CN114645135A - Metal material reduction method with small-diameter opening cavity and reduction furnace - Google Patents
Metal material reduction method with small-diameter opening cavity and reduction furnace Download PDFInfo
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- CN114645135A CN114645135A CN202210323560.5A CN202210323560A CN114645135A CN 114645135 A CN114645135 A CN 114645135A CN 202210323560 A CN202210323560 A CN 202210323560A CN 114645135 A CN114645135 A CN 114645135A
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- reduction
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- 230000009467 reduction Effects 0.000 title claims abstract description 47
- 238000000034 method Methods 0.000 title claims abstract description 40
- 239000007769 metal material Substances 0.000 title claims abstract description 26
- 239000007789 gas Substances 0.000 claims abstract description 58
- 230000029058 respiratory gaseous exchange Effects 0.000 claims abstract description 16
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 15
- 238000010438 heat treatment Methods 0.000 claims abstract description 15
- 239000001301 oxygen Substances 0.000 claims abstract description 15
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 15
- 238000007599 discharging Methods 0.000 claims abstract description 4
- 239000011261 inert gas Substances 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 abstract description 19
- 239000002184 metal Substances 0.000 abstract description 19
- 238000006722 reduction reaction Methods 0.000 description 38
- 239000000203 mixture Substances 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000005086 pumping Methods 0.000 description 4
- 238000011946 reduction process Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000000241 respiratory effect Effects 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/12—Dry methods smelting of sulfides or formation of mattes by gases
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D7/00—Forming, maintaining or circulating atmospheres in heating chambers
- F27D7/06—Forming or maintaining special atmospheres or vacuum within heating chambers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D7/00—Forming, maintaining or circulating atmospheres in heating chambers
- F27D7/06—Forming or maintaining special atmospheres or vacuum within heating chambers
- F27D2007/063—Special atmospheres, e.g. high pressure atmospheres
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Furnace Details (AREA)
Abstract
The embodiment of the application provides a metal material reduction method with a small-caliber opening cavity and a reduction furnace, and the method comprises the following steps: a heating step: heating the hearth to reach the necessary reduction temperature in the hearth; a breath replacement step: filling reducing gas into the airtight hearth by using a positive pressure reducing gas source until the pressure in the hearth reaches a first pressure; discharging the mixed gas until the pressure in the hearth is reduced to a second pressure; repeating the breathing replacement step until the oxygen content of the gas in the hearth reaches a target value. According to the embodiment of the application, the reduction of the oxygen content of the atmosphere in the hearth is realized through the breathing replacement step, and the hearth and the metal of the small-caliber cavity do not need to be pumped to negative pressure, so that vacuum generation equipment is not needed, the requirement on the air tightness of the hearth is not very high, and the dependence on the equipment and the equipment cost are reduced.
Description
Technical Field
The invention relates to a metal inner cavity reduction technology, in particular to a metal material reduction method with a small-caliber opening cavity and a reduction furnace.
Background
The gas phase reduction method is a method in which a reducing gas reduces a metal oxide in a high temperature environment. The reduction of metal compounds using a gas as a reducing agent is a common method for obtaining pure metals, and this method requires that the surface of the metal material to be reduced is in full contact with the reducing gas, and the reducing gas is continuously flowed on the surface of the metal material to be reduced to achieve the best continuous reduction effect. It is particularly difficult to reduce the metal material to be reduced inside the chamber by the gas phase reduction method if the metal material to be reduced contains a chamber structure and the chamber has only a small number of small-caliber openings.
At present, a gas phase reduction method widely used for reducing small-caliber metal inner cavities utilizes high-temperature vacuum reduction furnace equipment to carry out metal materials, and the method comprises the steps of putting the metal materials to be reduced into an airtight hearth of the high-temperature vacuum reduction furnace, then pumping air in the airtight hearth to a certain vacuum value through a vacuum generating device, continuously filling deoxidized reducing gas, and heating to the necessary reducing temperature to ensure that the metal materials to be reduced and the reducing gas are subjected to reduction reaction to obtain pure metal materials.
The method for reducing the small-caliber metal inner cavity by using the high-temperature vacuum reduction furnace equipment has the following defects:
firstly, the high-temperature vacuum reduction furnace is high in manufacturing cost. The high-temperature vacuum reduction furnace is expensive due to high-value components such as the vacuum generator and the related sensor and expensive maintenance cost.
