CN111924837A - Preparation method of high-purity graphite paper - Google Patents
Preparation method of high-purity graphite paper Download PDFInfo
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- CN111924837A CN111924837A CN202010857161.8A CN202010857161A CN111924837A CN 111924837 A CN111924837 A CN 111924837A CN 202010857161 A CN202010857161 A CN 202010857161A CN 111924837 A CN111924837 A CN 111924837A
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- graphite
- graphite powder
- furnace
- treatment
- temperature
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 150
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 77
- 239000010439 graphite Substances 0.000 title claims abstract description 77
- 238000002360 preparation method Methods 0.000 title claims abstract description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 38
- 238000000746 purification Methods 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 18
- 238000005406 washing Methods 0.000 claims abstract description 16
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 15
- 238000005096 rolling process Methods 0.000 claims abstract description 15
- 238000010306 acid treatment Methods 0.000 claims abstract description 10
- 238000001035 drying Methods 0.000 claims abstract description 5
- 239000007789 gas Substances 0.000 claims description 18
- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Substances OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 12
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical group OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 10
- 229910052736 halogen Inorganic materials 0.000 claims description 9
- 150000002367 halogens Chemical class 0.000 claims description 9
- 238000004321 preservation Methods 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 8
- 239000007800 oxidant agent Substances 0.000 claims description 8
- 230000001590 oxidative effect Effects 0.000 claims description 8
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 claims description 6
- 238000004140 cleaning Methods 0.000 claims description 4
- 239000011259 mixed solution Substances 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 239000002351 wastewater Substances 0.000 claims description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 3
- 239000000460 chlorine Substances 0.000 claims description 3
- 229910052801 chlorine Inorganic materials 0.000 claims description 3
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims description 3
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 238000005086 pumping Methods 0.000 claims description 3
- 239000012535 impurity Substances 0.000 abstract description 10
- 239000002994 raw material Substances 0.000 abstract description 4
- 150000002500 ions Chemical class 0.000 abstract description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 239000010453 quartz Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000009489 vacuum treatment Methods 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
- C01B32/215—Purification; Recovery or purification of graphite formed in iron making, e.g. kish graphite
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/20—Graphite
- C01B32/21—After-treatment
- C01B32/22—Intercalation
- C01B32/225—Expansion; Exfoliation
Abstract
The application provides a preparation method of high-purity graphite paper, which comprises the steps of sequentially carrying out high-temperature purification, acid treatment, water washing, drying treatment, expansion treatment and rolling treatment on graphite powder, and obtaining finished graphite paper after the rolling treatment is finished; in the method, the raw material graphite powder of the graphite paper is subjected to high-temperature purification treatment at the beginning, most of impurities in the graphite powder are removed, and pure water is used for washing instead, so that impurity ions in water can be effectively prevented from entering the graphite powder; the carbon content of the graphite paper prepared by the traditional method is 98 wt% or more, and the carbon content of the graphite paper can be increased to 99.8 wt% or more.
Description
Technical Field
The invention relates to the technical field of high-temperature application of carbon materials, in particular to a preparation method of high-purity graphite paper.
Background
Graphite paper (flexible graphite sheet) can be used in an inert gas atmosphere or vacuum environment at ultra-high temperature up to 3000 ℃ due to its extraordinary properties. The excellent thermal and electrical conductivity of graphite paper makes it suitable for use in various parts such as heat-insulating cylinders, heat-insulating materials, flexible layers, sealing materials, etc. in semiconductor manufacturing equipment. In the photovoltaic industry, the graphite paper can reduce the corrosion of the quartz crucible to the graphite crucible and effectively prolong the service life of the quartz crucible.
However, the conventional common graphite paper manufactured in the prior art has low purity, high impurity content of about 98 wt%, and poor use effect, and for example, in the photovoltaic industry, the common graphite paper is easy to corrode quartz crucibles, and causes production accidents such as silicon leakage and the like.
The high-temperature vacuum treatment can play a role in purifying carbon products and reducing impurities. The graphite paper is directly treated by adopting a high-temperature vacuum treatment method, although the graphite paper can be purified, the tightness of mechanical combination of the internal expanded graphite of the graphite paper can be damaged, and the graphite paper becomes brittle and is difficult to be practically applied. Therefore, it is necessary to explore a new method for preparing high-purity graphite paper.
Therefore, how to improve the preparation method of the graphite paper and improve the purity of the graphite paper is a technical problem which needs to be solved urgently by the technical personnel in the field.
