• Title/Summary/Keyword: Manganese dioxide

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Immobilized Small Sized Manganese Dioxide Sand in the Remediation of Arsenic Contaminated Water

  • Tiwari, Diwakar;Laldawngliana, C.;Lee, Seung-Mok
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.107-113
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    • 2014
  • Small sized manganese dioxide particles are immobilized onto the surface of sand by the wet impregnation process. The surface morphology of the solid, i.e., immobilized manganese dioxide natural sand (IMNS) is performed by taking scanning electron microscope images and characterized by the X-ray diffraction data. The specific surface area of the solid is obtained, which shows a significant increase in the specific surface area obtained by the immobilization of manganese dioxide. The $pH_{PZC}$ (point of zero charge) is found to be 6.28. Further, the IMNS is assessed in the removal of As(III) and As(V) pollutants from aqueous solutions under the batch and column operations. Batch reactor experiments are conducted for various physicochemical parametric studies, viz. the effect of sorptive pH (pH 2.0-10.0), concentration (1.0-25.0 mg/L), and background electrolyte concentrations (0.0001-0.1 mol/L $NaNO_3$). Further, column experiments are conducted to obtain the efficiency of IMNS under dynamic conditions. The breakthrough data obtained by the column experiments are employed in non-linear fitting to the Thomas equation, so as to estimate the loading capacity of the column for As(III) and As(V).

Manganese Dioxide-Based Chlorination of Alcohols Using Silicon Tetrachloride (이산화망간 존재하에서 사염화규소를 이용한 알코올의 염소화반응)

  • Ha, Dong Soo;Yoon, Myeong Jong
    • Journal of the Korean Chemical Society
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    • v.41 no.10
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    • pp.541-546
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    • 1997
  • Manganese dioxide may react with silicon tetrachloride to form manganese(Ⅳ) oxodichloride which reacts subsequently with another molecule of silicon tetrachloride leading to manganese tetrachloride eventually in chlorinated solvents. This in situ generated manganese(Ⅳ) oxodichloride or manganese tetrachloride were found to be very effective for the chlorination of a wide variety of alcohols to the corresponding chlorides. Primary, secondary and benzylic alcohols were converted into corresponding chlorides when treated with silicon tetrachloride in the presence of manganese dioxide at room temperature.

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Survey on rechargeable battery of MnO2-Zn using aqueous solution (수용성 전해질을 이용한 이산화망간 2차 전지에 대한 고찰)

  • Park, S.J.;Shin, H.S.;Kim, Y.C.;Oh, C.S.
    • Journal of Energy Engineering
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    • v.25 no.4
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    • pp.245-250
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    • 2016
  • Manganese dioxide is the material which has a good characteristic property for a secondary cell. We have surveyed on rechargeable battery of zink-manganese dioxide using aqueous solution and we also surveyed on redox reversibility of zink-manganese dioxide for checking up possibility for a secondary cell. We have found out to be active for charging and discharging of those.

Reduction Leaching of Manganese Dioxide Ore Using Black Locust as Reductant in Sulfuric Acid Solution

  • Xue, Jianrong;Zhong, Hong;Wang, Shuai;Li, Changxin;Li, Jinzhong;Wu, Fangfang
    • Korean Chemical Engineering Research
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    • v.53 no.4
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    • pp.509-516
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    • 2015
  • We investigated the reduction leaching process of manganese dioxide ore using black locust as reductant in sulfuric acid solution. The effect of parameters on the leaching efficiency of manganese was the primary focus. Experimental results indicate that manganese leaching efficiency of 97.57% was achieved under the optimal conditions: weight ratio of black locust to manganese dioxide ore (WT) of 4:10, ore particle size of $63{\mu}m$, $1.7mol{\cdot}L^{-1}\;H_2SO_4$, liquid to solid ratio (L/S) of 5:1, leaching time of 8 h, leaching temperature of 368 K and agitation rate of $400r{\cdot}min^{-1}$. The leaching rate of manganese, based on the shrinking core model, was found to be controlled by inner diffusion through the ash/inert layer composed of associated minerals. The activation energy of reductive leaching is $17.81kJ{\cdot}mol^{-1}$. To conclude the reaction mechanism, XRD analysis of leached ore residue indicates manganese compounds disappear; FTIR characterization of leached residue of black locust sawdust shows hemicellulose and cellulose disappear after the leaching process.

A Study on Cathode active material of Li/MnO$_2$ Battery for performance improvement (성능향상을 위한 리튬전지의 Cathode active material에 관한 연구)

  • 김학주;송수정
    • Proceedings of the KAIS Fall Conference
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    • 2001.11a
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    • pp.79-84
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    • 2001
  • 본 논문에서는 리튬전지의 Cathode active material로 CMD(chemical manganese dioxide)를 사용하여 현재 사용중인 EMD(electrolytic manganese dioxide)와 공정 수율 및 특성과 방전 성능을 비교함으로써 새로운 cathode active material.로의 적용 가능성을 확인하기 위함이다.

