본 연구는 객토를 한 간척지에서 석고시용 수준이 알팔파의 수량과 사료성분에 미치는 영향을 알아보고자 수행하였다. 실험장소는 간척한지 17~33년 경과된 석문간척지로서 약 70 cm 정도 객토한 토양이었다. 객토에 사용한 흙은 섬토양의 제염을 하지 않은 것 이었다. 처리는 석고를 시용하지 않은 0 ton/ha 구(G0), 석 고를 2 ton/ha(G2) 및 4 ton/ha(G4) 시용한 구로 하였다. 수확은 알팔파가 개화초기(개화 10%)에 도달할 때 1차 수확하였으며 이 후 수확은 약 35일 간격으로 수확을 하였다. 알팔파의 건물수량은 1차 년도는 G2가 G0와 G4보다 유의적으로 높았으며 2차 년도는 처리간 유의적인 차이는 없었으나 G2가 G0와 G4보다 높은 경향을 보였다. G2에서 알팔파의 건물수량이 높은 이유는 토양의 pH 및 EC가 각각 재배가능 및 재배적합 수준이었고 피복도 및 알팔파 식생비율도 높은 것에 기인하였다. 1차 및 2차 년도 모두 석고 처리 간 CP, NDF 및 ADF 함량 및 RFV는 차이가 없었다. 한편 1차 및 2차 년도의 연구결과를 통해서 알팔파 건물수량에 부정적인 영향을 주는 요인은 봄의 가뭄과 여름의 집중된 강수로 나타났다. 이상으로부터 객토 간척지에서 석고 처리는 알팔파의 건물수량을 높이는데 효과적인 것으로 판단되며 2 ton/ha이 적정 수준인 것으로 사료된다.

Active clay, bentonite and zeolite were used as porous materials for humidity controlling ceramic boards. The specific area and the pore volume of active clay were higher than bentonite and zeolite. The flexible strength of the gypsum board decreased with an increasing amount of porous material, and the flexible strength was lowest when active clay with a higher specific surface area than others porous materials was added. The specific surface area and total pore volume of ceramic boards containing porous material were highest at 102.25 m2/g, 0.142 cm3/g, respectively, when the active clay was added. In addition, as the amount of added porous materials increased, the specific surface area and total pore volume of the ceramic board increased, but the average pore diameter decreased. The addition of s porous materials with a high specific area and a large pore volume improved the moisture absorptive and desorptive performance of the ceramic board. Therefore, in this experiment, the moisture absorptive and desorptive properties were the best when active clay was added. Furthermore, as the amount of added porous materials increased, the moisture absorptive and desorptive properties improved. When 70 mass% of active clay was added to α-type gypsum, the hygroscopicity was the highest, about 300 g/m2, in this experiment.

With increasing public awareness regarding radon, this study has been conducted with the aim of providing more accurate information about radon to the public. We investigated the radon emissions from gypsum boards, which are known to emit relatively higher levels of radon among the building materials available on the market. Radon emissions were measured over three weeks using the closed chamber method with nuclear track detectors. For ceiling materials, the arithmetic mean of the radon emissions was 43.8 ± 42.2 Bq/m3 (geometric mean: 28.9 ± 5.6), 156.2 ± 150.5 mBq/m2/h per unit area (geometric mean, 103.1 ± 2.7) and 21.1 ± 19.9 mBq/kg/h per unit mass (geometric mean: 14.4 ± 2.6). Regarding the wall materials, the arithmetic mean of radon emissions was 24.1 ± 24.0 Bq/m3 (geometric mean: 15.6 ± 2.6), 133.3 ± 143.4 mBq/m2/h per unit area (geometric mean, 76.8 ± 3.0) and 13.0 ± 10.4 mBq/kg/h per unit mass (geometric mean, 9.5 ± 2.3). According to the results of this study, higher radon concentrations and emissions were detected in the ceiling materials than in the wall materials, but these values were lower than those previously measured in building materials.

In this article, poly methyl triethoxy silane was compounded with an inorganic waterproof admixture at a certain ratio to improve the performance of gypsum products; a new type of high-efficiency compound water-proofing additive was also investigated. Furthermore, the waterproof mechanism and the various properties on the hardened gypsum plaster were investigated in detail by XRD and SEM. The results show that the intenerate coefficient of gypsum plaster increased to more than 0.9; the water absorbing rate decreased to less than 10 %. Both the bending strength and the compressive strength of gypsum plaster increased by various degrees. The intenerate coefficient reached a maximum value of 0.73 and the strength of the samples showed almost no change when 5 % cement alone was added. In this new type of the high-efficiency compound with waterproof additive, the optimal technological parameters for formulas were obtained to be: 5 % cement, 18 % mineral powder, and 0.8 % poly methyl triethoxy silane, to compound gypsum plaster. Meanwhile, the production of high performance gypsum as a building material has become possible.

