• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The use of an isotropic carbon block having an anisotropy of not more than 1.2 in terms of an anisotropic ratio of specific resistance as an anode in the production of fluorine by the electrolysis of an electrolyte comprising a mixed molten salt system of potassium fluoride and hydrogen fluoride has been found to be extremely useful for attaining increase in critical current density so that occurrence of the unfavorable anode effect can be effectively prevented. With such an isotropic carbon block anode, even if the anode effect occurs, the electrolysis can be stably continued again by lowering the potential of the electrode. Further, the incorporation of a fluoride into the isotropic carbon block anode and/or the addition of a fluoride into the electrolyte is effective for further increasing critical current density.
    公开号:SU1303037A3
    申请号:SU802953756
    申请日:1980-07-31
    公开日:1987-04-07
    发明作者:Ватанабе Нобуацу；Арамаки Минору；Кита Есуси
    申请人:Нобуацу Ватанабе (Фирма)；Сентрал Гласс Компани Лимитед (Фирма)；Тойо Тансо Ко.,Лтд (Фирма)；
    IPC主号:
    专利说明:

    The invention relates to a method for producing fluorine using an electrolytic cell with molten salt and using a carbon electrode as an anode.
    The aim of the invention is to increase the reliability of the process by eliminating the anode effect with increasing current density.
    During the electrolysis of molten salt electrolyte, including fluoride, with a carbon electrode as an anode, the so-called anode effect is usually observed, which is a sharp spontaneous increase in voltage and a decrease in current due to anodic polarization,
    In the case of the production of fluorine by electrolysis of an electrolyte containing a molten salt system, the phenomenon of the anode effect tends to occur even under conditions of relatively low current densities. Therefore, in the conventional method of producing fluorine by electrolysis in order to prevent the occurrence of the anode effect, electrolysis is carried out at even lower current densities.
    As a criterion for the occurrence of the anode effect, it is possible to indicate the critical value of the current density (denoted by QPT) at which the anode effect occurs.
    Isotropic carbon blocks with anisotropy 1.10 (in values corresponding to the anisotropic ratio of resistivity) are prepared as follows. Petroleum coke is ground to an average particle size of 15 µm, and then deglie pitch is added in an amount of 1/2 of the amount of petroleum coke. The resulting mixture is transferred at 200 ° C. using a Z stirrer until the concentration of volatile matter is 12%. After cooling, the mixture is subjected to secondary grinding to obtain particles. The particles are passed through a sieve of 800 mesh. and used as raw material for pressing. The raw material thus obtained is subjected to extrusion by cold isotropic pressing under a pressure of 1000 atm / cm followed by heat treatment.
    The heat treatment is carried out in such a way that the pressed particles are heated to
    a temperature rise of 3 ° C / h and kept at this temperature for 2A h. After cooling, a carbon product is obtained, which is then cut to give the desired isotropic coal blocks
    The resulting coal blocks had dimensions (19x10x10 mm) and were used as an anode.
    The anisotropy value of 1.40 is essentially the same as that of the known coal block, which is usually used as an anode in the production of fluorine by electrolysis of electrolyte, which is a mixed salt molten system of KF and HF,
    The electrolyte used is a molten mixture of salts of the KF-2 HF system. The KPT value is measured at 100 ° C using the potential sweep method. The results are presented in Table 1.
    As follows from Table 1, a coal block with anisotropy of 1.0-1.2 allows an increase in QPT.
    In addition, electrolytes containing KF - HF are used, respectively, with LiF, CaF, AlF, NaF, ZnF and NiF introduced. The KPT values are measured in this way. The results of the experiments are given in table 2 and 3.
    As follows from Tables 2 and 3, in the case of an isotropic coal block, the effect of adding fluoride to the melt is clearly observed at a concentration of 0.1-6% by weight of the melt.
