몰리브덴酸이온의 還元 및 그 應用에 關한 硏究[第一報] : 酸性媒質 중에서 폴리몰리브덴酸이온의 還元

權利默 이화여자대학교 한국문화연구원 1966 韓國文化硏究院 論叢 Vol.8 No.-

The author has studied on the ionic species of polymolybdate which most easily reducible to molybdenum blue in sulfuric acid-ammonium paramolybdate-water solution, using spectrophotometer. (1) The most appropriate composition and pH of the solutions for the reduction is: concentration of H_2SO_4 in water: 2*10^-2~7*10^-2 mole/1, [H_2SO_4]/[(NH_4)_6 Mo_7O_24ㆍ4H_2O] mole ratio : 3~4 and 6~7, at concentration of 10^-2~3*10^-2 mole/1 and 10^-3~3*10^-3 mole/1 of the ammonium paramolybdate, respectively. The pH range of these solutions are about 1.6~2.4. (2) The octamolybdate ion and its still more condensed ionic form are the most easily reducible ions.

A Study on the Preparation of Electrolytic Manganese Dioxide

권이묵,김재원,지응업,신종주,Lee Mook Lee,Jae Won Kim,Ung Up Chi,Jong Ju Shin Korean Chemical Society 1973 대한화학회지 Vol.17 No.4

국산 rhodochrosite 로부터 제조한 황산산성 $MnSO_4$ 수용액을 전해산화하여 건전지용 ${\gamma}-MnO_2$를 제조하는데에 관한 공업적 데이터를 얻기 위하여 하루에 4kg의 $MnO_2$를 제조할 수 있는 micro pilot plant를 설치하여 실험하였다. 광석의 침출 및 전해산화 조건을 규명하고 제품의 물성을 화학분석, DTA, X-선회절, 전자현미경사진 및 전지방전 실험 등으로 검토하였다. 적합한 전해조건은 다음과 같다. 전해액의 온도 : $90^{\circ}C$ 이상, 전류밀도 : 0.7${\sim}A/dm^2$, 양극재료 : 흑연 또는 납, 전해액의 농도 :$MnSO_4 50{\sim}150g/l $및 $H_2SO_4/MnSO_4 = 0.15{\sim}0.25$. 최적전해조건하에서 전류효율은 99%이었고 생성된 $MnO_2$는 거의 순수한${\gamma}-MnO_2$이었으며, 방전특성은 우수하였다. With the intention of obtaining technical data for the industrial production of ${\gamma}-MnO_2$ for dry cell depolarizer by electrolytic oxidation of acidic manganese sulfate solution made from domestic rhodochrosite, optimum conditions of ore leaching, purification of leached solution and electrolytic oxidation of divalent manganes to tetravalent were investigated using simulated micro pilot plant having a production capacity of 4 kg of $MnSO_4$ per day. The nature and quality of the products were investigated by means of chemical analysis, DTA, X-ray diffraction and electron microscopy. The cell activity of $MnO_2$were examined by cell discharging character measurements. The optimum electrolysis conditions were as follow: Temperature of the electrolyte, above $90^{\circ}C$; current density, 0.7${\sim}A/dm^2$; anode materials, graphite or lead ; concentration of electrolyte, $MnSO_4 50{\sim}150g/l $ g/l and $H_2SO_4/MnSO_4 = 0.15{\sim}0.25$. Under the best condition the current efficiency was 99% and the products were almost pure ${\gamma}-MnO_2$. The cell discharging character were good and almost the same as that of regular grade commercial electrolytic manganese dioxide.

