• 보존과학회지
• /
• 제12권1호
• /
• pp.1-14
• /
• 2003

조선시대 관요가 위치한 경기도 광주의 백자에 대한 화학적인 특성을 살펴보기 위하여 백자요지에서 출토된 백자를 대상으로 X-선 회절 분석, 유도결합 플라즈마 원자방출 분광분석, 에너지분산 X-선 분광분석의 자연과학적인 방법을 이용하여 연구하였다. 백자요지에서 출토된 백자는 출토된 유구에 관계없이 유사한 태토로 제조되었으며, 태토의 제조에는 광물학적으로 같은 계통의 원료로 장석광물이 사용되지 않은 점이 특징적이다. 폐기물의 퇴적 1에서 출토된 백자는 백자요지의 다른 유구에서 출토된 백자와는 $Fe_2O_3$를 포함한 태토의 조성 및 광물학적인 특성에 차이가 있었다. 폐기물의 퇴적 떼서는 백자요지의 다른 유구와 성격을 달리하는 유물이 출토되었다는 발굴조사의 결과와 백자의 과학적인 분석결과와 일치하였다. 백자에는 유약성분의 특성상 라임계열과 알칼리-라임계열의 유약이 사용되었으며, 전반적으로 유약조성의 범위는 넓었다.

• Conservation and Restoration of Cultural Heritage
• /
• 제1권1호
• /
• pp.39-48
• /
• 2012

The first twenty-five years of scientific study within Korea on Korean traditional ceramics has been characterized as a bridging effort to understand the rich field of artistic ceramic masterpieces on one hand with analytic results gained from mounds of broken shards and kiln wastes on the other. First shard pieces were collected directly from the waste mounds, but most of the analyzed shards were provided by art historians and museum staffs directly involved in systematic excavations. The scientific study is viewed as one of many complimentary ways in learning about the multi-faceted ceramics culture, ultimately connecting human spirits and endeavors from the past to the present to the future. About 1350 pieces of analyzed shards have been so far collected and organized according to the production location and time period. From the experimental results of the analysis, the compositional and microstructural characteristics of bodies and glazes have been deduced for many kiln sites of Goryeo and Joseon dynasties. Except for a few local kilns, porcelain stone was used as body material in both dynasties. The principle of mixing a clay component with a flux material was used in Korean glazes as was in China. The clay component different from body clay was often used early on. In Gangjin a porcelain material appropriate for whiteware body was mixed for celadon glaze, and in Joseon Gwangju kilns glaze stone was chief clay material. The use of wood ash persisted in Korea even in making buncheong glazes, but in Joseon whitewares burnt lime and eventually crushed lime were used as flux material.

• 공업화학
• /
• 제24권4호
• /
• pp.382-390
• /
• 2013

소다석회 조성의 폐 병유리를 대상으로 효율적인 재활용방안을 찾기 위해서 발포화에 적절한 조성의 조절을 통해 직접 보온단열재 발포유리블럭을 제조할 수 있는 공정을 조사하였다. 폐 병유리의 직접 발포화를 위해 첨가되는 성분 및 조성은, 폐 유리분말 100중량부에 대하여 $SiO_2$ 10중량부, $Na_2SO_4$ 0.5중량부, $B_2O_3$ 3.0중량부, 그리고 발포제로서 카본 블랙류 탄소재 0.3중량부이다. 발포공정은 턴넬키른에서 진행하며, 발포소성 조건은 폐 유리분말의 입도는 -325 mesh, 발포소성온도는 $830{\sim}850^{\circ}C$, 발포시간은 30~35 min이 바람직하다. 상기 조건하에 제조된 발포체는 밀도가 $0.17{\sim}0.21g/cm^3$, 열전도도 $0.06{\pm}0.005kcal/h{\cdot}m{\cdot}^{\circ}C$, 수분 흡수율 1.1~1.5%, 압축강도는 $20{\sim}30kgf/mm^2$의 물성을 나타내었다.

