• Journal of the Korean Ceramic Society
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• v.41 no.2
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• pp.158-164
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• 2004

This study is to analyze the characteristics of typical Korean wood ashes from twelve trees, oak tree needles and pine bark, which are common in the area, and to suggest their applications in ash glaze making. The chemical analysis of the ashes shows that the main component of wood ash is CaO while wood bark ash consists of $SiO_2$, and leaf ash consists of CaO and $SiO_2$. The results of the study are as follows: Ashes made from the wood of Acasia, Popular and Jujube contained relatively high amounts of Fe$_2$ $O_3$ and MgO compared to other tree ashes. The ashes had yellowish green color glaze. From the result of W analysis they presented the highest chroma. Therefore these ashes are good for making transparent glaze. From the result of W analysis Grapevine, pear and oak wood ashes containing the highest amounts of Fe$_2$ $O_3$, MgO, P$_2$O$\_$5/ and MnO presented yellowish green color glaze compared to other ashes are suitable for making opaque glazes because of their showing stable and opacity phenomena. Pine tree, Platanus and Zelkova wood ashes consist of high amounts of CaO and P$_2$O$\_$5/ compared to other tree ashes. So they showed the most vivid and bluish green color glaze among 12 ashes. Therefore, they would make a good celadon glaze. Birch, oak and chestnut tree ashes have high content or MnO which affects on glaze color with small amount. These ashes presented yellowish green color not as much strong as Acacia ash, Poplar ash, Jujube tree ash. These are good for Irabo glaze.

• Journal of the Korean Ceramic Society
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• v.46 no.6
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• pp.548-553
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• 2009

This study is on the application of ceramic body and art glaze by using coal ash according to each wt%. Body color was turned red and dark as increasing coal ash contents in the body and art glaze because of the effect of noncombustible carbon in $Fe_2O_3$ and coal ash. Not only pore and black core were generated but also absorptance and shrinkage were increased as increasing coal ash contents. The glaze of coal ash 20 wt% showed blue absorption band, turned red band as increasing coal ash contents, $Al_2O_3\;to\;SiO_2$ ratio got lower and became mat because glaze is estranged from $Al_2O_3\;to\;SiO_2$ mol ratio 1:10 of transparent glaze as increasing coal ash contents. Glaze showed unstable dissolving condition in the more coal ash contents.

• Journal of the Korean Ceramic Society
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• v.52 no.3
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• pp.186-191
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• 2015

Tribological properties of whiteware with various transparent glazes, which have different composition and microstructure, were investigated. The wear resistance and friction behavior of the glazed whiteware are a very important aspect if the whiteware is used as tableware and for sanitation purposes. Generally, the wear property is influenced by the microstructure and surface morphology of the material. The whiteware specimens with two kinds of transparent glazes were fabricated by using the commercially available porcelain body. Furthermore, the commercial tableware, such as bone china, and traditional tableware were also examined as reference materials. All of the specimens showed that different pore structures might affect the mechanical and tribological properties. It seems that the wear resistance of whiteware is substantially related to the pore size and distribution of glaze rather than the hardness value of the specimen.

• Korean Journal of Materials Research
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• v.23 no.4
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• pp.233-239
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• 2013

We collected Seokganju minerals (regions in Gyeryong Mountain, Sangsin-ri, Banpo-myeon, Gongju Chungcheongnam-province), which were used as natural color pigments for grayish-blue during the 15th~16th centuries of the Joseon era, and investigated their crystallographic features to develop a black pigment having a spinel structure. By a Raman analysis, the color of Seokganju under transparent glaze as a pigment for painting was black because hematite ($Fe_2O_3$) in Seokganju was converted to magnetite ($Fe_3O_4$) However, Seokganju into the transparent glaze as a pigment was brown because of hematite ($Fe_2O_3$) and small amounts of maghemite (${\gamma}-Fe_2O_3$) in Seokganju minerals. Only Seokganju mineral is used, it is not suitable for black pigment into the transparent glaze. This study tried to develop a spinel crystal black pigment stabilized by Seokganju with CoO, $Cr_2O_3$, NiO, and $MnO_2$ at $1280^{\circ}C$. A Raman spectroscopy analysis was performed to verify the presence of Mn The results showed that it existed as spinel, and two crystal phases $CoFe_2O_4$ and $MnFe_2O_4$ were mixed. $CoFe_2O_4$ spinel has a dark grayish black color and $MnFe_2O_4$ spinel has a greenish black color, and these two appeared as black. The color of a specimen calcined by adding 6 wt% of pigment mixed with 5 wt% of $MnO_2$ added to lime glaze was analyzed with a UV spectrophotometer. When applying the color pigment, it appeared black stabilized with $L^*$24.23, $a^*$ 0.12, $b^*$ -2.29 at $1260^{\circ}C$ oxidative calcination, With $1240^{\circ}C$ reduction firing, it is appeared black stabilized with low brightness of $L^*$ 23.13, $a^*$ -1.12, $b^*$ 0.54.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.87-91
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• 2011