Developing proper reduction strategies of indoor radon which have been an important issue in Korea requires proper information on source characteristics a phosphate gypsum board which is a common building material used for inter-wall thermal protection in Korea could be a major source of indoor radon level. This study evaluated the correlation between indoor radon concentration and the attribution of gypsum board content in building materials. In this study we valuated indoor/outdoor radon from 58 facilities selected based on the information availability of gypsum content in the building material across 8 different cities in Korea. Our results showed that indoor radon concentrations were 2 to 3 times higher than outdoor but those results were not significantly attributed from gypsum contents in the building material. Indeed, phosphate content in gypsum board did not significantly play a role in indoor radon level variations. It is concluded that physical environmental condition such as temperature, relative humidity, radon exhalation rate out of each building materials, as well as pathway from external sources (e.g., soil) needs to be identified to develop indoor radon reduction strategies.

Active clays, Diatomite, bentonite and zeolite were used as porous materials for fabricating hygroscopic gypsum boards. Pohang active clay and Cheolwon diatomite showed excellent characteristics of moisture adsorption and desorption. These characteristics were caused by higher surface area and pore volume of porous materials. Moisture adsorption content of gypsum board with 10% active clay(P1) was 62.0 g/m2, and moisture desorption content was 50.2 g/m2. Moisture adsorption content of gypsum board with 10% diatomite(P) was 59.5 g/m2, and moisture desorption content was 49.0 g/m2. Moisture adsorption contents of gypsum boards with porous materials were higher than that moisture desorption contents of gypsum board without porous materials. Correlation coefficient between surface area and moisture adsorption content of gypsum boards was 0.98. Also, correlation coefficient between surface area and moisture desorption content of gypsum boards was 0.97. Moisture adsorption and desorption contents were influenced by surface area and pore volume of the gypsum boards, and surface area had a larger effect on moisture adsorption and desorption.

Recently, functional building materials have been developed and introduced to the market. Many building materials emit volatile organic compounds(VOCs) which have the potential to affect health and comfort, and moisture problem has a major role also being established in indoor air quality (1AQ) problems. The purpose of this study is to evaluate the performance of reduction of HCHO using the gupsum board and water vapour adsorption/desorption property for ceiling board for mock-up test room and test house. The mock-up test is conducted according environmental standard method for indoor air quality of the ministry of environment. The results of this study are as follows, the reduction of HCHO gypsum boards are showed an effect to reduce the formaldehyde(HCHO) concentration of mock-up test room and test house. The indoor humidity is also showed to be lower than the general ceiling materials, since there is increased in the absorbed indoor humidity by using a humidifier with moisture adsorption/desorption ceiling materials. In natural conditions, moisture adsorption/desorption ceiling materials is showed a higher humidity than general ceiling materials constructed in the mock-up test room. However It changes of moisture adsorption/desorption is not appeared in test house. Therefore, in case of decreasing and increasing in humidity, these materials can be offset by reduction of HCHO using the gypsum board.

Changes in dry matter yield, crude components, nutrients uptake(P2O5, K2O, CaO, MgO) and sulphur containing amino acid(cysteine, methionine) of orchardgrass(Dacty1is glomerata. L) and alfalfa(A4edicago sativa. L) by gypsum application(as sulphur so

The effect of gypsum application was tested on dry matter yield, sulfur uptaken, composition of Ritrogen compound and sulhr compound and sulfur balance in mixed pasture. Total dry matter yields and sulfur uptake by grasses increased with the increasing of

The purpose of this study is to compare the compression strength of gypsum substituted mortar with that of mortar. After replacing the cement with the loess, a portion of the remaining cement was replaced with gypsum to make specimens. When the gypsum is replaced, the strength of all the specimens is lower than that of the standard specimen. It is necessary to use a long-term strength mixed material to replace this.

