• Journal of Conservation Science
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• v.33 no.6
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• pp.497-506
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• 2017

An investigation on the records of old document was conducted to identify the producing area of white clay and there were on-the-spot surveys to secure raw materials of white clay pigment. Based on the survey results, six raw materials were obtained from the region of Gangwon-do and Gyeongsang-do, South Korea and white clay pigment was subsequently manufactured by applying the hydraulic elutriation method. The results show that the major constituent minerals of YBW, HBW, and MCW were quartz and plagioclase, whereas SGW, HOW, and HGW were composed of clay minerals such as kaolinite and illite. HGW showed the highest $L^*$-value of 92.9. HOW and HGW showed an opacity of 94.1% and 89.6%, respectively, and they had excellent spreadability (270.3 mm and 223.3 mm, respectively). Therefore, HGW, HOW, and SGW have excellent characteristics in terms of color, opacity, and spreadability, and are considered to be highly applicable as white pigments for the Dancheong.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.197-202
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• 2021

In this study, activated clay treated with H₂SO₄ (20% by weight) and heat at 90 ℃ for 8 h for acid white soil was used as an adsorbent for the removal of PO₄^3--P in water. Prior to the adsorption experiment, the characteristics of activated clay was examined by X-ray Fluorescence Spectrometry (XRF) and BET surface area analyser. The adsorption of PO₄^3--P on activated clay was steeply increased within 0.25 h and reached equilibrium at 4 h. At 5 mg/L of low PO₄^3--P concentration, roughly 98% of adsorption efficiency was accomplished by activated clay. The adsorption data of PO₄^3--P were introduced to the adsorption isotherm and kinetic models. It was seen that both Freundlich and Langmuir isotherms were applied well to describe the adsorption behavior of PO₄^3--P on activated clay. For adsorption PO₄^3--P on activated clay, the Freundlich and Langmuir isotherm coefficients, K_F and Q, were found to be 8.3 and 20.0 mg/g, respectively. The pseudo-second-order kinetics model was more suitable for adsorption of PO₄^3--P in water/activated clay system owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal than the pseudo-first-order kinetics model. The results of study indicate that activated clay could be used as an efficient adsorbent for the removal of PO₄³-P from water.

• Journal of Conservation Science
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• v.36 no.3
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• pp.152-161
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• 2020

The purpose of this study was to compare the chemical properties of white soil and refined clay sediment, which are produced early in the refining process. The characteristics of the white wares made at the kiln site in Goseong-ri, Chuncheon were also examined. Three groups of materials were examined: white wares excavated from the white wares kiln, raw material from white soil collected from the surface, and a refined clay sediment group. There were also three analysis methods, which were a main components analysis, a trace components analysis, and a mineral analysis. The main components analysis found that the white wares clay was in the RO₂4.04~4.28 and the RO + R₂O 0.30~0.31 mole areas, which were similar to the results for the refined clay sediment. However, the refining process used to produce better quality white wares meant that the large differences in the early white soil raw material appeared in the refined sediment. The mineral phase analysis showed that the crystals detected in the early white soil raw materials and refined clay sediment were almost identical. However, quartz and mullite mineral phases, which can occur above a certain temperature, were detected in the excavated white wares clay. Rare earth elements that were not affected by the pottery making process and the weathering of clay materials were found to have the same origin in all three groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.57-62
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• 2018

This study was designed to analyze the chemical composition and antioxidant activity of various vegetable oils (pumpkin seed oil, camellia seed oil, red pepper seed oil and peanut oil) using adsorbents (active carbon, acid clay, kaolin). Their chemical composition was analyzed by GCMS. Their antioxidant activity was evaluated by measuring their DPPH and ABTS radical scavenging activity. After the treatment with the adsorbents, the contents of most of the fatty acids and active ingredients contained in the four kinds of vegetable oils were reduced. After the treatment with the three adsorbents, the linoleic acid and erythrodiol contents of the pumpkin seed oil were reduced. In the case of the camellia seed oil, the fatty acids content was decreased, but there was no loss of vitamin E after the acid clay treatment. The content of the compound capsaicin, which forms part of the spicy component of red pepper seed oil, was reduced by 53.33% after the acid clay treatment. The peanut oil showed the lowest loss of sitosterol compound in the group treated with active carbon. The antioxidant activity was observed to be in the order of pumpkin seed oil (kaolin>acid clay>active carbon), camellia seed oil (acid clay>kaolin>active carbon), red pepper seed oil (kaolin>acid clay>active carbon) and peanut oil (active carbon>acid clay>kaolin).