몰리브덴酸이온의 還元 및 그 應用에 關한 硏究[第二報] : 황산, 몰리브덴酸암모늄 및 그 混合 水溶液의 電氣傳導度와 이온會合

權利默 이화여자대학교 한국문화연구원 1966 韓國文化硏究院 論叢 Vol.8 No.-

Evaluation of degree of ion association and devising empirical formulae of equivalent conductance for dilute solution of sulfuric acid and ammonium paramolybdate (APM) at 25℃ are carried out from measured electrical conductivity. The degree of ion association are about 23% at 3*10^-2 eq/l of H_2SO_4, and about 80% at 10^-2 eq/l of APM. Very high degree of association or condensation of ions are evidenced in H_2SO_4-APM water solution at [H_2SO_4]/[APM] mole ratio of 0.5, 1.0, 3.0 and 6.0. Condensation of molybdate to octamolybdate ion in these solutions appear to occur at mole ratio of 3 and 6, an the final condensation reaction is: 수식 The devised empirical formula of equivalent conductance for very dilute H_2SO_4 solution at 25℃ is 수식 and agreement of the values of calculated with the measured are excellent, and fairly good with the values of International Critical Table (I.C.T.), for solutions weaker than 5*10^-3 eq/l of H_2SO_4. It seems that the I.C.T. values at 2*10^-4, 10^-3 and 2*10^-3 eq/l are not correct. The equivalent conductance of APM at infinite dilution is deduced as Λ°=713.6Ω^-1ㆍ㎠ㆍeq^-1 at 25℃, assuming that the hydrolysis reaction of APM at infinite dilution as follow; 수식 The devised empirical formula of equivalent conductance of APM at 25℃ is 수식 The calculated values from the equation are somewhat rough consistent with measured values for solutions more diluted than 10^-4 eq/l of APM.

無煙炭 燃燒에 關한 硏究

權利默,韓相準 이화여자대학교 한국문화연구원 1964 韓國文化硏究院 論叢 Vol.5 No.-

In the study we devised a gravimetric CO determination method with a CO oxidizing catalyst, which enable us to make a rapid and more precise determination of CO than volumetric and Orsat method we used before. On the combustion conditions, the counter wind, thick briquette later, small size of chimney and damper were the great factors of CO origination in flue gas of household briquette furnace. The direction of chimney should be south in winter at north hemispere, and the size be greater than 7.5cm for 19 holes briquette furnace. The appropriate size of primary air hole seems to be 2-4cm for 19 holes briquette furnace. The CO elimination effect of which top to bottom spread combustion method furnace was remarkable, but the endurance of furnace and sticking of two brequette is troublesome factors for practicle use. The CO origination and elimination effect of briquette compounding materials (minerals and chemicals) was much complicated. For the mineral, silica, alumin, aluminosilicate, magnesia, iron oxide ore and cupric oxide are the principle effecting (positive or negative) substances. The effect of these minerals are not only chemical but physical effect as such variation of rate of diffusion and flow of gases through briquette and ash layer, owing to vitrification, expansion and cracking of briquette are also involved. Compounding such materials into briquettes should be investigated for each coal species which is differ in its character and original mineral consititute. The positive effect compounding ingredients and its most appropriate ratio for the most part of anthracite coal species were acid clay 2-5% bentonite 2-5% (week effect), NaOH 0.1-0.5%, Na_2CO_3 0.1-0.5%, Limonite or Hematite 1-7%, CuO(calcinated copper minerals)-Limonite-NaOH 1-9%.

無燃炭 燃燒에 관한 硏究(III)

權利默,韓相準 이화여자대학교 한국문화연구원 1960 韓國文化硏究院 論叢 Vol.2 No.-

In this Study we devised a method of CO determination in the combustion gas mixture. CO content can be determined quickly by converting it into CO_2 with a catalyst, Fe_2O_3-MgO-Cr_2O_3-K_2O-Al_2O_3. The mixed catalytic system was found to be an excellent one for she rapid oxidation of CO. Its catalytic activity could be kept unchanged up to 70 hours under the reaction conditions. We have also found that the addition of Hematite or Limonite, Pyrolusite, crude sodium manganate, sodium hydroxide and quicklime into anthracite briquette promoted the fuel effect such as calorie output, clinker forming. The remarkable elimination of CO gas from the combustion gas was also observed. About 70% of the poisonous CO gas which is formed during combustion is converted into CO_2. This fact means the cut down of the CO content in the gas mixture below the safety level for the human body.