    When the coal block used as the carbon anode has an anisotropy of 1.0-1.2 (in terms of the anisotropic ratio of resistivity), a noticeable increase in QPT is observed, at which anode effect can be effectively prevented, which leads to large advantages in terms of the production process. For example, when a coal block having anisotropy of 1.10 (in terms of anisotropic resistivity ratio) is used as a carbon anode in the production of fluorine by electrolysis of electrolyte from a mixture of molten salts of the KF - HF system (at a molar ratio of KF / HF 1 / 2 below, denoted by the system KF - 2 HF), the definitions by the sweep method and the potential show that the QPT value has increased to 36 A / dm.
    In another aspect of the invention, the amount of CPT in the electrolytic production of fluorine from the electrolyte, which is a molten mixture of salts of the KF-HF system, cannot be further increased by using an isotropic carbon block with an anisotropy of no more than 1.2 and containing fluoride inclusions. In general, in the production of isotropic coal blocks, the forming operation is performed before heat treatment at a temperature of from about 800 to about. Turning on fluoride can be
    This is achieved by adding carbon fluoride to the raw salt electrolytic bath with the raw salt followed by molding the resulting mixture, followed by heat treatment. In this connection, however, it is noted that the features and the moment 20 of the introduction of fluoride are not limited to those mentioned. As examples of fluoride passing for this purpose, lithium, sodium, calcium, zinc, aluminum or nickel fluorides may be mentioned. Cog-25 and the amount of fluoride included in the isotropic block are too small, and the effect of fluoride does not appear. On the other hand, when the amount of fluoride is excessively large, not only the proportionality effect for a high fluoride content is not achieved, but also the effective area of the coal block, functioning in
    us In particular, in the case of a non-consumable type electrode (which refers to an electrode used in a mixed salt molten electrolyte of the KF-HF system for electrolytic fluorine production), maintaining the strength (durability) of the electrode in the molten electrolytic bath is of paramount importance.
    Compliance with a further aspect of the invention increases the amount of CPT when electrolytically obtaining fluoride by electrolysis of a mixed salt molten electrolyte of the KF - HF system in an electrolytic cell with an isotropic carbon block used as an anode, having an anisotropy of 1.0-1.2 (according to an anotropic anodic characteristic of anode , is reduced by the result of 35 specific resistivity), or
    The inclusion of an excess amount of fluoride, which leads to an adverse effect on the functioning of the coal block as an anode. For this reason, the amount of fluoride to be submerged 40 salt mixed electrically in an isotropic unit should preferably be from 0, 1 to 5% by weight (relative to the weight of the isotropic carbon anode). For example,
    lit KF - HF system. As examples of fluorides suitable for this purpose, lithium, sodium, calcium, zinc fluorides can be mentioned here.
    when the isotropic coal block, has- 45 aluminum or nickel. When an anisotropy of 1.10 and containing 1% (mass of isotropic carbon anode block) of included LiF is used as an anode for electrolytic production of fluorine from electrolyte 50 from molten salt mixture, forming a KF - 2 HF system, then sweep measurement showed an increase in the CPT value to 46 A / dm2. 55
    fluoride included in the electrolyte exceeds the value corresponding to the fluoride solubility in the electrolyte, i.e. CBbmie is 6% by weight of the melt, there is a favorable tendency for fluoride to accumulate in the form or at the bottom of an electrolytic cell. A suitable amount of fluoride to be included in the electrolytic bath is in the range of 0.1-6% by weight of the melt.
    The inclusion of fluoride in an isotropic block is essential from a practical point of view.