Disclosure of Invention
The invention aims to provide a preparation method of high-purity graphite paper.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
a preparation method of high-purity graphite paper comprises the following steps of:
1) putting graphite powder into a graphite crucible;
2) putting a graphite crucible containing graphite powder into a vacuum furnace or a gas high-temperature furnace, vacuumizing the vacuum furnace or the gas high-temperature furnace and raising the temperature in the furnace for purification, wherein the heat preservation temperature in the purification process is 1900-2500 ℃, the heat preservation time is 1-7 h, the vacuum degree in the furnace is 0.1-1000 Pa, and furnace cooling is carried out after the heat preservation process is finished;
3) taking out the graphite crucible after furnace cooling is finished, and then pouring graphite powder in the graphite crucible into a container;
4) acid treatment: pouring a mixed solution of an oxidant and concentrated sulfuric acid into the container filled with the graphite powder after the step 3), and uniformly stirring;
5) washing with water: cleaning the graphite powder subjected to acid treatment in the step 4) with pure water until the pH value of wastewater generated after water washing reaches 6-7;
6) drying the graphite powder prepared after the water washing in the step 5) until the water content in the graphite powder is reduced to 25-35 wt%;
7) putting the dried graphite powder obtained in the step 6) into an expansion furnace for expansion treatment to obtain expanded graphite;
8) rolling: and (3) rolling the expanded graphite prepared in the step (7), and obtaining finished graphite paper after the rolling treatment is finished.
Preferably, in the step 1), the graphite powder is flake graphite powder, and the carbon content in the flake graphite powder is 99.5 wt% -99.9 wt%.
Preferably, in the step 2), after the vacuum pumping is finished, halogen gas is introduced into the vacuum furnace or the gas high-temperature furnace, and high-temperature purification treatment is performed in a halogen gas atmosphere, wherein the halogen gas is one, two or three of hydrogen chloride, freon and chlorine.
Preferably, in the step 4), the concentrated sulfuric acid is concentrated sulfuric acid with a mass fraction of 95% or 98%;
the oxidant is hydrogen peroxide and/or potassium dichromate.
Preferably, in step 7), the expansion treatment is instantaneous expansion at 900 ℃ to 1100 ℃.
The application obtains the following beneficial technical effects:
1. in the application, the crystalline flake graphite powder with the carbon content of 99.5-99.9 wt% is subjected to high-temperature purification treatment at the temperature of more than 2000 ℃ to form high-purity crystalline flake graphite powder with the carbon content of 99.995 wt% and more, the use of chemical reagents in the traditional crystalline flake graphite purification method is avoided in the high-temperature purification process, the damage of the chemical reagents to human bodies and the pollution to the environment are reduced, in addition, the carbon content requirement on the common crystalline flake graphite used as the raw material for preparing graphite paper is reduced in the high-temperature purification process, and the raw material application range is wider.
2. In this application, the running water of washing process in with the traditional approach changes pure water (pure water) into, in order to get rid of the graphite powder in the acid treatment accomplish the remaining acid of back, need carry out a lot of washing to the graphite powder, this process need use a large amount of water, because the content of impurity such as calcium in the used running water, magnesium is higher among the traditional approach, calcium in the running water, impurity such as magnesium can get into the graphite powder, lead to the impurity content in the graphite powder to rise, and this application changes into and uses pure water (pure water), because pure water (pure water) is the water after the purification, calcium in pure water (pure water), the content of impurity such as magnesium is lower, consequently this application uses pure water (pure water) can effectively avoid in impurity ion gets into the graphite powder.
3. In the prior art, the finished product of graphite paper prepared after rolling is directly purified at high temperature, although the graphite paper can be purified, the tightness of mechanical combination of internal expanded graphite of the graphite paper can be damaged, so that the graphite paper becomes brittle and is difficult to be industrially and practically applied; in the application, the raw material graphite powder of the graphite paper is subjected to high-temperature purification treatment at first, the carbon content in the graphite powder is increased from 99.5 wt% -99.9 wt% to about 99.995 wt%, most impurities in the graphite powder are volatilized and removed in a gaseous state, the graphite paper with higher purity can be finally obtained, and the situation that the graphite paper becomes brittle after high-temperature purification in the traditional method is avoided.
In conclusion, the carbon content of the graphite paper is remarkably improved: the carbon content of the common graphite paper prepared by the traditional method is 98 wt% or more, and through the two optimization steps, the carbon content of the graphite paper can be increased to 99.8 wt% or more.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate the features and advantages of the invention and not to limit the scope of the claims.