탄화수소의 수증기개질 촉매에 관한 연구

권이묵,김태순,Lee Mook Kwon,Tae Soon Kim 대한화학회 1971 대한화학회지 Vol.15 No.2

In this study, several nickel catalysts for the steam-hydrocarbon reforming process were prepared from various nickel salt, magnesium oxide, alumina and kaolinite. The activity and strength of the catalysts were investigated. 1. The proper composition of the calcined catalysts are: NiO (5-15%)-MgO(10-20%)-$Al_2O_3$(10-40%)-Kaolinite(50-80%). 2. The admixed or cosedimented ingredients of the catalysts was pelletized and calcinated at 1000 or $1150^{\circ}C$. Calcination at $1150^{\circ}C$ for an hour was optimum. 3. The water to oil ratio (W/O) for reforming of hexane should be above 7 mole/mole. As the W/O increases, more carbon dioxide and hydrogen, but less carbon monoxide was produced. Also carbon deposition become lessen at higher W/O. 4. Maximum conversion had attained at about $850^{\circ}C$. As the reaction temperature increases, more carbon monoxide and hydrogen, but less carbon dioxide and lower hydrocarbon was produced. 5. The percent conversion at $850^{\circ}C$ was about 80%, using a catalyst which the nickel oxide content are 5%.

ZSM -5 및 Silicalite -Ⅰ 의 합성

김건중,권이묵 한국화학공학회 1988 NICE Vol.6 No.3

ZSM - 5 및 Silicalite - 1의 합성(1)

김건중,권이묵 한국화학공학회 1988 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.26 No.3

Zeosil 77과 sodium silicate 溶液을 silica源으로 사용하여 ZSM-5 및 Silicalite-I을 水熱合成하였으며, 反應基質의 組成, 熟成時間, 反應溫度 및 反應時間 등이 結晶生成에 미치는 영향을 검토하였다. ZSM-5는 反應基質의 組成이 酸化物의 몰比로서 Na₂O/SiO₂ = 0.05∼0.2, SiO₂/ Al₂O₃ = 30∼∞, H₂O/Na₂O = 200∼600 및 TPA+/SiO₂ = 0.12인 領域에서 高純度로 生成되었다. ZSM-5型 zeolite의 合成에 있어서는 室溫熟成時間이 2일까지 길어짐에 따라 誘導期間 및 結晶化時間이 단축되고, 生成된 結晶의 크기도 작아짐을 알 수 있었다. Silica源으로서 微粉末인 Zeosil만을 사용한 경우보다 sodium silicate solution에 Zeosil을 보충한 때가 더욱 빠른 結晶化速度를 나타내었다. Sodium silicate와 Zeosil을 混用하여 ZSM-5(SiO₂/Al₂O₃ = 68)를 合成하였을 때와 Silicalite-I을 合成할 때의 核生成過程 및 結晶化過程에서 요하는 活性化에너지는 각각 54,22KJ/mole(ZSM-5) 및 40,15KJ/mole(Silicalite-I)이었으며, Zeosil만을 silica源으로 사용했을 경우의 活性化에너지는 각각 60,38KJ/mole(ZSM-5) 및 40,26KJ/mole(Silicalite-I)이었다. ZSM-5 and Silicalite-I were synthesized hydrothermally using Zeosil 77 and sodium sillicate solution as silica sources, and the effects of reactants composition, aging time, reaction temperature and reaction time on the zeolite crystallization were investigated. It was established that the oxides molar ratio of substrates resulting ZSM-5 type zeolite in high purity were as follows; Na₂O/SiO₂ = 0.05-0.2, SiO₂/Al₂O₃ = 30-∞, H₂O/Na₂O = 200-600, TPA+/SiO₂ = 0.12. For the ZSM-5 type zeolites, the induction period, and reaction time and the obtained crystal size were found to decrease progressively as the aging time is increased up to 2 days. At the same time, the higher rates of crystallization were obtained when sodium silicate solution in conjunction with Zeosil was used as the silica source than Zeosil alone. The activation energies for the nucleation and those for the crystal growth step of ZSM-5 and Silicalite-I were 54,22KJ/mole(for ZSM-5) and 40,15KJ/mole(for Silicalite-I) when sodium silicate solution blended with Zeosil was used as the silica source. On the other hand, the activation energies using Zeosil as the silica source were 60,38KJ/mole(for ZSM-5) and 40,26KJ/mole (for Silicalite-I), respectively.