The purpose of this study is to develop ceramic glazes for the pottery production by utilizing wasted white porcelain, celadon porcelain and bone china thrown away from the areas of Icheon and Yeoju. Most of Korean pottery manufacturers are located in the both areas. According to the XRF analysis, the wasted white porcelain contains over 67 % of silica. It is enough to make a transparent glaze without adding silica. The wasted celadon porcelain contains much $Fe_2O_3$, which is suitable for producing a celadon glaze. The wasted bone china contains 22 % of $P_2O_5$, which is suitable for making a milky white bone china glaze. As a result, it is expected that production of pottery glaze using the wasted porcelains will reduce pollution problems comes from the landfill, and obtain economic effects in terms of resources recycling. It is also expected to be utilized as alternative materials of imported ones.

• Science of Emotion and Sensibility
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• v.19 no.2
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• pp.101-112
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• 2016

Selecting appropriate materials can be significantly important to make different image in the product and also give distinguished express to the users. A material for the ceramic product surface consists of the combination between a glaze and a body, and each attribution of materials and the way of the combination creates different texture and color. This study analyzes the difference between visually and tactually sensibility of ceramic surface to through the simulating both visual and tactual stimulation by verbal evaluation method. Totally 13 adjectives are selected from homepage of local and global ceramic product brand. And totally 12 ceramic samples are created with the consideration of color, glossiness and roughness. These 12 samples are the combination between four ceramic bodies (White porcelain, Celadon_c, Sancheong and Black soil) and three glazes (Transparent, Celadon_g, Black glaze). The respondents of first survey were asked to rub, touch and hold before evaluating the sensibility of ceramic surface and other respondents of second survey were asked to evaluate visual images of 9 samples which showed meaningfully difference from first survey. The surface which scored the highest sensibility with the first survey was 'pure' on a surface of White porcelain body with Transparent glaze, and the lowest was also 'pure' on a surface of Black soil body with Transparent glaze. The highest score in the second survey was the same result as the first survey, but the lowest scored 'casual' and the surface was Black soil body with Celadon glaze. By the comparison with two survey results, not every sensibility is same result shown as the first survey and the second survey, but the tactile sensibilities such as 'artistic', 'luxurious', 'sensuous', 'romantic' and 'mysterious' can be experienced by via visual materials of ceramic surfaces.

• Journal of the Korean Ceramic Society
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• v.51 no.3
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• pp.184-189
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• 2014

Electric arc furnace dust (EAFD) is a solid waste generated by the steel-scrap recycling process. It mainly consists of zinc oxides (ZnO), alumina ($Al_2O_3$), iron oxides ($Fe_2O_3$), and silica ($SiO_2$). Here we report the preparation and characterization of blue ceramic pigments using EAFD powder as a starting material. $(Zn(EAFD),Co)Al_2O_4$ blue ceramic pigment was prepared by the solid-state reaction method. The color characteristics of the pigment obtained were compared with those of pure $CoAl_2O_4$. The new pigment was characterized using XRD, CIE-$L^*a^*b^*$ color-measurements, SEM, and EDX. The XRD analysis revealed that the $(Zn(EAFD),Co)Al_2O_4$ pigment was composed of mainly the spinel phase of $(Zn,Co)Al_2O_4$. The $Zn(EAFD)_{0.25}Co_{0.75}Al_2O_4$ pigments showed a vivid blue color with a $b^*$ value of -28.64 and a good glaze stability with a transparent glaze.