    The examples show that an anisotropic carbon block having fluoride incorporation has extremely low resistance or strength when used as an anode in a molten salt electrolyte of the KF - HF system for electrolytic production of fluorine, and therefore cannot be practically used. In general, an essential requirement for an electrode to be used in a molten salt electrolytic bath is to maintain its strength. Under conditions of exposure to a melt. In particular, in the case of a non-consumable type electrode (which refers to an electrode used in a mixed salt molten electrolyte of the KF-HF system for electrolytic fluorine production), maintaining the strength (durability) of the electrode in a molten electrolytic bath
    Compliance with a further aspect of the invention increases the amount of CPT when electrolytically obtaining fluoride by electrolysis of a mixed salt molten electrolyte of the KF - HF system in an electrolytic cell with an isotropic carbon block used as an anode, having anisotropy of 1.0-1.2 (according to anisotropic characteristic of isotropic coal block with anisotropy of 1.0-1.2, but with fluoride inclusions, obtained by the introduction of fluorides included in the specified sputter of the KF-HF system. As examples of fluorides, od boiling for this purpose, there may be mentioned lithium fluoride, sodium, calcium, zinc.
     aluminum or nickel. When the quantity
     aluminum or nickel. When the quantity
    fluoride included in the electrolyte exceeds the value corresponding to the fluoride solubility in the electrolyte, i.e. CBbmie is 6% by weight of the melt, there is a favorable tendency for fluoride to accumulate in the form or at the bottom of an electrolytic cell. A suitable amount of fluoride to be included in the electrolytic bath is in the range of 0.1-6% by weight of the melt.
    Potassium fluoride and hydrogen fluoride, the main components of the KF - HF mixed molten salt electrolyte, can be used with different molar ratios in the range of at least 1. The preferred molar ratio of KF - HF is between 1.8 and 2, 2
    As for the cathode material, materials commonly used in the electrolytic production of fluorine can be used. Representative examples are iron, steel, nickel and monel metal.
    When the production of fluorine by the electrolysis of a mixed salt electrolyte of the KF - HF system is carried out using the anisotropic carbon block usually used as an anode, electrolysis cannot continue if even an anodic effect occurs even once. Conversely, when an isotropic carbon block having an anisotropy of 1.0-1.2 (characteristic of the anisotropic ratio of resistivity) is used as an anode in the electrolytic production of fluorine from the KF-HF mixed molten salt electrolyte, even if an anode effect occurs, then electrolysis, however unexpected, may continue again with a decrease in the cell voltage
    权利要求:
    Claims (3)
    [1]
    1. A method of producing fluorine by ruthem electrolysis of potassium fluoride melt and hydrogen fluoride at the anode, made in the form of a coal block, characterized in that, in order to increase the process reliability by eliminating the anode effect with increasing current density, a coal block with anisotropy in specific electrical resistance equal to 1.0-1.2,
    [2]
    2. Method POP1, characterized in that the coal block further comprises lithium fluoride, or sodium, or calcium, or zinc, or aluminum, or nickel in an amount of 0.1-5% by weight of the coal block.
    [3]
    3. A method according to claim 1 or 2, characterized in that the melt further comprises lithium fluoride, or sodium, or calcium, or zinc, or aluminum, or nickel in an amount of 0.1-6% by weight of the melt.
    Table 1
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    类似技术:
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    同族专利:
    公开号 | 公开日
    JPS5623285A|1981-03-05|
    FR2465796A1|1981-03-27|
    AU532307B2|1983-09-22|
    AU5943280A|1981-02-05|
    NL185294B|1989-10-02|
    NL185294C|1990-03-01|
    GB2054650A|1981-02-18|
    IT1148711B|1986-12-03|
    GB2054650B|1983-03-16|
    NL8003817A|1981-02-04|
