{"title":"在初始熔体中不含卤化钛的情况下,用溶解在BaCl2-CaCl2-NaCl熔体中的钠对其离子进行体积电解还原法制备微分散钛粉","authors":"V. Lebedev, V. Polyakov","doi":"10.17073/1997-308x-2022-4-14","DOIUrl":null,"url":null,"abstract":"The paper is devoted to a detailed study of cathodic processes, their influence on the anode process, and electrolysis performance. The polarization of a steel cathode in a CaCl2–BaCl2–NaCl melt at t = 610 °C was measured. The polarization curve clearly shows the potentials and current densities of the formation of a saturated sodium solution in the electrolyte (Esat = –2.97 V, ic = 0.04 A/cm2, lgic = –1,4), and the occurrence of sodium metal on the cathode (ENa = –3.22 V, iNa = 0.12 A/cm2, lgiNa = –0.92).The value of Esat was used to calculate the concentration of sodium in the electrolyte at t = 610 °С (1.3·10–4 mol. fr.). The values of Esat, ENa, and their difference (E = 0,25 В) were confirmed by long-term electrolysis. These fundamental characteristics are the basis for process control and management. During long-ter 3 regions close to rectilinear ones were revealed: the discharge of sodium ions from supersaturated solutions at E more negative than Esat (from ENa to Esat), from mixtures of supersaturated and saturated solutions (at a constant E equal to Esat), from diluted solutions (with E more positive than Esat). The activity coefficients of sodium in supersaturated solutions are close to 1, which ensures their increased reducing ability. Maximum degrees of supersaturation (>100) are created at formation and decomposition on the cathode of metallic sodium nuclei, which are sufficient to intensify and prolong electrolysis, to lower the lower temperature limit of its realization from 600 to 350 °С. The formation of metallic titanium in the near-anode layer is explained by the disproportionation of Ti2+ ions entering the near-anode electrolyte from the anode surface and from the near-cathode melt.","PeriodicalId":14693,"journal":{"name":"Izvestiya vuzov. Poroshkovaya metallurgiya i funktsional’nye pokrytiya","volume":"294 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Electrode processes in the production of microdispersed titanium powder by volumetric electrolytic reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt in the absence of titanium halides in the initial melt\",\"authors\":\"V. Lebedev, V. 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During long-ter 3 regions close to rectilinear ones were revealed: the discharge of sodium ions from supersaturated solutions at E more negative than Esat (from ENa to Esat), from mixtures of supersaturated and saturated solutions (at a constant E equal to Esat), from diluted solutions (with E more positive than Esat). The activity coefficients of sodium in supersaturated solutions are close to 1, which ensures their increased reducing ability. Maximum degrees of supersaturation (>100) are created at formation and decomposition on the cathode of metallic sodium nuclei, which are sufficient to intensify and prolong electrolysis, to lower the lower temperature limit of its realization from 600 to 350 °С. The formation of metallic titanium in the near-anode layer is explained by the disproportionation of Ti2+ ions entering the near-anode electrolyte from the anode surface and from the near-cathode melt.\",\"PeriodicalId\":14693,\"journal\":{\"name\":\"Izvestiya vuzov. 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引用次数: 0
摘要
本文详细研究了阴极过程及其对阳极过程和电解性能的影响。在t = 610℃时,测量了钢阴极在CaCl2-BaCl2-NaCl熔体中的极化。极化曲线清晰地显示了电解质中形成饱和钠溶液的电位和电流密度(Esat = -2.97 V, ic = 0.04 a /cm2, llogic = - 1,4),以及阴极上金属钠的发生(ENa = -3.22 V, iNa = 0.12 a /cm2, lgiNa = -0.92)。用Esat值计算t = 610°С(1.3·10-4 mol. fr.)时电解质中钠的浓度。Esat、ENa值及其差值(E = 0,25 В)经长期电解确认。这些基本特征是过程控制和管理的基础。在较长的时间内,发现了3个接近直线的区域:在E比Esat更负的过饱和溶液中(从ENa到Esat),在过饱和溶液和饱和溶液的混合物中(在恒定的E等于Esat时),在稀释溶液中(E比Esat更正),钠离子的放电。钠在过饱和溶液中的活度系数接近于1,保证了其还原能力的增强。金属钠核在阴极形成和分解时产生最大过饱和度(>100),这足以加强和延长电解,使其实现的下限从600°降至350°С。金属钛在近阳极层的形成可以解释为从阳极表面和近阴极熔体进入近阳极电解质的Ti2+离子的歧化。
Electrode processes in the production of microdispersed titanium powder by volumetric electrolytic reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt in the absence of titanium halides in the initial melt
The paper is devoted to a detailed study of cathodic processes, their influence on the anode process, and electrolysis performance. The polarization of a steel cathode in a CaCl2–BaCl2–NaCl melt at t = 610 °C was measured. The polarization curve clearly shows the potentials and current densities of the formation of a saturated sodium solution in the electrolyte (Esat = –2.97 V, ic = 0.04 A/cm2, lgic = –1,4), and the occurrence of sodium metal on the cathode (ENa = –3.22 V, iNa = 0.12 A/cm2, lgiNa = –0.92).The value of Esat was used to calculate the concentration of sodium in the electrolyte at t = 610 °С (1.3·10–4 mol. fr.). The values of Esat, ENa, and their difference (E = 0,25 В) were confirmed by long-term electrolysis. These fundamental characteristics are the basis for process control and management. During long-ter 3 regions close to rectilinear ones were revealed: the discharge of sodium ions from supersaturated solutions at E more negative than Esat (from ENa to Esat), from mixtures of supersaturated and saturated solutions (at a constant E equal to Esat), from diluted solutions (with E more positive than Esat). The activity coefficients of sodium in supersaturated solutions are close to 1, which ensures their increased reducing ability. Maximum degrees of supersaturation (>100) are created at formation and decomposition on the cathode of metallic sodium nuclei, which are sufficient to intensify and prolong electrolysis, to lower the lower temperature limit of its realization from 600 to 350 °С. The formation of metallic titanium in the near-anode layer is explained by the disproportionation of Ti2+ ions entering the near-anode electrolyte from the anode surface and from the near-cathode melt.