• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.379-384
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• 1996

제올라이트 4A와 AW-500을 2:3으로 혼합하여 충진한 제올라이트탑을 이용하여, 열 발생 핵종인 Cs과 Sr을 동시에 제거하는 연구를 수행하여 얻어진 결과는 다음과 같다. 제올라이트 4A와 AW-500의 입도가 작을수록 Cs 및 Sr의 파괴점까지의 유출량은 급격히 증가하였고, Sr의 파괴점은 모의폐액의 유량 및 온도에 많은 영향을 받으나, Cs의 파괴점은 모의폐액의 온도에 무관하고, 유량에 미미한 영향을 받았다.

• Clean Technology
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• v.22 no.3
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• pp.161-167
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• 2016

Catalytic combustion of benzene over various metal cation-exchanged zeolites has been investigated. Y(4.8)-type zeolite showed the highest activity among the used zeolites and Cu/Y(4.8) catalyst also showed the highest activity among metal cation/ Y(4.8) zeolites. The catalytic activity increased according to the amount of adsorbed oxygen acquired from O₂ TPD results. The catalytic activity also increased with an increase of Cu cation concentration on Cu/Y(4.8) catalysts. The conversion of benzene on the combustion reaction depended on not benzene concentration but the oxygen concentration. In addition, the introduction of water into reactants decreased the catalytic activity.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.3
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• pp.95-101
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• 2007

The synthesis of NaA zeolite membrane on a porous alumina support from clear solution by using hydrothermal reaction was investigated. Effects of reaction temperature, reaction time and seeding for transformation of zeolite A membrane and powder which are produced in the reactor were monitored through X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). The transformation process of producing Zeolite A membrane starts from the formation of the compact and continuous membrane on the surface of porous support from clear solution. The large Zeolite A poly-crystal was then farmed through the dissolution process. Finally, the process was advanced from sodalite to amorphous. In case of powder, sodalite is formed in the early stage of reaction because of surrounding space difference between membrane and powder crystal. Discrete surrounding space of powder crystal makes easy to transform to sodalite. From Zeolite A to amorphous through transformed product was rapidly advanced at high temperature while the membrane with somewhat low coverage was obtained at low temperature. A compact and continuous zeolite A membrane was synthesized at $120^{\circ}C$ in 12-hour period.

• Clean Technology
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• v.24 no.1
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• pp.21-26
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• 2018

The coal is a useful industrial resource for a long time. However, coal waste is generated by the mining process. Coal wastes are the main cause of pollution in the surrounding environment, and the amount of coal waste is set at hundreds of millions of tons. Significant amounts of these components in the coal waste are $SiO_2$ and $Al_2O_3$, which is also the main source of zeolites useful in various industries. This study is that the synthesis-zeolite was prepared from coal waste and properties and adsorption performance of synthesis-zeolite were compared with commercial zeolite. The synthesis-zeolite is showed similar properties to the commercial zeolite and also showed excellent adsorption performance against atmospheric pollution induced gases ($CO_2$, Toluene, $SO_2$, etc).

• Membrane Journal
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• v.27 no.6
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• pp.469-476
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• 2017

Membrane separation is a technology of low energy consumption. Membranes made of zeolites are of great interest because their fixed and open pores in the size of small molecules inside crystalline structures allow separation processes under harsh conditions. While zeolite NaA (LTA-type) is industrially used for dewatering of organic solvents, its pore size and thermal and hydrothermal stability can be tuned by exchange of framework and extra-framework elements. SOD with pores of only 0.28 nm is of great interest for $H_2$- und $H_2O$-separation and also can be tuned by ion exchange. Zeolites open the opportunity to create membranes of adapted separation behavior for small molecules in conditions of surrounding technical processes.

• Polymer(Korea)
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• v.28 no.5
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• pp.374-381
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• 2004

Gas permeability of low density polyethylene (LDPE) film containing zeolite powder for $CO_2,\;O_2$ and $N_2$ were investigated. Zeolite powders modified by cations or surfactant were compounded with LDPE to produce $20 wt\%$ masterbatch. After blending the masterbatch with LDPE, zeolite filled films were prepared by the blown film process. Finally, the composite films containing zeolite loadings of 0, 3,5, and $10 wt\%$ were produced. A gas permeability apparatus based on the variable volume principle was designed to analyze the characteristics of films. Experiments showed a general trend that gas permeabilities first decreased and then increased as the zeolite content was increased. Surfactant modified zeolite showed a better interfacial adhesion with the matrix, but the film did not show a discernible difference in gas permeability compared with the other modified films. The difference of temperature dependences in the gas permeabilities of composite films was slightly smaller than that of LDPE film.

• Journal of the Korean Geophysical Society
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• v.4 no.4
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• pp.251-256
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• 2001

Korean natura1 zeolite with fe1dspar and illite as impurities was purified by an air c1assification method. X-ray powder diffraction ana1yses showed that the air c1assification effectively separated zeolite and impurities, and reduce the amount of impurity of the natura1 zeolite. The zeolite with air c1assification was treated with 1N NaOH solutions at temperatures at 100, 150, 200 ℃ for 17hours. The obtained hydrotherma1 treatment of phase change to philli1site and ana1cime from mordenite and clinopti10lite.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.213-218
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• 1994

제올라이트 분말을 기본재료로 하는 전기유변유체의 전기 및 유변학적 특성이 연구되었다. 전기장 인가시 높은 한계응력을 얻기 위하여 비교적 유전상슈가 큰 5종류의 유전유체를 선택하여 제올라이트 분말과 혼합하여 전기유변유체를 준비하였다. Couette형 rheometer를 이용하여 유변유체의 한계응력을 인가된 전기장 및 온도의 함수로서 측정하였다. 이중 chlorinate hydrocabon oil과 제올라이트 분말을 혼합한 전기유변유체의 한계응력은 6KPa(E=4KV/mm, T=$25^{\circ}C$)로서 최대치를 기록하였다. 측정된 한계응력은 온도가 상승하면 점차 감소하는 반면 전류밀도는 온도에 따라 증가하였다. 전류밀도에 대한 Arrhenius 그라프에서 전기전도에 대한 활성화 에너지는 약 0.7eV였으며 이는 제올라이트 분말에 포함된 $Na^{+}$ 이온의 확산에 기인하는 것으로 분석되었다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.215-219
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• 2003

The technology to fix a molten LiCl waste, which would be generated from the process to convert spent fuel to metal, into zeolite and then make a final waste form is doing developed. The XRD results of salt-loaded zeolites with different mixing ratios showed that all zeolites transformed from zeolite A type into Li-A type, or also Sodalite type as a minor phase for some conditions. The optimum LiCl-to-zeolite ratio to bring a minimum free salt was 1.0 when the molten LiCl waste contained Cs and Sr.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.24-29
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• 1994

The zeolite X was prepared from the Korean natural clinoptilolite, which contains some mordenite. Thermal treatment removed the clinoptilolite structure from the ore remaining mordenite. The natural clinoptilolites dealuminated with 2N-8N HCI solution and/or thermal treatment were mixed with NaCl, $NaAlO_2$ and NaOH, and reacted to zeolites X at $95^{\circ}C$ for 12~36 hrs. Maximum yield of NaX was obtained for the reactant mixture of 25 gr of natural zeolite acidtreated with 8 N HCI, together with 3.5g NaCl, 8g $NaAlO_2$ and 50 ml of 6N NaOH at $95^{\circ}C$, for 24 hrs.