The application provides a preparation method of high-purity graphite paper, which comprises the following steps in sequence:
1) putting graphite powder into a graphite crucible;
2) putting a graphite crucible containing graphite powder into a vacuum furnace or a gas high-temperature furnace, vacuumizing the vacuum furnace or the gas high-temperature furnace and raising the temperature in the furnace for purification, wherein the heat preservation temperature in the purification process is 1900-2500 ℃, the heat preservation time is 1-7 h, the vacuum degree in the furnace is 0.1-1000 Pa, and furnace cooling is carried out after the heat preservation process is finished;
3) taking out the graphite crucible after furnace cooling is finished, and then pouring graphite powder in the graphite crucible into a container;
4) acid treatment: pouring a mixed solution of an oxidant and concentrated sulfuric acid into the container filled with the graphite powder after the step 3), and uniformly stirring;
5) washing with water: cleaning the graphite powder subjected to acid treatment in the step 4) with pure water until the pH value of wastewater generated after water washing reaches 6-7;
6) drying the graphite powder prepared after the water washing in the step 5) until the water content in the graphite powder is reduced to 25-35 wt%;
7) putting the dried graphite powder obtained in the step 6) into an expansion furnace for expansion treatment to obtain expanded graphite;
8) rolling: and (3) rolling the expanded graphite prepared in the step (7), and obtaining finished graphite paper after the rolling treatment is finished.
In one embodiment of the present application, in step 1), the graphite powder is flake graphite powder, and the carbon content in the flake graphite powder is 99.5 wt% to 99.9 wt%.
In an embodiment of the application, in the step 2), after the vacuum pumping is completed, a halogen gas is introduced into the vacuum furnace or the gas high-temperature furnace, and the high-temperature purification treatment is performed in a halogen gas atmosphere, wherein the halogen gas is one, two or three of hydrogen chloride, freon and chlorine.
In an embodiment of the application, in the step 4), the concentrated sulfuric acid is 95% or 98% concentrated sulfuric acid by mass;
the oxidant is hydrogen peroxide and/or potassium dichromate.
In one embodiment of the present application, the expansion process in step 7) is an instantaneous expansion at 900 ℃ to 1100 ℃.
Devices and methods not described in detail in the present application are all the prior art and are not described in detail.
For further understanding of the present invention, the following examples are provided to illustrate the preparation of a high purity graphite paper according to the present invention, and the scope of the present invention is not limited by the following examples.
Example 1
A preparation method of high-purity graphite paper comprises the following steps of:
1) putting graphite powder into a graphite crucible;
in the step 1), the graphite powder is flake graphite powder, and the carbon content in the flake graphite powder is 99.5 wt%;
2) putting a graphite crucible containing graphite powder into a vacuum furnace, vacuumizing the vacuum furnace, raising the temperature in the vacuum furnace for purification, keeping the temperature at 2400 ℃ in the purification process for 6 hours, keeping the vacuum degree in the furnace at 10Pa, and cooling along with the furnace after the temperature keeping process is finished;
3) taking out the graphite crucible after furnace cooling is finished, and then pouring graphite powder in the graphite crucible into a container;
4) acid treatment: pouring a mixed solution of an oxidant and concentrated sulfuric acid into the container filled with the graphite powder after the step 3), and uniformly stirring;
in the step 4), the concentrated sulfuric acid is 98% by mass;
the oxidant is hydrogen peroxide, and the volume of the hydrogen peroxide is 10:90 of concentrated sulfuric acid;
5) washing with water: cleaning the graphite powder subjected to acid treatment in the step 4) with pure water until the pH value of wastewater generated after water washing reaches 6-7;
6) drying the graphite powder prepared after the water washing in the step 5) until the water content in the graphite powder is reduced to 25-35 wt%;
7) putting the dried graphite powder obtained in the step 6) into an expansion furnace for expansion treatment to obtain expanded graphite;
in the step 7), the expansion treatment is instantaneous expansion at 1000 ℃;
8) rolling: and (3) rolling the expanded graphite prepared in the step (7), and obtaining finished graphite paper after the rolling treatment is finished.
The carbon content of the graphite paper prepared in example 1 was found to be 99.9 wt%, and the graphite paper did not become brittle.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
Claims (5)
1. The preparation method of the high-purity graphite paper is characterized by comprising the following steps of:
1) putting graphite powder into a graphite crucible;
2) putting a graphite crucible containing graphite powder into a vacuum furnace or a gas high-temperature furnace, vacuumizing the vacuum furnace or the gas high-temperature furnace and raising the temperature in the furnace for purification, wherein the heat preservation temperature in the purification process is 1900-2500 ℃, the heat preservation time is 1-7 h, the vacuum degree in the furnace is 0.1-1000 Pa, and furnace cooling is carried out after the heat preservation process is finished;
3) taking out the graphite crucible after furnace cooling is finished, and then pouring graphite powder in the graphite crucible into a container;
4) acid treatment: pouring a mixed solution of an oxidant and concentrated sulfuric acid into the container filled with the graphite powder after the step 3), and uniformly stirring;
5) washing with water: cleaning the graphite powder subjected to acid treatment in the step 4) with pure water until the pH value of wastewater generated after water washing reaches 6-7;
6) drying the graphite powder prepared after the water washing in the step 5) until the water content in the graphite powder is reduced to 25-35 wt%;
7) putting the dried graphite powder obtained in the step 6) into an expansion furnace for expansion treatment to obtain expanded graphite;
8) rolling: and (3) rolling the expanded graphite prepared in the step (7), and obtaining finished graphite paper after the rolling treatment is finished.