Secondly, the high-temperature vacuum reduction furnace is used for replacing gas in the small-caliber metal inner cavity, and the whole air cannot be replaced thoroughly due to the limitation of the capacity of the vacuum generator device. The vacuum capacity of a common mechanical vacuum pump is 1-5 Pa, and only about 0.5-1 Pa can be achieved under the condition of serially connecting and increasing Roots pumps. This results in the possibility of repeated oxidation of the small-bore metal cavity, which significantly compromises the effect of gas phase reduction.
And thirdly, the high-temperature vacuum reduction furnace is used for replacing gas in the small-caliber metal inner cavity, and the replacement step is difficult to continue after the furnace temperature is increased to the necessary temperature for metal reduction, because the vacuum generating device cannot bear the continuous passing of high-temperature gas. Therefore, the reducing gas can not continuously flow on the surface of the metal material to be reduced, after the initial reducing gas reacts with the metal oxide to generate oxide gas, the reducing gas is consumed to reduce the concentration, and the continuous reaction of the metal surface of the small-caliber inner cavity and the reducing gas is blocked, so that the gas-phase reduction effect and efficiency are greatly reduced.
And fourthly, performing gas replacement on the small-caliber metal cavity by using the high-temperature vacuum reduction furnace, wherein when the initial air in the hearth cavity is extracted, the reduction of the vacuum degree is slowed along with the gradual reduction of the air density. As shown in FIG. 1 and FIG. 2, for example, a 400L space furnace chamber, it takes about 2 minutes for a general mechanical vacuum pump to a vacuum degree of 10Pa, about 8 minutes for pumping to 5Pa, and about 30 minutes for pumping to 1 Pa. The pumping needs to be repeated for several times to achieve lower oxygen content, and the efficiency is low.
Therefore, a new method for reducing a small-diameter metal cavity is urgently needed to solve the above problems.
Disclosure of Invention
The invention aims to provide a metal material reduction method with a small-caliber opening cavity and a reduction furnace, so as to improve the efficiency and reduce the equipment cost.
The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
According to an aspect of the present invention, there is provided a method for reducing a metal material with a small-bore open cavity, comprising:
a heating step: heating the hearth to reach the necessary reduction temperature in the hearth;
a breath replacement step: filling reducing gas into the airtight hearth by using a positive pressure reducing gas source until the pressure in the hearth reaches a first pressure; discharging the mixed gas until the pressure in the hearth is reduced to a second pressure;
repeating the breathing replacement step until the oxygen content of the gas in the hearth reaches a target value.
In one embodiment, the first pressure is not less than 1.5 times atmospheric pressure.
In one embodiment, the second pressure is less than the first pressure and not less than atmospheric pressure.
In one embodiment, the heating step is performed simultaneously with the respiratory replacement step.
In one embodiment, the breath replacement step is repeated 5 to 10 times.
In one embodiment, the breath replacement step is repeated 7 times.
In one embodiment, after the temperature in the furnace chamber reaches the necessary temperature for reduction, at least one more breathing replacement step is performed.
In one embodiment, the reducing gas is a mixture of a reducing gas and an inert gas.
In one embodiment, the output pressure of the positive pressure reducing gas source is 0.2MPa to 0.8 MPa.
According to a second aspect of the present invention, there is provided a reduction furnace for carrying out the method according to the first aspect, comprising a hearth, the hearth being provided with an inlet port and an outlet port, the inlet port being connected to a positive pressure reducing gas source, and the hearth being provided with a heating element.
The embodiment of the invention has the beneficial effects that: the reduction of the oxygen content of the atmosphere in the hearth is realized through the breathing replacement step, and the hearth and the metal of the small-caliber cavity do not need to be pumped to negative pressure, so that vacuum generation equipment is not needed, the requirement on the air tightness of the hearth is not very high, and the dependence on the equipment and the equipment cost are reduced.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
The above features and advantages of the present disclosure will be better understood upon reading the detailed description of embodiments of the disclosure in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components having similar relative characteristics or features may have the same or similar reference numerals.
FIG. 1 is a schematic diagram of the time required and the number of times required for a conventional high-temperature vacuum reduction furnace to reach a corresponding static pressure;
FIG. 2 is a table listing the time required and the number of changes required to achieve the corresponding static pressure in the conventional high temperature vacuum reduction furnace;
FIG. 3 is a schematic flow chart of an embodiment of the method of the present application;
FIG. 4 is a schematic representation of the number of changes required to achieve the corresponding oxygen levels in an example of the process of the present application;
FIG. 5 is a table listing the number of permutations required to achieve the corresponding oxygen levels for an example of the process of the present application.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments. It is noted that the aspects described below in connection with the figures and the specific embodiments are only exemplary and should not be construed as imposing any limitation on the scope of the present invention.