Reaction Kinetics and Dependence of Energy Efficiency in the Dilute Trichloroethylene Removal by Non-thermal Plasma Process combined with Manganese Dioxide

  • Han, Sang-Bo;Oda, Tetsuji;Park, Jae-Youn;Koh, Hee-Seok;Park, Sang-Hyun;Lee, Hyun-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.552-553
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    • 2005
  • In order to improve energy efficiency in the dilute trichloroethylene removal using the nonthermal plasma process, the barrier discharge treatment combined with manganese dioxide was experimentally studied. Reaction kinetics in this process was studied on the basis of final byproducts distribution. Decomposition efficiency was improved to about 99% at the specific energy 40J/L with passing through manganese dioxide. C=C $\pi$ bond cleavage in TCE gave DCAC (single bond, C-C) through oxidation reaction during the barrier discharge plasma treatment. Those DCAC were broken easily in the subsequent catalytic reaction due to the weak bonding energy about 3 ~ 4 eV compared with the double bonding energy in TCE molecules. Oxidation byproducts of DCAC and TCAA from TCE decomposition are generated from the barrier discharge plasma treatment and catalytic surface chemical reaction, respectively. Complete oxidation of TCE into $CO_X$ is required to about 400J/L.

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Electrochemical Properties of MnO$_2$electrode for supercapactor wish a Diffuser (Polyvinylalcohol) (분산제 PVA에 따른 수퍼커패시터용 이산화망간전극의 전기 화학적 특성)

  • 이상오;김한주;박수길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.753-756
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    • 2001
  • This research made a study of MnO$_2$electrode for supercapacitor with a diffuser (Polyvinyl alcohol). Manganese dioxide was used as active material. We tried to increase specific surface area by adding PVA. Manganese dioxide was synthesized by a sol-gel method using fumaric acid and oxalic acid in low temperature with high yield. Therefore, We prepared Manganese dioxide powder. This powder was used by active materials. The electrode was made by a mixture of active material, ketjen-black which is a large specific surface area, and PVdF-co-HFP as binder agent with using Nickel mesh as current collector. Here we reported on the synthesis and electrochemical performance of a enhanced material. All active materials have been submitted to X-ray diffraction and Scanning electron microscopy.

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Properties of Cement Mortar with Manganese Doped Titanium Dioxide Nano-Wires (망간 도핑 이산화티탄 나노와이어를 혼입한 시멘트 모르타르의 특성)

  • Lee, Jun-Cheol;Hou, Yao-Long
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.323-324
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    • 2023
  • The properties of cement mortar mixed with manganese-doped titanium dioxide nanowires (TiO2(Mn)-NWs) were investigated in this study. The TiO2(Mn)-NWs were synthesized using solvo-thermal synthesis and electro-spinning techniques. The TiO2(Mn)-NWs at weights of 1%, 2%, and 3% of the cement were respectively mixed into the cement mortar. The results showed that as the amount of TiO2(Mn)-NWs increased, the flow value of the cement mortar was decreased and the setting time of cement mortar was accelerated. Moreover, as the amount of TiO2(Mn)-NWs increased, the compressive strength of cement mortar was increased and the efficiency of acetaldehyde removal was improved.

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The Removal of Silver in the Fixer Wastewater of X-ray Film Using Manganese Dioxide (이산화망간을 이용한 x-ray 필름 정착폐액중의 은 제거)

  • 박정호;오성훈;전용보;임찬섭;박승조
    • Resources Recycling
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    • v.6 no.4
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    • pp.11-16
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    • 1997
  • The wastewater resulted from the process of developing and fuing for x-ray film manufachlring contains a lot of silvercomponent. The average concentation of silver-component is about 1,500 mgA. The wastewater contained silver-component is toxic when it is discharged to the natural ecosystem. So that we must to do pretreatment of wastewater prior to discharge. There are electrolysis. chemical precipitation, and metallic replacement as conventional lreabent proccss of fixer wastewater of x-ray film. Adsorption of silver-component in x-ray fkcr wastewater was carricd out this study. 'Ille manganese dioxide (MDO) reagent and the recovered manganese dioxide (RMDO) from the waste dry-cell were used for adsarbents. Adsorption of silvercomponent was wrried out at the batch and continuous type experimental equipment. The adsorption experiment results were obtained bom silver-component have some diifcrences according to adsorhents. The adsorption results of manganese dioxide reagent (MDO) were better ihan those of waste dry-ccU (RMDO), but the manganese dloxide recovered fmm waste dry-cell (RMDO) will be able la recognized as good adsorbent too.

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