    CA1153981A|1983-09-20|
    DE3027371A1|1981-02-12|
    US4312718A|1982-01-26|
    IT8023551D0|1980-07-18|
    JPS6112994B2|1986-04-11|
    DE3027371C2|1983-01-05|
    FR2465796B1|1984-03-16|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB655098A|1948-09-27|1951-07-11|William Norman Howell|Improvements in or relating to electrolysis of fluorine salts|
    FR1321083A|1962-04-05|1963-03-15|Ici Ltd|Process for the electrolytic production of fluorine, and corresponding apparatus|
    US3442787A|1966-05-17|1969-05-06|Exxon Research Engineering Co|High temperature fluid coke electrodes|
    US4226900A|1978-03-03|1980-10-07|Union Oil Company Of California|Manufacture of high density, high strength isotropic graphite|US4511440A|1983-12-22|1985-04-16|Allied Corporation|Process for the electrolytic production of fluorine and novel cell therefor|
    JPH0239842B2|1984-02-28|1990-09-07|Tlv Co Ltd|
    US4602985A|1985-05-06|1986-07-29|Eldorado Resources Limited|Carbon cell electrodes|
    JPS62152406U|1986-03-20|1987-09-28|
    GB2193225B|1986-08-01|1990-09-19|British Nuclear Fuels Plc|Carbon electrodes|
    JP2729254B2|1988-08-05|1998-03-18|信淳 渡辺|Low polarizable carbon electrode|
    JPH03245502A|1989-12-12|1991-11-01|Masao Imamura|Enclosed variable resistor|
    JPH03232988A|1990-02-06|1991-10-16|Toyo Tanso Kk|Carbon electrode, method and device for electrolyzing hf-containing molten salt using the same|
    CA2071235C|1991-07-26|2004-10-19|Gerald L. Bauer|Anodic electrode for electrochemical fluorine cell|
    US5651874A|1993-05-28|1997-07-29|Moltech Invent S.A.|Method for production of aluminum utilizing protected carbon-containing components|
    US6001236A|1992-04-01|1999-12-14|Moltech Invent S.A.|Application of refractory borides to protect carbon-containing components of aluminium production cells|
    US5310476A|1992-04-01|1994-05-10|Moltech Invent S.A.|Application of refractory protective coatings, particularly on the surface of electrolytic cell components|
    EP0688368B1|1993-03-09|1997-07-30|MOLTECH Invent S.A.|Treated carbon cathodes for aluminium production|
    WO1995006763A1|1993-09-03|1995-03-09|Minnesota Mining And Manufacturing Company|Fluorine cell|
    EP0782636B1|1994-09-08|1999-05-06|MOLTECH Invent S.A.|Aluminium electrowinning cell with improved carbon cathode blocks|
    US5753163A|1995-08-28|1998-05-19|Moltech. Invent S.A.|Production of bodies of refractory borides|
    US20030010354A1|2000-03-27|2003-01-16|Applied Materials, Inc.|Fluorine process for cleaning semiconductor process chamber|
    US6843258B2|2000-12-19|2005-01-18|Applied Materials, Inc.|On-site cleaning gas generation for process chamber cleaning|
    US20090001524A1|2001-11-26|2009-01-01|Siegele Stephen H|Generation and distribution of a fluorine gas|
    US20030121796A1|2001-11-26|2003-07-03|Siegele Stephen H|Generation and distribution of molecular fluorine within a fabrication facility|
    US20040037768A1|2001-11-26|2004-02-26|Robert Jackson|Method and system for on-site generation and distribution of a process gas|
    US20040151656A1|2001-11-26|2004-08-05|Siegele Stephen H.|Modular molecular halogen gas generation system|
    JP4339204B2|2004-08-05|2009-10-07|東洋炭素株式会社|Carbon electrode for generating nitrogen trifluoride gas|
    CA2779071A1|2009-11-09|2011-05-12|Rutgers, The State University Of New Jersey|Metal fluoride compositions for self formed batteries|
    US9692039B2|2012-07-24|2017-06-27|Quantumscape Corporation|Nanostructured materials for electrochemical conversion reactions|
    US20140110267A1|2012-10-19|2014-04-24|Air Products And Chemicals, Inc.|Anodes for the Electrolytic Production of Nitrogen Trifluoride and Fluorine|
    WO2016025866A1|2014-08-15|2016-02-18|Quantumscape Corporation|Doped conversion materials for secondary battery cathodes|
    CN111410213A|2020-04-02|2020-07-14|浙江博瑞中硝科技有限公司|Method for preparing potassium bifluoride by recycling waste electrolyte in fluorine gas production process|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    JP54098068A|JPS6112994B2|1979-08-02|1979-08-02|
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