As shown in fig. 3, an embodiment of the present application provides a method for reducing a metal material with a small-caliber opening cavity, including:
a heating step: heating the hearth to reach the necessary reduction temperature in the hearth;
a breath replacement step: filling reducing gas into the airtight hearth by using a positive pressure reducing gas source until the pressure in the hearth reaches a first pressure; discharging the mixed gas until the pressure in the hearth is reduced to a second pressure;
repeating the breathing replacement step for a plurality of times until the oxygen content of the gas in the hearth reaches a target value.
Wherein, the breath replacement step is a process of gradually replacing the air in the hearth with a reducing atmosphere by utilizing inflation and exhaust circulation. The method utilizes the natural high positive pressure characteristic of the positive pressure reducing gas source, can conveniently and rapidly pressurize the hearth and the metal of the small-caliber cavity, and has high efficiency and high speed. Compared with the existing vacuum reduction method, the method has the advantages of simple and reliable equipment and operation method. Because the hearth and the small-caliber cavity metal do not need to be pumped to negative pressure, vacuum generation equipment is not needed, the requirement on the air tightness of the hearth is not high, and the dependence on the equipment and the equipment cost are reduced.
During the charging process, the first pressure in the furnace is related to the output pressure of the positive pressure reducing gas source, and in a possible embodiment, the first pressure is not less than 1.5 times the atmospheric pressure. The second pressure in the furnace during the exhaust is less than the first pressure and not less than atmospheric pressure (preferably the second pressure is equal to atmospheric pressure) to ensure that sufficient mixed gas (mixture of reducing gas and air) is exhausted.
The oxygen content of the general reduction process atmosphere is required to be less than or equal to 10PPM, and the oxygen content of the better reduction process atmosphere is required to be less than or equal to 1 PPM. As shown in FIG. 4 and FIG. 5, the breath replacement step is repeated 5-10 times to meet the oxygen content requirement of the general reduction process atmosphere. To achieve an oxygen content of less than or equal to 1PPM, the preferred number of respiratory replacement steps is 7.
In a possible embodiment, the output pressure of the positive pressure reducing gas source may be 0.2MPa to 0.8 MPa. Tests show that the oxygen content in the metal of the hearth and the small-caliber cavity can be reduced to below 1PPM by using a 0.4MPa reducing gas source for 8 times of breathing and replacement and taking 40 minutes. And (3) breathing and replacing for 8 times by using a 0.7MPa reducing gas source, and consuming 30 minutes to reduce the oxygen content in the metal of the hearth and the small-caliber cavity to below 1 PPM.
It should be noted that in the method, because the exhaust does not need to enter any component, the heating step and the breathing replacement step can be carried out simultaneously, so that the reducing gas can be well mixed and flow sufficiently in each breathing replacement, the reducing gas is in full contact with the surface of the metal to be reduced, and the metal reduction effect is ensured. Further, the breathing replacement step can be performed at least once more after the necessary temperature for reduction is reached in the furnace. The breathing replacement action can be carried out at any furnace temperature, so that the hearth can be heated and breathing and air exchange can be carried out at the same time, waiting time is not needed, the production efficiency is further improved, and compared with the traditional vacuum air extraction method, the efficiency is improved by about 500 percent.
The reducing gas can be a mixture of the reducing gas and inert gas according to a certain proportion. The reducing gas may be hydrogen, carbon monoxide, carbon dioxide, etc., and the inert gas may be nitrogen, argon, etc. For example, the reducing gas may be a mixture of 5% hydrogen and 95% nitrogen, or a mixture of 15% carbon monoxide and 85% argon.
It is easy to understand that the embodiment of the present application further provides a reduction furnace for implementing the above method, which includes a hearth, the hearth is provided with an air inlet and an air outlet, the air inlet is connected to a positive pressure reducing gas source, and a heating element (e.g., a resistance wire) is disposed in the hearth. Compared with the existing high-temperature vacuum furnace, the vacuum furnace has the advantages that a vacuum generator (a vacuum tube and the like) and a vacuum degree sensor are not required to be arranged, so that the equipment cost is reduced.
