• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.6
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• pp.238-242
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• 2016

The effect of the alkali, alkali earth metal elements on selective catalytic reduction(SCR) catalyst deactivation behavior were investigated in terms of microstructure, surface area, pore volume and De-NOx test. Poisoned SCR catalyst were manufactured by injection of $K_2CO_3$, $Na_2CO_3$, $Ca(CH_3COO)_2{\cdot}H_2O$, $C_4H_6MgO_4{\cdot}4H_2O$, $H_3PO_4$ solutions in the new SCR catalyst at $350^{\circ}C$ for 6 hours. New and poisoned catalysts surface were similar. But specific surface area, pore volume decrease from Na, Mg, K, Ca, P compared to new SCR catalyst. Especially, Na poisoned catalyst surface area and pore size extremely decreased by $10.20m^2/g$, $0.061cm^2/g$. De-NOx test results of new and poisoned catalysts at $150{\sim}450^{\circ}C$ indicated that alkali metal (K, Na) poisoned SCR catalysts have the lowest De-NOx efficiency, alkali earth metal poisoned SCR catalysts (Ca, Mg) De-NOx efficiency are higher than alkali metal poisoned SCR catalysts. P poisoned SCR catalyst De-NOx efficiency is similar new SCR catalyst. It were considered that physical deactivation of SCR catalyst was affected by SCR catalyst surface area and pore volume change.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.524-529
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• 1995

The separation efficiency of metal ions by using silica gel bonded 15-crown-5 (SGBM) has been determined by column chromatography in aqueous solution at pH 1. Bindinng constants and separation factors for several SGBM-Metal interactions were measured in aqueous solution. The order of these binding constants and separation factors with metal ions was Li(Ⅰ) < Sr(Ⅱ) < Na(Ⅰ) < Cu(Ⅱ) < Mg(Ⅱ) < K(Ⅰ) < Ca(Ⅱ) < Bi(Ⅲ) < Sb(Ⅲ). These results were explained in terms of the size effect and electron density effect. This experimental results showed good efficiency for separation of $Sb^{3+}$ from mixtures of alkali, alkaline earth metal ions, and $Cu^{2+}$ in aqueous solution.

• Journal of Environmental Health Sciences
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• v.14 no.1
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• pp.1-9
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• 1988

석탄유도가스에 포함된 황화수소를 제거시킬 흡착제를 개발하기 위하여 알칼리 토금속, 천이원소 및 아연의 이온반경보다 이온반경이 작은 금속산화물을 산화아연에 첨가시켜 다공성 흡착제를 제조하였다. 600$\circ$C에서 이들 첨가시료를 2.09vol.% 황화수소와 질소가스 혼합기체로 반응시켜 초기속도를 측정하고, 같은 온도에서 사용된 흡착제를 공기로 재생시켰다. 사용된 금속산화물 첨가 흡착제중에서 CaO, TiO$_2$, $Fe_2O_3$, CuO, $Ga_2O_3$ 및 Si$_2$O가 ZnO 흡착제의 초기속도를 증가시켜 첨가제로 사용할 수 있음을 보였다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.227-230
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• 2008

본 논문은 알칼리토금속계인 마그네슘 등의 수화 반응에 수반되는 반응열과 전기화학적 작용을 이용하여 버너와 같은 화기를 이용하지 않고 야외에서 생수 등을 간접가열 하여 커피, 컵라면, 분유, 피자등의 음식을 가열 할 수 있는 발열제품을 개발하는 데이터를 얻었다. 마그네슘과 금속계 화합물을 혼합하여 tea bag에 넣어 셀 형태로 만들어 발열효과를 높이기 위해 특수시험관의 재질 및 두께의존성, 발열제 양과 혼합물질에 따른 온도특성 등을 확인하였다. 발열제에서 발생되는 열의 효율적인 전달과 포장 재질의 선정 및 휴대의 간편성 등을 고려하여 타당성을 검증하였다.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.671-677
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• 2016

The impregnated alkali metal (Na, K), and the alkali earth metal (Ca, Mg) activated carbons were produced from the bamboo activated carbon by soaking method of alkali metals and alkali earth metals solution. The carbonization and activation of raw material was conducted at $900^{\circ}C$. The specific surface area and the pore size distribution of the prepared activated carbons were measured. Also, NO and activated carbon reaction were conducted in a thermogravimetric analyzer in order to use for de-NOx agents of the used activated carbon. Carbon-NO reactions were carried out in the nonisothermal condition (the reaction temperature $20{\sim}850^{\circ}C$, NO 1 kPa) and the isothermal condition (the reaction temperature 600, 650, 700, 750, 800, $850^{\circ}C$, NO 0.1~1.8 kPa). As results, the specific volume and the surface area of the impregnated alkali bamboo activated carbons were decreased with increasing amounts of the alkali. In the NO reaction, the reaction rate of the impregnated alkali bamboo activated carbons was promoted to compare with that of the bamboo activated carbon [BA] in the order of BA(Ca)> BA(Na)> BA(K)> BA(Mg) > BA. Measured the reaction orders of NO concentration and the activation energy were 0.76[BA], 0.63[BA(Na)], 0.77[BA(K)], 0.42[BA(Ca)], 0.30 [BA(Mg)], and 82.87 kJ/mol[BA], 37.85 kJ/mol[BA(Na)], 69.98 kJ/mol[BA(K)], 33.43 kJ/mol[BA(Ca)], 88.90 kJ/mol [BA(Mg)], respectively.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.373-378
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• 1996