우리나라의 경우 1990년대부터 환경오염문제의 사회화가 배경이 되어 환경에 대한 관심이 높아짐에 따라 1998년부터 배기가스의 탈황공정이 가동되어 화학석고가 발생하기 시작하였는데 이것이 화력발전소에서 부산물로 나오는 배연탈황석고이다. 국내의 석탄화력 발전소에 설치된 탈황설비는 흡착재로 석회석 분말을 사용하고 부산물로 석고를 생성하는 습식공정으로서, 배연탈황석고는 이수석고(CaSO4⋅2H2O)로 생성되는데, 인산석고와 비교할 때 pH가 중성이며 높은 순도의 균일한 품질을 가지고 있어 발생 전량이 시멘트 및 석고보드 원료로서 재활용되고 있다. 한편 최근 그 수요가 증가하는 고강도콘크리트 혼화재, 슬래그 시멘트에 사용하기 위하여 년간 30만톤 이상 수입되고 있는 천연무수석고는 우리나라에 광물로 부존하지 않는다. 선진국과 마찬가지로 배연탈황 석고가 전량 수입되고 있는 천연석고를 대체할 수 있다는 장점에 대하여 충분히 인식함에도 불구하고, 아직까지 전반적인 기술 기반의 취약성 및 인력 부족으로 석고보드 제조 등 초보적인 수준에 머물러 있으나 최근 콘크리트 혼화재료 제조기업은 중국의 값싼 제품으로 인해 가격 경쟁력을 상실하고 있어 미래 경쟁력 있는 분야로의 전환을 위해 배연탈황 석고를 이용한 고부가성 건설재료 제조 기술에 관심을 가지기 시작하고 있다. 이에 본 연구에서는 지속가능 친환경-고성능 건설용 복합재료의 생산 및 이의 활용 기술을 적극적으로 개발하고자 인공신경망 모델을 활용한 배연탈황석고 모르타르의 배합조건과 물리적 결과값의 데이터를 다양한 알고리즘에 적용하여 이의 분석과 예측의 정확성을 판별하여 기초데이터로 제공하고자 한다.

In South Korea, the “Waste Control Act” regulates the use and purpose of recycling waste and specifies recycling methods and specific standards. However, these processes requires a long time and large budget, because they need to be reviewed based on data specific to the type of waste involved. The use and purpose of recycling can be considered by its functional and environmental aspects. The functional aspect of recycling may vary widely, depending on product characteristics In contrast, environmental standards will have more points in common. Recycling standards that consider the environmental impact and characteristics of waste are not prepared specifically. Therefore, when a large amount of waste is recycled, or recycling standards are applied to a new type of waste, the methodology for review of its environmental characteristics can be controversial. This study is meant to recognize the necessity of recycling standards and to prepare environmental standards and new recycling purposes for waste related to recycling three types of gypsum waste (phospho, titan, desulfurization). Several companies were selected for this study. In the gypsum waste-generating company, gypsum waste samples were collected and analyzed for pH, heavy metal content, water content, hazardous substance content, etc. In addition, we attempted to obtain the company's opinions on waste recycling. We determined the hazardous materials found in these three types of gypsum waste, raised awareness of waste, and confirmed that industry waste can be efficiently recycled for new uses under the improved.

우리나라의 모든 석탄화력 발전소 탈황공정은 흡수재로 석회석 분말을 사용하는 습식 처리공정으로서 공정의 부산물로 FGD(배연탈황)석고가 발생하는데 석회석 분말 1kg 주입 시 약 1.5kg에서 1.7kg의 배연탈황석고가 이수석고(Calcium Sulfate Dihydrate, CaSO4･2H2O)형태로 발생한다고 알려져 있다. 배연탈황석고는 황산칼슘의 농도는 높고 불순물은 적은 편으로 품질면에서는 천연석고에 비해 크게 뒤지지 않지만 결정구조가 대부분 둥근 침상구조를 형성하고 부분적으로 판상의 결정을 나타내고 있어 천연석고처럼 수화반응에 의해 자경성(self-setting)을 가지지 못하므로 대부분 시멘트의 원료로 사용되고 그 중 일부는 석고보드에 제한적으로 활용되고 있는 실정이다. 따라서, 배연탈황석고 그 자체로만은 현재 고부가가치가 있는 원료로서는 활용되기 어려운 실정이고 대부분 천연무수석고가 사용되고 있으며 이는 고가의 수입에 전량 의존하고 있다. 이에 따른 배연탈황석고의 향후 발생량은 200만 톤을 상회할 것으로 추정할 경우 기존의 단순 재활용에서 이의 부가가치가 높은 건설재료로의 활용이 요구되고 있다. 이에 본 연구에서는 기존의 천연석고와 시멘트를 대신하여 배연탈황석고 및 고로슬래그 미분말 등의 산업부산물을 주원료로 고강도 콘크리트 혼합재로 활용하고자, 배연탈황석고의 원시료 분석 및 배연탈황석고, 고로슬래그미분말의 혼입률에 따른 유동성, 증기양생 조건에서의 강도발현 특성 등의 물성평가를 진행하였다. 연구결과 배연탈황석고를 혼합재로 활용 시, 그 혼입률에 따라 모르타르의 유동성이 다소 감소하는 경향을 나타내었으나, 증기양생 시 초기 압축강도발현성이 우수하였으며, PHC-Pile, 박스암거 등 콘크리트 2차 제품으로 활용시 환경적･경제적으로도 그 효과가 매우 기대된다.