In summary, the method for reducing the metal material with the small-caliber opening cavity and the reduction furnace provided by the embodiment of the application are simple and reliable, have low equipment cost, and can efficiently reduce the metal material with the small-caliber opening cavity.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
The above description is only a preferred example of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.
Claims (10)
1. A metal material reduction method with a small-caliber opening cavity is characterized by comprising the following steps:
a heating step: heating the hearth to reach the necessary reduction temperature in the hearth;
a breath replacement step: filling reducing gas into the airtight hearth by using a positive pressure reducing gas source until the pressure in the hearth reaches a first pressure; discharging the mixed gas until the pressure in the hearth is reduced to a second pressure;
repeating the breathing replacement step until the oxygen content of the gas in the hearth reaches a target value.
2. The method for reducing a metallic material with a small-caliber open cavity as recited in claim 1, wherein the first pressure is not less than 1.5 times atmospheric pressure.
3. The method as claimed in claim 2, wherein the second pressure is lower than the first pressure and not lower than atmospheric pressure.
4. The method for reducing a metallic material with a small-bore open cavity according to claim 1, wherein the heating step is performed simultaneously with the breath replacement step.
5. The method for reducing a metal material with a small-caliber open cavity according to claim 1, wherein the breathing replacement step is repeated 5-10 times.
6. The method for reducing a metallic material with a small-bore open cavity according to claim 1, wherein the breath replacement step is repeated 7 times.
7. A method for reducing metallic materials with small-bore open cavity as in claim 1, wherein after the necessary temperature for reduction is reached in the furnace, at least one more breathing replacement step is performed.
8. The method for reducing a metallic material with a small-caliber open cavity as recited in claim 1, wherein the reducing gas is a mixed gas of a reducing gas and an inert gas.
9. The method for reducing a metal material with a small-caliber opening cavity as claimed in claim 1, wherein the output pressure of the positive pressure reducing gas source is 0.2MPa to 0.8 MPa.
10. A reduction furnace for implementing the method according to any one of claims 1 to 9, comprising a hearth, wherein the hearth is provided with an air inlet and an air outlet, the air inlet is connected with a positive pressure reducing gas source, and a heating element is arranged in the hearth.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210323560.5A CN114645135A (en) | 2022-03-30 | 2022-03-30 | Metal material reduction method with small-diameter opening cavity and reduction furnace |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210323560.5A CN114645135A (en) | 2022-03-30 | 2022-03-30 | Metal material reduction method with small-diameter opening cavity and reduction furnace |
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| CN202210323560.5A Pending CN114645135A (en) | 2022-03-30 | 2022-03-30 | Metal material reduction method with small-diameter opening cavity and reduction furnace |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN86104946A (en) * | 1986-08-04 | 1987-05-20 | 黔江机械厂劳动服务公司 | The circulating purification outside protection heating means of industrial furnace |
| US5261976A (en) * | 1991-12-31 | 1993-11-16 | Gas Research Institute | Control system for a soft vacuum furnace |
| CN1140490A (en) * | 1994-12-02 | 1997-01-15 | 川崎制铁株式会社 | Non-oxidizing heating method and apparatus therefor |
| JP2003064415A (en) * | 2001-08-23 | 2003-03-05 | Daido Steel Co Ltd | Adjustment of atmosphere and temperature of heat treatment furnace |
| CN108531731A (en) * | 2018-06-27 | 2018-09-14 | 孙院军 | A kind of bottom reduction apparatus and the restoring method using the device |
-
2022
- 2022-03-30 CN CN202210323560.5A patent/CN114645135A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN86104946A (en) * | 1986-08-04 | 1987-05-20 | 黔江机械厂劳动服务公司 | The circulating purification outside protection heating means of industrial furnace |
| US5261976A (en) * | 1991-12-31 | 1993-11-16 | Gas Research Institute | Control system for a soft vacuum furnace |
| CN1140490A (en) * | 1994-12-02 | 1997-01-15 | 川崎制铁株式会社 | Non-oxidizing heating method and apparatus therefor |
| JP2003064415A (en) * | 2001-08-23 | 2003-03-05 | Daido Steel Co Ltd | Adjustment of atmosphere and temperature of heat treatment furnace |
| CN108531731A (en) * | 2018-06-27 | 2018-09-14 | 孙院军 | A kind of bottom reduction apparatus and the restoring method using the device |
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