• 한국광물학회지
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• 제20권4호
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• pp.267-275
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• 2007

생활폐기물 소각재를 용융시켜 제조한 슬래그에는 제올라이트 합성에 영향을 주는 많은 불순물이 포함되어 있다. 이러한 불순물들은 원하는 제올라이트 합성을 방해하며, 수율과 순도를 저하시킨다. 용융 슬래그에는 특히 $Fe_2O_3$, FeO 그리고 CaO가 많이 포함되어 있다. 이런 불순물들을 제거하기 위해 염산으로 슬러리의 초기 pH를 1, 3, 5 그리고 7로 하여 각각 처리하였다. 실험결과, 슬러리의 초기 pH가 낮아질수록 $SiO_2,\;Fe_2O_3,\;TiO_2$ 등의 함량은 증가되었으나, $Al_2O_3,\;FeO,\;CaO,\;Na_2O,\;K_2O,\;MgO$ 등의 함량은 감소되었다. 염산처리한 슬래그를 NaOH 용액과 함께 $80^{\circ}C$에서 반응시킨 결과, 슬래그, pH 7과 pH 5에서 처리한 시료로부터는 토버모라이트(tobermorite)가, pH 3과 pH 1에서 처리한 시료로부터는 Na-P1형과 Na-X형 제올라이트가 생성되었다. 또한 CaO가 제올라이트 합성을 방해한다는 것을 확인하였다.

• 한국세라믹학회지
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• 제26권5호
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• pp.705-711
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• 1989

The glass-ceramics was prepared with the scoria(CaO-MgO-Al2O3-SiO2 system) of the locally occurring volcanic ejecta containing 10-13w/o of (FeO＋Fe2O3) by melting at 140$0^{\circ}C$ for 4 hours and thermally treated for nucleation and crystallization. The sucrose was added to the scoria to adjust the Fe2+/Fe3+ ratio during the melting process. The addition of 1-2w/o of sucrose showed the glass-ceramics body with the finest particle developed and dispersed over the entire range. It is concluded that the impurity content of iron oxide and titanium oxide play the most-influencial effect on the crystallization. When 1-2w/o of sucrose was added to the scoria, the value of Fe2+/Fe3+ ratio was 0.93-1.32 and showed the best result of crystallization. The nucleation temperature and time were calculated by the measurements of exothermic peak temperatures of DTA for quenched and thermally treated glasses. The nucleation temperature of scoria glass without the addition of sucrose was estimated as 75$0^{\circ}C$, but the addition of sucrose by 2w/o showed the nucleation temperature 6$25^{\circ}C$. The nucleation time was calculated with the same DTA curves. The nucleation times estimated were about 150min. for both of glasses without and with sucrose added. Finally, the activation energies for crystallization were calculated with the DTA data. The calculated activation energies were 143 Kcal/mole for the glass without addition of sucrose and 90Kcal/mole, 87Kcal/mole, 85Kcal/mole and 71Kcal/mole for the glasses of 1w/o, 2w/o, 3w/o and 4w/o addition respectively.

• 한국세라믹학회지
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• 제53권2호
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• pp.139-144
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• 2016

The dependence of the microwave dielectric properties of the glass-ceramic composite $0.9CaMgSi_2O_6-0.1MgSiO_3$ on the crystallization behaviour was investigated as functions of the $TiO_2$ content and heat-treatment temperature. The crystallization behaviour of the specimens was evaluated via a combination of the Rietveld and reference-intensity ratio methods. For specimens with a $TiO_2$ content of up to 1 wt.%, a monoclinic diopside phase was formed, whereas a secondary $TiO_2$ phase was formed with further increases in the $TiO_2$ content. The quality factor (Qf) of the specimens was strongly dependent on the degree of crystallization. The highest Qf value was obtained with a $TiO_2$ content of 0.5 wt.%, which was improved by increasing the heat-treatment temperature. The dielectric constant (K) was affected by the size of the crystallites and the $TiO_2$ content. The temperature coefficient of the resonant frequency (TCF) was nearly constant for all of the specimens, regardless of the $TiO_2$ content or heattreatment temperature.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.75-78
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• 2002

The dielectric properties for Ni electrode multilayer ceramic chip capacitor for Y5V has been studied with $(Ba_{0.93}Ca_{0.07})_m(Ti_{0.82}Zr_{0.18})O_2+MnO_2$ 0.2wt%, $Y_2O_3$ 0.18wt%, $SiO_2$ 0.15wt%, glass frit 1 wt% composition. The m ratio in the range of 1.006 ~ 1.012 have dielectric constant 9,500 ~ 14,500 and insulation resistance 390 ~ 460 $G{\Omega}$. Using the dielectrics, nikel electrode multilayer chip capacitor with Y5V, 104Z in EIA 0603 size specific capacitance were developed.

• 보존과학회지
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• 제8권1호
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• pp.10-15
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• 1999

강릉 보광리 도요지에서 출토된 분청 도편의 성분과 미세구조의 특징을 EDS부착의 주사전자현미경과 X선 회절분석기, 열팽창측정기를 이용하여 조사하였다. 도편의 태토 성분은 $SiO_2(73-78\%),\;Al_2O_3(13-16\%)$, $RO{\cdot}R_2O(4-5\%,\;R=Ca,\;Mg,\;Na,\;K),\;R_xO_y(3-6\%,\;R=Fe,Ti)$로 구성되어 있으며, $SiO_2$의 양은 많은 편이나 $Al_2O_3$의 양은 적은 편이었다. 유약은 CaO 함량이 $21-30\%$로 높은 것으로 보아 석회계열의 유약으로 생각된다. 또한 도편의 소성온도는 $1150^{\circ}C$부근의 온도로 추정된다.