• Korean Journal of Food Science and Technology
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• v.12 no.2
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• pp.126-132
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• 1980

An attempt was made to remove red color and capsaicin which were contaminated in crude oil extracted from red pepper seeds with n-hexane. Both clay bleachidg and deodorization were responsible for the removal of red color. Clay bleaching was also the most effective for the removal of capsaicin, which was removed completely with 4 % clay. Capsaicin in oil was adsorbed onto the clay particles exponentially and it followed Freundlich equation : ${\frac{x}{m}}=1.1\;c^{0.31}$, where x is amount of capsaicin adsorbed (mg/ml), m is amount of clay used in bleaching (%) and c is amount of residual capsaicin (mg/ml). Neutral lipid of the seed oil consisted of 95.8 % triglyceride, 1.55 % sterol ester, 1.45 % monoglyceride, 0.78 % free fatty acids, 0.2 % diglycerides and 0.15 % sterol. Major components of fatty acids in the red pepper seed oil were linoleic acid (78.79 %), palmitic acid (15.27 %) and linolenic acid content was only 0.63 % by high performance liquid chromatography.

• Journal of Pharmaceutical Investigation
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• v.2 no.1
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• pp.31-39
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• 1972

국산산성백토(國産酸性白土)를 정제(錠劑)의 붕노제(崩努劑)로 개발(開發)하고자 종내(從來) 붕해제(崩解劑)로 사용(使用)해 오든 corn starch, calcium methylcellulose, kaolin, calcium silicate 및 Pectin과 국산산성백토(國産酸性白土)를 붕해제(崩解劑)로하고 정제(錠劑)의 주약성분(主藥成分)으로서는 불용성(不溶性)인 Ca-PAS KP II 를 택(澤)하였다. 이상(以上)의 각(各) 붕해제(崩解劑)의 一錠當(일정당) 함양(含量)을 0%에서 25%까지 7종(種)으로 달리하고 이것을 각각(各各) 사용(使用)하여 만든 과립(顆粒)의 입자도(粒子度)도 각각(各各) 4종류(四種類)로 분류(分類)하였다. 여기에 활택제(滑澤劑) 로서 0.5% mg-stearate를 공통(共通)으로 첨가(添加)하였다. 이상(以上)을 각각(各各) 동일(同一)한 조건하(條件下)에서 타정(打錠)하여 수종(數種)의 정제(錠劑)를 만들었다. 이들 정제(錠劑)에 대(對)하여 경도(硬度)및 붕해도시험(崩解度試驗)을 하여 비교검토(比較檢討)한 결과(結果) 다음과 같은 결론(結論)을 얻었다. 1. Corn starch는 우수(優秀)한 붕해제(崩解劑)이나 그첨가량(添加量)이 8%이상(以上)이 될 때 는 타정시(打錠時) 압력(壓力)을 받지 않어 정제(錠劑) 붕해제(崩解劑)로서 사용(使用)할 수 없었다. 2. Ca-Mc는 붕해제(崩解劑)로서 첨가량(添加量)이 8%이상(以上) 일때에도 사용가능(使用可能) 하였으나 15%이상(以上) 일때는 타정시(打錠時) 압력(壓力)이 약(弱)해졌다. 3. Kaolin 붕해제(崩解劑)로서 부적당(不適當) 하다고 사려(思慮)되였다. 4. Ca-silicate도 붕해제(崩解劑)로서 적당(適當)하였으나 Pectin은 가장 부적당(不適當)하였다. 5. 산성백토(酸性白土)는 정제붕해제(錠劑崩解劑)로서 타정시(打錠時) 25% 첨가시(添加時)에도 압력(壓力)을 잘 받어 정제(錠劑)의 경도(硬度)를 유지(維持)할수 있었을 뿐만 아니라 붕해도(崩解度)도 양호(良好)한 성적(成績)을 나타내여 가장 우수(優秀)한 붕해제(崩解劑)임을 확인(確認)하였다. 6. 일반적(一般的)으로 타정(打錠)에 사용(使用)되는 과립(顆粒)의 size가 적을수륵 붕해시간(崩解時間)은 짧았으며 정제(錠劑)의 경도(硬度)가 높을수록 붕해시간(崩解時間)은 길었다. 그러나 정확(正確)한 비예성(比例性)은 찾기힘들었다.