알칼리 및 알칼리토금속(Cs,Rb,Ba,Sr), 전이감속원소(Zr,Fe,Mo,Ni,Pd,Rh), 란탄족 (La,Y,Nd,Ce,Eu.) 및 MA(Np,Am)등 17개 원소로 구성된 질산매질의 모의 방사성용액에서 옥살산에 의한 란탄족과 MA(Minor Actinide)의 공침전 연구를 수행하였다. 옥살산농도 0.5M에서 질산농도의 영향과 아스코빅산 첨가에 따른 원소들의 침전율이 조사되었다. 각 원소들의 침전율은 질산농도에 따라 약간 감소하였으나 란탄족과 MA는 99%이상 공침전되었다. 아스코빅산이 첨가되는 경우 Pd이 금속으로 환원침전되고 Mo.Fe,Ni.Ba의 경우는 침전율이 10∼20% 감소하는 것으로 나타났으나 기타원소들에 대해서는 영향이 나타나지 않았다. Pd의 환원침전은 질산농도 1.0M미만에서 일어났으며. 아스코빅산 농도가 0.01M∼0.02M 부근에서 최대로 나타났다. 하이드라진이 아스코빅산과 같이 첨가될 때 Pd의 환원침전을 억제하는 역할을 하였다.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.857-864
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• 2005

Dealuminated and alkali/alkaline-earth metal exchanged Y-type and ZSM-5 zeolites were prepared as catalytic materials. Comparing with the composition of starting material, the magnitude of Si/Al ratio was increased after dealumination and cation exchange process. The ratio of Si/Al on surface was appeared to be larger than that in bulk. The destruction of basic frame in catalysts observed was understood to be due to a detachment of aluminum, which results in reducing framework while increasing non-framework. This phenomenon becomes more serious with increasing time of steam treatment and even more significant for the cation exchanged catalysts. The desorption peaks of the NO-TPD profiles taken after dealumination and cation exchanged Y-type and ZSM-5 zeolites shifted to the low temperature region. It was also found that the longer the steam treatment time, the degree of shift toward low temperature region was increased. The catalytic activities are dependent on the nature of cation exchanged, the ratio of Si/Al and the ratio of framework/non-framework by a change in basic frame.

• Journal of the Korean Ceramic Society
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• v.13 no.4
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• pp.15-19
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• 1976

Mutual interferences of alkali and alkali-earth metals in atomic absorption were examined. For determination of Na or K interfering elements increase the absorbancy, and for Ca or Mg decrease. Since influences of coexisting elements become nearly constant by addition of large amount of same coexisting element, could be use mixed standard solution for alkali or alkali-earth metal determination in the presence of other alkali and alkali-earth metals. The metals can be readily incorporated into scheme of rapid silicate analysis. Precision and accuracy are good.

• Journal of the Korean Chemical Society
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• v.27 no.3
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• pp.208-212
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• 1983

The stability constants for the complexes formed between dibenzo-18-crown-6 compound and alkaline earth metal cations in dimethylsulfoxide, dimethylformamide, and acetonitrile have been obtained by conductometry at $25{\circ}C\;and\;35{\circ}C$respectively. The stability constants were increased in order of $Ca^{2+} in any solvent, and the magnitudes were found to be reversely proportional to the solvent donicities. The result could be understood in terms of ion-cavity radius concept, solvent basicity, and solvation of the cations.

• Applied Chemistry for Engineering
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• v.2 no.3
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• pp.270-278
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• 1991

Carboxymethyl chitin(CM-chitin) was prepared by the reaction of alkali chitin with monochloroacetic acid in isopropyl alcohol. According to the pH variation, the adsorptivity of this chelating polymer to the alkali-earth metal ions such as $Ca^{2+},\;Mg^{2+}$, $Sr^{2+}$, $Ba^{2+}$ ions was determined by batch method. The adsorption tendency of this chelating polymer to most metal ions was increased with the increase of pH. The highest degree of adsorption was observed toward $Ca^{2+}$ ion among the alkali-earth metal ions. The selectivity adsorption property toward $Ca^{2+}$ ion was examined in the solution of $Ca^{2+}$ and $Mg^{2+}$ ions, and it was observed that CM-chitin showed excellent selectivity to $Ca^{2+}$ ion than $Mg^{2+}$ ion. $Mg^{2+}$ ion bound to CM-chitin molecule in the presence of $Ca^{2+}$ ion owing to low equilibrium constant. In the adsorption experiment of $Ca^{2+}$ and $Mg^{2+}$ ions to the CM-chitin under coexistence of $Na^+$ and $K^+$ ions, it observed that adsorptivity of only $Ca^{2+}$ ions was not affected by these monovalent cations.