• Title/Summary/Keyword: LiCl-KCl

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Effects of Li2O Addition and Heat-Treatment on Formability of FeS2 Powder for Cathode of Thermal Battery (열전지 양극용 FeS2 분말의 성형성에 미치는 Li2O 첨가 및 열처리의 효과)

  • Ryu, Sung-Soo;Lee, Won-Jin;Kim, Seongwon;Cheong, Hae-Won;Cho, Sung-Baek;Kang, Seung-Ho;Lee, Sung-Min
    • Journal of Powder Materials
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    • v.21 no.3
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    • pp.185-190
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    • 2014
  • $FeS_2$ has been widely used for cathode materials in thermal battery because of its high stability and current capability at high operation temperature. Salts such as a LiCl-KCl were added as a binder for improving electrical performance and formability of $FeS_2$ cathode powder. In this study, the effects of the addition of $Li_2O$ in LiCl-KCl binder on the formability of $FeS_2$ powder compact were investigated. With the increasing amount of $Li_2O$ addition to LiCl-KCl binder salts, the strength of the pressed compacts increased considerably when the powder mixture were pre-heat-treated above $350^{\circ}C$. The heat-treatment resulted in promoting the coating coverage of $FeS_2$ particles by the salts as $Li_2O$ was added. The observed coating as $Li_2O$ addition might be attributed to the enhanced wettability of the salt rather than its reduced melting temperature. The high strength of compacts by the $Li_2O$ addition and pre-heat-treatment could improve the formability of $FeS_2$ raw materials.

Calculations of Solubility Preduct Constants for Metal Oxides in the KCI-LiCl Eutectic Composition by Exact Thermodynamic Cycle (KCl-LiCl 공정 용융염욕에서 열역학적 싸이클법에 의한 금속산화물의 용해도적 계산)

  • 백영현
    • Journal of the Korean institute of surface engineering
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    • v.23 no.4
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    • pp.225-229
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    • 1990
  • Solubility Products of metal oxides, such as Al2O3 and UO2 in KCl-LiCl eutectic composition was calculated by using an exact an exact thermodynamic. The values for Al2O3 ThO2 and UO2 were found to be 2.51$\times$10-27, 4.97$\times$10-15and 2.17$\times$10-12in mole per liter basis at 743 K, respectively. The correlation of theoretical values with those of experiment were in good agreement. It is worth to note that the exact cycle method was proved to be satisfactory in making predictions of solubillities and also solubility products of sparingly soluble metal oxides in an ionic salt system.

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Electrolytic Boronzing on TiAl-based Intermetallic Compounds in Fused Salt of Borax, Potassium Chloride and Lithium Chloride Mixture (Na$_2$B$_4$O$_7$-KCl-LiCl 혼합용융욕에서 TiAl계 금속간 화합물의 전해붕화처리)

  • 이두환;김익범;이주호;김수식
    • Journal of the Korean institute of surface engineering
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    • v.31 no.6
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    • pp.359-370
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    • 1998
  • TiAl-based intermetallic compounds were electro-bornizel in the mixture of $Na_2B_4O_7$, KCL and LiCl in the termetature rage between 850 and $1000^{\circ}C$for various times (1-5 hours)under the fixed current density of 0.5 A/$cm^2$. The optimized composition of electrolyte in this work was decided to be 76.9 wt% $Na_2B_4O_7$-19.2 wt.%(0.7KCl-0.3LiCl) -3.9 wt.% al. The samples with boronized layer were investigated by SEM, XRD and EDS. The surface micro-hardness of boronized TiAl was also evaluated using Micro Vickers Hardness Tester. The sample, boronized at $900^{\circ}C$ for 4 hours in the above composition of electrolyte under the current density of 0.5 A/$\textrm{cm}^2$, has about 36$\mu\textrm{m}$ think layer on the surface, and its surface micro-hardness was measured to be 1263 Hv. From the results of SEM, XRD and EDS, the layer consisted of $TiB_2$ sublayer and Al-oxide sub layer. Al-depleted layer below the Al-oxide sudlayer was also detected. The activation energy for formation of boronized layer in this study was calculated as 178 Kcal/moleK.

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EPR Investigation on a Quantitative Analysis of Eu(II) and Eu(III) in LiCl/KCl Eutectic Molten Salt

  • Park, Yong-Joon;Kim, Tack-Jin;Cho, Young-Hwan;Jung, Yong-Ju;Im, Hee-Jung;Song, Kyu-Seok;Jee, Kwang-Yong
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.127-129
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    • 2008
  • EPR spectroscopic technique was applied for a quantitative analysis of Eu(II) for a speciation of europium in a LiCl-KCl eutectic melt. By adopting the first absorption line of each isotopes (151Eu and 153Eu), a calibration plot was obtained. The calibration of the EPR intensity shows a good linearity according to the amount of Eu(II). The EPR intensity was identified to increase proportionally with a decrease of the attenuation parameter for EPR microwave power. The fluorescence technique was used qualitatively to find whether either of Eu(II) or Eu(III) ions exists in a molten salt sample. The ICP-AES technique was also adopted to determine the total concentration of europium in the sample, since EPR is only sensitive for detecting the Eu(II) ion. The extent of the reduction of Eu(III) in the LiCl-KCl eutectic melt at 723 K was determined by using this technique.

Fundamental Study on a Distillation Separation of a LiCl-KCl Eutectic Salt from Rare Earth Precipitates (희토류 침전물로부터 LiCl-KCl 공융염의 증류 분리에 관한 기초연구)

  • Yang, Hee-Chul;Eun, Hee-Chul;Kim, In-Tae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.1
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    • pp.65-70
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    • 2010
  • The distillation rate on LiCl-KCl eutectic salt under different vacuums from 0.5-50 mmHg was first investigated by using both a non-isothermal and a isothermal thermogravimetric (TG) analysis. Based on the non-isothermal TG data, distillation rate equations as a function of the temperature could be derived. Calculated flux by these model flux equations was in agreement with the distillation rate obtained from isothermal TG analysis. A distillation rate of $10^{-4}-10^{-5}$ mole $cm^{-2}sec^{-1}$ is obtainable at temperatures less than 1300K and vacuums of 0.5-50 mmHg. About a 99% salt distillation efficiency was obtained after an hour at a temperature above 1150 K under 50 mmHg in a small scale distillation test system. An increase in the vaporizing surface area is relatively effective for removing residual salt in the remaining particles, when compared to that for the vaporizing time. Over 99.95% of total distillation efficiency was obtained for a 1-h distillation operation by increasing the inner surface area from $4.52cm^2$ to $12.56cm^2$.

Solvation Number and Selective Solvation of Ions in Water-Methanol Systems (물-메탄올 混合溶媒中에서 이온들의 溶媒和數와 選擇的 溶媒和)

  • Jong-Jae Chung;Hag-Sung Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.3
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    • pp.309-316
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    • 1993
  • The limiting equivalent ionic conductances of Li$^+$, Na$^+$, K$^+$, Cl$^-$, and Br$^-$ ions were obtained with TATB[Tetraphenyl Arsonium Tetraphenyl Borate] method from limiting equivalent conductances of LiCl, NaCl, KCl and KBr measured in water-methanol systems by conductometric method. With those values and viscosity of water-methanol systems, the Stokes radii of corresponding ions have been extracted. The latter values corrected by calibration method of Nightingale and supplemented by the crystallographic radii were utilized to calculate the volume of solvation-shell that surrounds ions. The reasonable solvation numbers (h$_{H_2O}$ + h$_0$) were estimated by comparing the values obtained by the various suggested methods. The selective properties of ion solvation were also discussed.

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