산성용액 내에서${\alpha}-Fe_2O_3$의 용해에 대한 환원성 염의 효과

이정익,권이묵,Jeong-Ik Lee,Lee-Mook Kwon 대한화학회 1983 대한화학회지 Vol.27 No.3

${\alpha}-Fe_2O_3$의 HCl 또는 $H_2SO_4$에 의한 용해반응에 있어서 금속염의 첨가효과를 분광광도법과 중량법으로 검토하였다. 환원성 금속염은 현저한 반응촉진 효과를 보이나 비환원성 금속염은 부의 효과를 나타내었다. $FeCl_2$와 같은 환원성 금속염을 첨가한 경우에 ${\alpha}-Fe_2O_3$의 용해속도가 크게 촉진되는 것은 $Fe^{3+}$ 와 $Fe^{2+}$ 사이에 chloro-brige가 형성되어 전하이동이 일어나면서 ${\alpha}-Fe_2O_3$ 표면의 격자에너지를 감소시키기 때문인 것으로 추측된다. 이 전하이동으로 인한 ${\alpha}-Fe_2O_3$ 표면의 격자 에너지 변화가 반응의 활성화에너지 변화와 대응된다고 보면 약 0.36e의 부분전하가 $Fe^{3+}$ 쪽으로 옮겨간 것으로 계산되었다. Effect of metallic salts added to the ${\alpha}-Fe_2O_3-HCl\;or\;{\alpha}-Fe_2O_3-H_2SO_4$ reaction systems were investigated by colorimetric and gravimetric determinations. While reductive salts exhibited remarkably enhanced reaction rate, non-reductive salts showed inhibitive results. We supposed that the improvement of dissolution rate of ${\alpha}-Fe_2O_3$ by the addition of $FeCl_2$, a reductive salt, to the ${\alpha}-Fe_2O_3-HCl$ system can be attributed to the formation of chloro-bridge between $Fe^{3+}\;and\; Fe^{2+}$, and therefore some partial electronic charge transfer from $Fe^{2+}\;to\;Fe^{3+}$ on the surface of ${\alpha}-Fe_2O_3$ will be easily achieved through the bridged bond. The transferred charge to the surface will reduce the positive charge of initial $Fe^{3+}$, and also result to reduce the lattice energy of that site. Assuming tothat there is a linear relationship between the lattice energy change and the change of activation energy of the reaction system, the transferred partial electronic charge to $Fe^{3+}$ of ${\alpha}-Fe_2O_3$ surface was calculated to be ca. 0.36e.

Ion 交換膜에 依한 Thorium溶液 電解濃縮의 速度論的 硏究

權東淑,權利默,韓相準 이화여자대학교 한국문화연구원 1960 韓國文化硏究院 論叢 Vol.2 No.-

Although the possibility of the use of ion exchange membranes for the electrolytic concentration has been known for about 10 years, little information was available for the case of thorium solution. The relative importance of the factors influencing the electrolytic concentration were also kept unknown. Many studies, however, have been reported about the concentration and separation of the salts in the sea water by using several ion exchange membranes. This method has been developed to be applied for the industrial processes. This study has been undertaken to separate the thorium from monazite sand by the ion exchange membranes. Monazite is a phosphate mineral of varing compositions and it is one of the abundant minerals among the so-called atomic fuel resources which can be available in this country. In this paper, we report the kinetic studies for the concentration process of the thorium solution through membrane and propose a newly devised rate equation. 수식 Here, E and n2 are the membrane voltage and the number of moles of the salt in the concentration compartment of the cell, respectively. "n" is the sum of "n1" and "n2" "n1" is the number of moles of salt in the desalting compartment. The parameters and calculated values were summarized in table 1 and 2. The percentage of the concentration degree has variety from 70 to 97 percent. It was assumed that the concentration efficiency is not only dependent upon the temperature but also the terminal voltage, V. The activation heat for the ion exchange velocity of the membranes is found to be 4.15 kcal/mole and this value shows an good agreement with the already observed values for the ion exchange resins. The activation entropy obtained shows a fairly large negative value (-40.46 e.u.) and the negative entropy is often observed in the flow processes.