• 박물관보존과학
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• 제13권
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• pp.45-49
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• 2012

창원 다호리 유적 6호분에서 출토된 유리구슬편 14점에 대하여 과학적인 분석을 실시하였다. 유리편은 대부분 감청색의 투명한 유리로 원형의 기포들이 일정한 방향으로 나열되어 있다. SEM/EDS 분석결과 유리편은 모두 포타쉬유리군(K₂O-SiO₂)이며 CaO 및 Al₂O₃의 함량은 모두 5%이하인 LCA(Low CaO, Low Al₂O₃)계 유리로 확인되었다. 또한 포타쉬원료는 식물제를 정제하거나 광물(초석, KNO₃)을 사용한 것으로 판단되며 감청색을 내는 발색제로 작용하는 성분은 CuO의 영향이 큰 것으로 판단된다.

• 한국세라믹학회지
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• 제18권2호
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• pp.112-118
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• 1981

A study was made on the processing of domestic blast furnace slag by flotation and chemical purification for the use of slag as a raw material in making soda lime glasses. Feasibility study has been made for the use of reprocessing slag as a source material for both coloring and chemical components (such as CaO, $Al_2O_3$, MgO and etc.) in the glass making process. Chemical composition of chemically purified slags ranges; $SiO_2$ 34.5~37.5, $Al_2O_3$, 16.2~14.1, $Fe_2O_3$ 0.33~0.14, CaO 34.5~38.8, MgO 4.0~5.2, NmO 0.16~0.39, $TiO_2$ 0.23~0.35, S 0.08~0.42, ignition loss 3.3~8.4 and others 0.48~0.51%. It was found that either amber or greenish color could be easily obtained with the addition of salg up to 24%, however the slag addition to glass batches much impaired the transmitancy of glass products, thus a glass made with 7% slag addition showed 82% in transmitancy value at 510 nm.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1076-1078
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• 2004

In this paper, we report $Eu^{2+}$ activated green phosphor $Ba_2CaMgSi_2O_8:Eu^{2+}$. This phosphor absorbs ultroviolet radation and emits a green visible light. The phosphors were synthesized by conventional solid state reaction method. Reagent grade $BaCO_3$, $CaCO_3$, MgO, $SiO_2$, $Eu_2O_3$ were used as raw materials. The raw materials were mixed thoroughly with an appropriate amount of ethanol in an agate mortar and then dried at 90 $^{\circ}C$ for 2 hours. The mixture was sintered at 900 $^{\circ}C$ for 2 hours and reheated at the mild reducing atmosphere 5% $H_2$ gas mixed with 95% $N_2$ gas at about 900 $^{\circ}C$ to 1250 $^{\circ}C$ for 2 hours. The photoluminescence spectra of the phosphor powders were measured by a fluorescent spectrophotometer. The crystal structure of phosphor powders were investigated by X-ray diffractometer.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 춘계학술대회 발표 논문집
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• pp.97-100
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• 2004

We report $EU^{2+}$ activated green phosphor $Ba_{2}CaMgSi_{2}O_{8}:Eu^{2+}$. The phosphor absorbs ultroviolet radation and emits a green visible light. The phosphors were synthesized by conventional solid state reaction method. The high purity $BaCO_3$, $CaCO_3$, MgO, $SiO_2$, $Eu_{2}O_{3}$ were used as raw materials. The raw materials were mixed thoroughly with an appropriate amount of ethanol in an agate mortar and then dried at $90^{\circ}C$ for 2 hours. The mixture was sintered at $900^{\circ}C$ for 2 hours and reheated at the mild reducing atmosphere 5% $H_2$ gas mixed with 95% $N_2$ gas at about $900^{\circ}C$ to $1200^{\circ}C$ for 2 hours. The photoluminescence spectra of the phosphor powders were measured by a fluorescent spectrophotometer. The crystal structure of phosphor powders were investigated by X -ray diffractometer.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1165-1166
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• 2006

An experiment was carried out to investigate the effect of Ba Stearate as a reducing agent on the magnetic and physical properties of anisotropic $BaFe_2-W$ type ferrite magnets. It was found that the magnetic properties of $BaO{\cdot}8.5Fe_2O_3$ were improved by adding 0.3 wt% of Ba Stearate, 0.5 wt% of $SiO_2$, and 0.5 wt% of CaO together. The optimum conditions for making magnets were as follows; semisintering condition: $1350^{\circ}C{\times}4.0$ h in nitrogen gas atmosphere, drying condition: $180^{\circ}C{\times}2.0$ h in air, sintering condition: $1160^{\circ}C{\times}1.5$ h in nitrogen gas atmosphere. Magnetic and physical properties of a typical sample were $J_m$ = 0.46 T, $J_r$ = 0.43 T, $H_{cJ}$ = 182.3 kA/m, $H_{cB}$ = 177.2 kA/m, $(BH)_{max}$ = 33.8 kJ/$m^3$, $T_C$ = $495^{\circ}C$ and $K_A$ = $2.65{\times}10^5\;J/m^3$ and $H_A$ = 1332 kA/m.