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.663-668
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• 2002

Cation exchange capacity of clay, white clay and zeolite was estimated by performing the powder adsorption test for 6 different heavy metal (Cd, Cr, Cu, Fe, Pb and Zn) standard solutions whose concentrations were varied by 5,10,15 and 20 ppm. The adsorption rate of heavy metals decreased with increasing the concentration of standard heavy metal solutions. The adsorption rate of the clay and the white clay showed more than 80% for the all tested heavy metals except Cr and especially above 99% for the Fe and the Pb. The Cr adsorption rate of the mixture of the clay and the white clay increased, however, that of Zn decreased. The adsorption rate of Cr and Zn showed relatively lower values as compared with those of the other heavy metals because the cation exchange H$\^$+/ ions and heavy metal ions of the clay or the white clay were in competition at low pH region.

• KSBB Journal
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• v.15 no.4
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• pp.342-345
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• 2000

A novel pre-purification method was developed for producing peroxidase to guarantee high purity and yield from plant cell cultures in large-scale process. This method was a simple and efficient procedure for the isolation and pre-purification of peroxidase from the biomass consisting of active clay treatment followed by cationic exchange chromatography. The use of active clay in the pre-purification process allows for rapid and efficient separation of peroxidase from interfering compounds and dramatically increases yield and purity of crude peroxidase for purification steps compared to alternative processes. This pre-purification process serves to minimize the buffer usage size and complexity of the HPLC operations for peroxidase purification. This process is readily scalable to a pilot plant and eventually to a production environment where mass production of material are expected to be produced.

• Journal of the Korean Ceramic Society
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• v.39 no.8
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• pp.728-734
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• 2002

Stabilization behavior of Cr, Cd, Cu, Pb, Fe and Zn heavy metals in the EAF dust was investigated by adding EAF dust to clay or white clay, respectively, up to 50 wt% with 10 wt% intervals and sintering at temperatures between 200 and $1200^{\circ}C$ with $200^{\circ}C$ intervals with an aid of ICP-AES followed by TCLP test to evaluate heavy metal cation exchange capacity of the clay or the white clay. The clay or the white clay had a better Cr ion exchange capacity than that of zeolite. The TCLP leaching test for the sintered specimens showed that Cr and Fe were rarely detected for all the specimens and the concentration of Cd and Zn decreased with increasing sintering temperature and decreasing EAF dust contents respectively. When the clay or the white clay were mixed with EAF dust, cation exchange may occur between the clay and the EAF dust so that the first stabilization of the mixtures containing semistabilized heavy metals may happen. Stabilization of heavy metals in the ceramic bodies was further completed probably due to the eutectic reaction caused by the sintering of semi-stabilized mixtures. It was conceivable that the white clay rather than the clay may be a better stabilizer for the EAF dust containing heavy metals.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.560-567
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• 2016

Acid-activated clays (SUPER-DC, DC-A3, and P1) are used for the bleaching of cold-pressed rapeseed oil. In this study we tested the bleaching performance of cold-pressed rapeseed oil according to the different reaction time (20, 40, 60, 80 min) and temperature (40, 80, $120^{\circ}C$). Oil color (lightness, redness, yellowness), pigments (chlorophyll A and carotenoid content) and quality properties (fatty acid composition, tocopherols (${\alpha}$, ${\beta}$, ${\gamma}$, ${\delta}$), and plant sterols (${\beta}$-sitosterol, campesterol, stigmasterol) content) were analyzed. The results showed that bleaching of cold-pressed rapeseed oil with 2% acid-activated clays at $40^{\circ}C$ for 20 min, brightness (L) increased, but redness (a) and yellowness (b) decreased. Bleaching of cold-pressed rapeseed oil with 2% DC-SUPER at $40^{\circ}C$ removed chlorophyll A and carotenoids pigments significantly. In addition, about 50% of total tocopherol content in cold-pressed rapeseed oil was reduced by bleaching. Originally total tocopherol content was 46.62mg/100g in cold-pressed rapeseed oil. But after bleaching, total tocopherol content was 12.67mg/100g (20 min bleaching), 15.31mg/100g (40 min bleaching), and 13.56mg/100g (60 min bleaching). However plant sterols content in cold-pressed rapeseed oil remained unchanged by bleaching. Overall, acid-activated clays were useful for the bleaching of pigmented rapeseed oil.