산업혁명 이후 산업발달과 더불어 폐기물 발생량 또한 크게 증가하였다. 이에 따라 정부에서는 폐기물 발생량을 감소시키는 것과 동시에 폐기물을 효율적으로 처리하고 이용하는 자원순환형 폐기물 관리체계로 전환하기 위해 법적, 제도적 체계를 구축하고 있다. 이러한 체계에 따라 생활폐기물, 건설폐기물, 사업장폐기물이 재활용 되고 있다. 사업장 폐기물 중 폐석고는 건축 공업용 페인트, 인쇄 잉크, 도자기 등을 생산하는 과정에서 발생되는 사업장 폐기물로서 연간 약 400 만톤이 발생되고 있다. 발생된 폐석고는 석고보드 및 농업용으로 재활용 되고 있다. 하지만 재활용되지 못한 잉여분은 매립시설에 매립되고 있는 실정이다. 따라서 다른 추가적인 재활용 방안이 필요하다. 일반적으로 MICP(microbially induced calcite precipitation)는 urea 가수분해 효소를 생성하는 미생물의 urea 분해 메커니즘을 통해 탄산칼슘과 같은 탄산염을 석출시키는 기작을 말한다. 최근 국내･외로 MICP 기작에 대한 연구가 진행되고 있으나 폐석고를 재활용함에 있어 MICP 기작을 이용한 연구는 미흡한 실정이다. 본 연구에서는 매립시설에 매립되는 폐석고의 물리･화학적 전처리를 통해 최적의 칼슘이온 용출 조건을 도출하고, MICP 기작을 통한 탄산칼슘 형성을 확인하여 폐석고를 재활용함에 있어서 MICP 기작을 활용하는 기초자료를 제시하는데 목적을 두었다. 이를 위해 폐석고의 특성을 파악하고자 XRD, XRF, 입도분석을 실시하였으며, 물리･화학적 전처리에 따른 칼슘이온 농도를 ICP-AES로 분석하였다. 특히, 미생물 투입 후 형성된 침전물에 대하여 XRD 및 FE-SEM 이용하여 시료를 분석하였다.

In this study, the recycling water that produced during remicon manufacturing was activated by desulfurization gypsum, and then mortar with activated-sludge was made. As a result, possibility of activated-sludge in remicon was verified via flow and compressive strength test.

Phospho-gypsum (PG) is a by-product generated from wet process of phosphoric acid production. The recycling rateof PG is only fifteen percents for the recycling uses, such as cement retardant, gypsum board, plaster, functional fertilizer.In the result of pH analysis, PG, neutralizing gypsum, soil, and dredged soil were 3.5, 7.4, 8 to 8.8, and 7.8, respectively.In case of the electric conductivity (EC), PG, neutralizing gypsum, and soil were 2,990µS/cm, 2,230µS/cm, and84~99µS/cm, respectively. In heavy metal contents of PG, As and Cd could be measured under environmentalstandards in Korean Soil Environment Conservation Act. In inorganic elements of leaching PG, Ca and Na were 629mg/L and 13 mg/L, respectively, but As, Cd, and other elements were detected under the regulated levels in Korean WasteManagement Act. Also, among inorganic elements in PG, the leaching ratio of Mg and Cd were 7.3%, 1.3% respectively.In neutralized PG, leaching ratio of Mg and Cu were 1.9%, 1.4% respectively compared with other elements. Insequential batch leaching test, the leaching concentrations of As and Cd were rapidly decreased after 2 days. F− andCa were steadily decreased until 2 days and 8 days, respectively, and no more change since then. In case of SO42−, itfell at constant rate to 1,600~1,800mg/L. As seen in Ca leaching curve relating to pH value, the leaching decreasedwith increasing pH.

Waste-gypsum of iron works was milled with CaO by planetary mill. TGA analysis of the ground material showed that the characteristics of pyrolysis after mechanical grinding was increased from 90% to 94% at 800℃. From the analysis of XRF the constituent of Na2O, SO3, Cl, PbO and ZnO were decreased while that of MgO, Al2O3, SiO2 and CaO increased a little. XRD analysis showed that high peak swere shown at PbO, PbCl2, PbO2 and Pb2O3 before mechanical treatment. After mechanical grinding of D-2, high peaks were shown at Pb3O4 and Pb5O8 showing the oxidation of Pb. These results showed that mechanochemical grinding in plnetarymill promoted to change chemical properties of waste gypsum of ironworks to oxydize the Pb component of waste gypsum of ironworks.

In this study, Blast furnace-based has been manufactured by utilizing recycled aggregates and gypsum as alkali activator. Comparing with the common geopolymer concrete, Using recycled aggregates and gypsum as activator could be identified to applied in low strength concrete.