• 한국세라믹학회지
• /
• 제53권2호
• /
• pp.215-221
• /
• 2016

In this study, the utilization of the by-products of various industries was examined using raw materials of CSA high-functional cement such as coal bottom ash, red mud, phosphate gypsum, etc. Technology to improve energy efficiency and reduce $CO_2$ was developed as part of the manufacturing process; this technology included lower temperature sintering ($150{\sim}200^{\circ}C$) than is used in the OPC cement manufacturing process, replacement of CSA cement with the main raw material bauxite, and a determination of the optimum mix condition. In order to develop CSA cement, a manufacturing system was established in the Danyang plant of the HANIL Cement Co. Ltd., in Korea. About 4,200 tons of low purity expansion agent CSA cement (about 16%) and about 850 tons of the lime-based expansion agent dead burned lime (about 8%) were produced at a rate of 60 tons per hour at the HANIL Cement rotary kiln. To improve the OPC cement properties, samples of 10%, 13%, and 16% of CSA cement were mixed with the OPC cement and the compressive strength and length variation rate of the green cement were examined. When green cement was mixed with each ratio of CSA cement and OPC cement, the compressive strength was improved by about 30% and the expansibility of the green cement was also improved. When green cement was mixed with 16% of CSA cement, the compressive strength was excellent compared with that of OPC cement. Therefore, this study indicates the possibility of a practical use of low-cost CSA cement employing industrial wastes only.

• 한국농공학회지
• /
• 제39권5호
• /
• pp.64-70
• /
• 1997

Sludge is generated in the process of water and wastewater treatment, and it has been causing various problems environmentally and economically. The firing technology in pottery industry was applied to the sludge treatment, and the final product was called artificial soil. For the production of artificial soil, lime and chabazite was used as additive, and the mixed material was thermally treated in the firing kiln at $300^{\circ}$ temperature for about 15 minutes. The physico-chemical characteristics of the artificial soil was analyzed and it showed that the artificial soil could be used as a soil conditioner for farmland. The concentrations of the toxic heavy metals in the artificial soil were lower than those in the soil quality standard for farmland. It was high in permeability, total nitrogen and total phosphorous concentrations and surface area of the artificial soil compared to the common field soil. Preliminary cost analysis showed that the sludge treatment cost for artificial soil was less than the disposal cost in the current landfill disposal method. This study illustrated that the artificial soil production process can be a feasible alternative for sludge treatment, and produced artificial soil may he applied to farmland without causing significant adverse effect. Further study is recommended for practical application of the system and verification of the longterm effect of the artificial soil on farmland.

• 펄프종이기술
• /
• 제46권2호
• /
• pp.1-7
• /
• 2014

Causticizing calcium carbonate (CCC) is produced as a by-product in the causticization step of the kraft pulping process. It is often calcined in a rotary lime kiln after being dewatered and reused in the causticizing process. But for the China mill, the conventional recycled way is difficult because the CCC is mainly obtained from non-wood pulping materials, which higher silicon content led to serious silicon obstacle. So it is often discarded as solid waste or used in landfill after dewatering and secondary pollution is brought. In order to prevent its secondary pollution, recent years, the CCC is used as a filler in China papermaking industry. In mill trials, the CCC can be used to replace an amount of precipitated calcium carbonate (PCC). Unfortunately, the application scope and dosage of CCC have been limited due to its lower sizing efficiency than PCC. In this study, the reason for the lower sizing efficiency of alkyl ketene dimer (AKD) when CCC was used as a filler was investigated. The results showed that the materials in green liquid, such as insoluble matter in green liquid, silicon and metal ions, were a little influence on the sizing efficiency of AKD. The higher BET and BJH pore volume of the CCC were the main reason for lower sizing efficiency of AKD when it was used as filler.

• 한국농공학회지
• /
• 제40권2호
• /
• pp.102-111
• /
• 1998

Large amount of sludge have been generating in the process of water and wastewater treatment in urban area, and it has been making many environmental problems. Currently almost of sludge is landfilled, and since sludge is difficult to handle and dehydrate, the permeated water from the filled-in ground contaminate the surrounding soil and groundwater which may cause serious environmental and sociological problems. The organic component in sludge can be almost removed through the heat treatment process, and the final product is called artificial soil or artificial media according to the temperature control. To produce artificial media using sludge, chabazite and lime were used as an additive, and the mixture of sludge & additives was thermally treated in the firing kiln at about 800~1, 100。C for about fifteen minutes. The physical and chemical characteristics of the produced artificial media were analyzed, and it showed that it can be used as an artificial media for plant production or soil conditioner for farmland. The concentrations of the toxic heavy metals in the artificial media were lower than the soil quality standard for farmland. The characteristics of produced artificial media, using the mixture of sludge and additives through the heat treatment, is similar to the natural chabazite and soil. The analyzed result of the mineral composition of artificial media showed that it has a characteristics similar to natural stable soil, so the produced artificial media may be applied to farmland or water culture without causing adverse effect. Therefore this study showed that the above process can be a feasible alternative for sludge treatment.

