve metal powder component containing valve metal particles with reduced oxygen content , wherein the valve metal particles with reduced oxygen content have (i) a surface area that is at least approximately equal to or greater than the surface area of the particles of the first valve metal powder component, (ii) a volumetric density that is greater than that of the particles of the first valve metal powder component and (iii) a fluidity that is greater than that of the particles of the first valve metal powder; wherein the reducing component is selected from the group consisting of magnesium reducing components, calcium reducing components, aluminum reducing components, lithium reducing components, reducing components. ary, strontium reducing components and combinations thereof.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US60/582,579 | 2004-06-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| MXPA06015121A true MXPA06015121A (en) | 2008-10-03 |
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