2. The method for preparing high-purity graphite paper according to claim 1, wherein in the step 1), the graphite powder is flake graphite powder, and the carbon content in the flake graphite powder is 99.5-99.9 wt%.
3. The method for preparing high-purity graphite paper according to claim 1, wherein in the step 2), after the vacuum pumping is completed, halogen gas is introduced into a vacuum furnace or a gas high-temperature furnace, and the high-temperature purification treatment is performed in a halogen gas atmosphere, wherein the halogen gas is one, two or three of hydrogen chloride, freon and chlorine.
4. The method for preparing high-purity graphite paper according to claim 1, wherein in the step 4), the concentrated sulfuric acid is 95% or 98% concentrated sulfuric acid in mass fraction;
the oxidant is hydrogen peroxide and/or potassium dichromate.
5. A process for preparing a high purity graphite paper as claimed in claim 1, wherein in step 7), the expansion treatment is instantaneous expansion at 900 ℃ to 1100 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010857161.8A CN111924837A (en) | 2020-08-24 | 2020-08-24 | Preparation method of high-purity graphite paper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010857161.8A CN111924837A (en) | 2020-08-24 | 2020-08-24 | Preparation method of high-purity graphite paper |
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| Publication Number | Publication Date |
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| CN111924837A true CN111924837A (en) | 2020-11-13 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
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| CN202010857161.8A Pending CN111924837A (en) | 2020-08-24 | 2020-08-24 | Preparation method of high-purity graphite paper |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106064815A (en) * | 2016-06-01 | 2016-11-02 | 陕西六元碳晶股份有限公司 | The high-purity graphite powder that the method for graphite powder purification and the method are prepared |
| CN108190882A (en) * | 2018-02-26 | 2018-06-22 | 乌兰察布市大盛石墨新材料股份有限公司 | Conductive graphite paper and preparation method thereof |
| CN108373152A (en) * | 2018-02-26 | 2018-08-07 | 乌兰察布市大盛石墨新材料股份有限公司 | Conductive graphite paper and preparation method thereof |
| CN109437952A (en) * | 2018-11-30 | 2019-03-08 | 大同新成新材料股份有限公司 | A kind of method that C/C composite prepares graphite paper |
| US20190112195A1 (en) * | 2016-03-22 | 2019-04-18 | Institute Of Metal Research Chinese Academy Of Sciences | Method for Continuously Preparing Graphene Oxide Nanoplatelet |
| US20190210345A1 (en) * | 2018-01-08 | 2019-07-11 | Nanotek Instruments, Inc. | Graphene Paper Having High Through-Plane Conductivity and Production Process |
-
2020
- 2020-08-24 CN CN202010857161.8A patent/CN111924837A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20190112195A1 (en) * | 2016-03-22 | 2019-04-18 | Institute Of Metal Research Chinese Academy Of Sciences | Method for Continuously Preparing Graphene Oxide Nanoplatelet |
| CN106064815A (en) * | 2016-06-01 | 2016-11-02 | 陕西六元碳晶股份有限公司 | The high-purity graphite powder that the method for graphite powder purification and the method are prepared |
| US20190210345A1 (en) * | 2018-01-08 | 2019-07-11 | Nanotek Instruments, Inc. | Graphene Paper Having High Through-Plane Conductivity and Production Process |
| CN108190882A (en) * | 2018-02-26 | 2018-06-22 | 乌兰察布市大盛石墨新材料股份有限公司 | Conductive graphite paper and preparation method thereof |
| CN108373152A (en) * | 2018-02-26 | 2018-08-07 | 乌兰察布市大盛石墨新材料股份有限公司 | Conductive graphite paper and preparation method thereof |
| CN109437952A (en) * | 2018-11-30 | 2019-03-08 | 大同新成新材料股份有限公司 | A kind of method that C/C composite prepares graphite paper |
Non-Patent Citations (1)
| Title |
|---|
| 郝美英 等: "《矿产资源节约与综合利用鼓励、限制和淘汰技术汇编》", 31 January 2012, 地质出版社 * |
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Application publication date: 20201113 |
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