• 수도
• /
• 제24권5호통권86호
• /
• pp.29-44
• /
• 1997

Sewage sludge produced in Korea was 1,275,800 tons (dewatered sludge cake) per year in 1996, which is 3,495 tons per day, 0.303% of 11,526,100 tons per day of sewage treated in 79 sewage treatment plants. Sludge production has been and will be increasing in accordance with construction of new facilities for sewage treatment. Most of the sludge is currently disposed by landfill and ocean dumping, but it is becoming difficult to find suitable sites for landfill, particularly in big cities such as Seoul. In addition, rapid increase of landfill cost is anticipated in a near future. Current trend for sludge disposal in advanced countries is land application. Over the past 10 to 20 years in the United States, sludge management practices have changed significantly, moving from disposal to beneficial use. They use biosolid for utilization instead of sludge for disposal. Under the Clean Water Act of 1972, amended in 1987 by Congress, the U.S. EPA was required to develop regulations for the use and disposal of sewage sludge. The EPA assessed the potential for pollutants in sewage sludge to affect public health and the environment through a number of different routes of exposure. The Agency also assessed the potential risk to human health through contamination of drinking water sources or surface water when sludge is disposed on land. The Final Rules were signed by the EPA Administrator and were published (Federal Register, 1993). These rules state that sewage sludge shall not be applied to land if the concentration of any pollutant in the sludge exceeds the ceiling concentration. In addition, the cumulative loading rate for each pollutant shall not exceed the cumulative pollutant loading rate nor should the concentration of each pollutant in the sludge exceed the monthly average concentration for the pollutant. The annual pollutant loading rate generally applies to applications of sewage sludge on agricultural lands. The most popular beneficial use of sewage sludge is land application. The sludge has to be stabilized for appling to land. One of the stabilization process for sewage sludge is lime stabilization process. The stabilization process is consisted of the stabilizing process and the drying process. Stabilization reactor can be a drum type reactor in which a crossed mixer is equipped. The additive agents are a very reactive mixture of calcium oxide and others. The stabilized sludge is dried in sun drier or rotary kiln.

• 한국세라믹학회지
• /
• 제26권2호
• /
• pp.187-194
• /
• 1989

Synthesis of spinel pigment on ZnO-Fe2O3 system. The object of this research is the synthesis of new spinel pigments on the basic of ZnO-Fe2O3 system which was substituted by ZnO-Fe2O3 by MgO-Al2O3. This research was progressed by measuring the X-ray diffraction and the reflectances of the substitued ZnO-Fe2O3 group. Which was obtained by sintering at the temperature of 1,00$0^{\circ}C$, 1,10$0^{\circ}C$, 1,20$0^{\circ}C$ and 1,25$0^{\circ}C$ and them by regrinding. In order to coloring test, here basic compositions of Barium glaze, Zinc glaze, Lime glaze, Lead glaze and Talc glaze used in this experiment are obtained from the ceramic work. Adding synthetic stains in these basic glazes with 3%, mixing and glazing on the specimen. The specimens was fired at 1,28$0^{\circ}C$ in reducing and oxidizing atmosphere in the gas kiln. The results of the research as follow. 1. Many kinds of spinel pigment was produced on ZnO-Fe2O3 system that is to say, not always only spinel. 2. Spinel peak was observed strongly on the ZnO-Fe2O3 system withsubstituting by MgO-Fe2O3 and MgO-Al2O3 group(the ratio of MgO, Al2O3 being increased, observed more strongly). 3. The most effective temperature ranges was 1,20$0^{\circ}C$~1,25$0^{\circ}C$. 4. The color of spinel pigments on this system was observed by "stable YR". 5. It was yellow red in oxidizing and green in reducing atmosphere on the coloring test.ring test.

• Journal of the Korean Wood Science and Technology
• /
• 제2권2호
• /
• pp.8-12
• /
• 1974

한국의 목재 인공 건조법을 개발하기 위하여 필자의 전직 대학인 전북대학교 전 김두헌 총장님, 동농대전 백남혁학장 및 동농대교수 제위의 각별한 협조를 얻어 1956년 고액을 지불하고 미국 More Dry Kiln Co.에서 최신의 목재 인공 건조 장치를 도입하여 전북 농대 임학과에 설치하게된 것이다. 그러나 이 건조 시설을 활용하는데는 많은 지장이 있었으므로 1959년 전기 More Dry Kiln의 온, 습도 조절장치만을 이용한 소형 Dry kiln을 제작하여 본 시험을 실시한 것이다. 공시수종은 소나무, 낙엽송, 은행나무, 전나무, 밤나무 및 감나무등이며, 공시목의 크기는 것이 60cm, 넓이 10cm 및 두께 15-35mm이다. 실험한 건조 조건은 건조 온도를 일정히 ($170^{\circ}F$)하고, 관계습도를 각종으로 변화할때 얻어지는 건조 속도를 측정하는 동시에 각 건조조건에 의하여 유발되는 건조결함을 조사하여 공시목의 초기 함수율과 건조 최경함수율 특히 shell의 함수율과의 비가 이들의 결함 형성 특히 표면경화(casehardening) 형성에 미치는 영향을 구명하였으며 또한 casehardening 계산식을 유도하였다. 1. 목재내부에 형성된 응력 즉 prong이 개주할 때의 응력은 prong이 서로 접합할 때의 응력을 100으로 하는 백분율에 의하여 다음식으로 표시할 수 있다. 단, 응력 측정에 사용한 prong은 그림 1과 같이 작성하여야 한다. $CH=\frac{(A-B') (4W+A) (4W-A)}{2A[(2W+(A-B')][2W-(A-B')]}{\times}100%$ 상식은 다음과 같은 간이식을 사용할 수 있다. $CH=\frac{A-B'}{A}{\times}200%$ 2. 일정 한 건조 조건하에 건조하여 항중에 달하고, 또한 normal casehardening을 형성하는 경우에 는, 그 sample board의 shell 의 함수율은 특히 얇은 sample board에 있어서 US Dep. Agr., Forest Products Laboratory에서 발표한 EMC 보다 낮다. 3. 본 실험에서 측정한 1시간당 목재 건조 표면적 $1cm^2$ 당 증발하는 증발량 즉 건조속도를 비교 검토한 결과 다음과 같은 순위로 되었으며, 비교 검토한 5수 종중 최대치를 유하는 은행나무 MC 20% 에 있어서 최저치를 표시한 밤나무의 3.8배가 된다. (표 1 참조) (1) 은행나무 (2) 감나무 (3) 소나무 (4) 낙엽송 (5) 밤나무 특히 함수율 26% 이하에 있어서 각 함수율에 대한 증발속도치는 다음과 같은 일차식으로 표시 할 수 있으며, 그 회귀계수 유의성 검정에 있어서의 T치는 다음과 같이 각각 고율의 유의성을 표시하였다. (표2 참조) 상기중 Y는 증발속도($g/cm^2hr$.), X는 함수율을 각각표시한다. 이들 회귀직선을 도시하면 그림 2와 같다. 4. 초기함수율과 건조 최종기에 있어서의 목재의 표층 함수율 즉 shell의 함수율과의 비(SR)가 casehar dening 형성에 미치는 영향은 다음과 같다. 어떤 SR 값에 관하여 그 SR 값 이하를 유하는 총개제수(N) 중 CH 제4급이 출현하는 수(D)의 확율 즉 N에 대한 D의 출현확율 P%는 표 3과 같다. (D의 출현확율 P%를 위험확율이라고 가칭한다.) 표 4에 있어서 종란의 1,2,3의 숫자는 각각 다음과 같은 사항을 표시한다. (1) CH 값 제 4급이 출현하지 아니 하는 안전한 최소 SF 값 (2) 위험을 30%를 허용하는 경우에 있어서의 SF 값의 한계 (3) CH 값 제 4급 이하가 발생하지 아니하는 위험율 100%의 값의 범위 상기한 실측 결과에 의하여 밤나무, 낙엽송등은 내부응력 형성이 용이한데 비하여 감나무, 소나무등은 내부응력 형성이 용이하지 아니하여, 특히 전나무, 은행나무등은 타수종과 동일한 건조조건에 있어서 reverse casehardening을 초래함에 비추워 타수종에 비하여 현저히 내부응력 특히 normal casehardening이 잘 형성되지 아니한다는 것을 알 수 있다. 5. casehardening을 제외한 각종의 drying defects는 long time loading에 있어서 그 내부응력이 ultimate stress를 초과할 때 나타나는 것인데 건조조건 온도 $170^{\circ}F$에 대하여 습도를 낮게하여도 그렇게 심하지 아니하나, 온도 $200^{\circ}CF$의 저습에 있어서 end coating을 하지 아니하는 경우에는 용이하게 발생한다. 특히 밤나무는 실험한 타수종에 비하여 casehardening 및 활열성 defects가 강한 것을 지적할 수 있다.