• Journal of the Korea Concrete Institute
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• v.13 no.2
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• pp.114-122
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• 2001

The purpose of this study was to manufacture sintered lightweight aggregate using paper sludge ash and to evaluate the qualities of the aggregate according to various mix proportions, conditions of pelletization and sintering. The paper sludge ash alone, due to its mineral and chemical compositions could not gain suitable expansion and strength. Hence, it was essential to add mineral additives such as clay, fly ash etc. The optimum muting ratio range determined in this study is as follows , paper sludge ash 30∼50 %, clay 30∼50 %, fay ash 0∼40 %, Paper sludge 0∼10% and hematite 2∼3 %(for manufacturing lightweight aggregate both for non-structural and structural concrete). It was possible to manufacture various lightweight aggregate whose dry specific gravity ranged about from 0.6 to 1.4 by using this optimum mixing ratio. From the test results of the qualities of aggregate, it showed that the 10% granules crushing value test and water absorption percentage ranged about 5∼10 ton and 10∼20%. Thus, it was favorably comparable to those of the imported aggregate. The manufactured lightweight aggregate could be used for structural concrete and non-structural concrete.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.2
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• pp.96-99
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• 2016

This study characterized fly ash produced from a sewage sludge incineration facility in Korea to determine if the byproducts can be utilized. All the incinerated sewage sludge was from a city in Korea. To characterize fly ash and to determine if it can be utilized, pH, water contents, elemental components, particle size, surface morphology, heavy metal compositions, and others were analyzed. In average, pH was 6.2, and water contents was about 5%. T-N and $T-P_2O_5$ were 3% and 24.5%, respectively. Particle size averaged 836 nm; surface morphology did not exhibit any significant results. X-ray diffraction (XRD) analysis results revealed that major components of the fly ash were $P_2O_5$, CaO, MgO, $K_2O$. Composition of heavy metals by the Korea Standard Methods for Waste Quality did not exceed the criteria for specified wastes in Korea.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.37-41
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• 2000

폐기물 소각시 발생되는 각종 유해가스 및 비산회재(fly ash)는 후처리 설비에 의해 배출허용기준치 이하로 처리된 후 대기 중으로 방출되도록 환경 규제되고 있다. 그러나 포집된 비산회재(fly ash) 및 노하부 배출재(bottom ash) 내에는 미 연소된 상태로 배출된 유해성 유기물질(다이옥신, 퓨란류 등)과 중금속 성분이 함유되어 있어 이들 소각잔류물(incineration residues)을 안정화나 무해화 처리 없이 단순 매립할 경우 강우에 의해 소각잔류물 내의 유해성분이 침출됨에 따라 토양이나 지하수 등에 2차 환경오염을 일으키게 된다. (중략)

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.589-594
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• 2006

The recycling of industrial wastes in the concrete manufacturing is of increasing interest worldwide, due to the high environmental impact of the cement and concrete industries and to the rising demand of infrastructures, both in industrialized and developing countries. The production of municipal wastes in the South Korea is estimated at about 49,902 ton per day and only 14.5% of these are incinerated and principally disposed of in landfill. These quantities will increase considerably with the growth of municipal waste production, the progressive closing of landfill, so the disposal of municipal solid waste incinerator(MSWI) ashes has become a continuous and significant issue facing society, both environmentally and economically. MSWI ash is the residue from waste combustion processes at temperature between $850^{\circ}C\;and\;1,000^{\circ}C$. And the main components of MSWI ash are $SiO_2,\;CaO\;and\;Al_2O_3$. The aim of this study is to find a way to useful application of MSWI ash(after treatment) as a structural material and to investigates the hydraulic activity, compressive strength development composition variation of such alkali-activated MSWI ashes concrete. And it was found that early cement hydration, followed by the breakdown and dissolving of the MSWI-ashes, enhanced the formation of calcium silicate hydrates(C-S-H). The XRD and SEM-EDS results indicate that, both the hydration degree and strength development are closely connected with a curing condition and a alkali-activator. Compressive strengths with values in the 40.5 MPa were obtained after curing the activated MSWI ashes with NaOH+water glass at $90^{\circ}C$.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.2
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• pp.114-118
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• 2009

With the advance of industrialization and urbanization, a lot of waste has been discharged and treated by incineration. But fly and bottom ashes are generated in this process. In addition, the treatment method to recycle sewage sludge and melting slag is required to manage these wastes. The objective of this research was to prepare of multi-functional brick which were made from MSWI (Municipal solid wastes incinerator) fly ash, sewage sludge and slag. The bricks were made by mixing raw materials and then drying for 24 hours. Next, they were dried for 24 hours at $160^{\circ}C$ and fired for 2 hours. Calcination temperature was changed to discuss the effect of temperature from $1,080^{\circ}C$ to $1,130^{\circ}C$. Compressive strength of a brick was creased with the increase of temperature. To increase mixing ratio of fly ash and slag reduce the compressive strength the optimal condition was the mixing ratio of fly ash : melting slag : sewage sludge : clay as 10 : 20 : 5 : 65 and $1,150^{\circ}C$ of calcination temperature. Compressive strength was obtained as about 41 MPa at this condition.

• Resources Recycling
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• v.16 no.2 s.76
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• pp.32-39
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• 2007

The measurement of physicochemical properties of ASR incineration ash has been carried dot and the preparation of light-weight material has also been performed using ASR ash for recycling point of view as building or construction materials. For this aim, chemical composition, particle size distribution, and heavy metal leachability were examined for 2 bottom ashes and 4 fly ashes obtained from the domestic ASR incinerator. In the present work, attempt has been made to prepare the lightweight material using boiler ash as a raw material, which is prepared by forming the mixture of boiler ash, lightweisht filler and inorganic binder and followed by calcination at elevated temperature. As a result, the content of Cu in bottom ash was as high as about 3wt% so that the recovery of Cu from ash was required. The major compound of SDR #5 and Bag filter #6 was found to be $CaCl_2{\cdot}Ca(OH)_2{\cdot}H_2O\;and\;CaCl_2{\cdot}4H_2O$, respectively. It is thought that heavy metal teachability of lightweight material prepared with boiler ash was significantly decreased due to the encapsulation or stabilization of heavy metal compounds.

• Journal of the Korean Ceramic Society
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• v.38 no.9
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• pp.811-816
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• 2001

The influence of the incinerated ash and additives on glass phase formation of lightweight aggregate, weight-lightening, and the bloating mechanism was investigated. Clay was used as base materials and incinerated ash was added from 0 to 30wt%. The additives such as $Na_2CO_3,\;CaCo_3,\;K_2CO_3,\;MgCO_3$, and a little amount of waste oil were added to the mixed body. In clay/incinerated ash/additive system, it turned out that $CaCO_3\;and\;MgCO_3$ were the components for glass phase formation and $Na_2CO_3$ was the component for both glass phase formation and weight-lightening. The small addition of waste oil from 0.5wt% to 3.0wt% affect on the bloating of aggregate. Incinerated ash had a good effect on the glass phase controlling. The most effective condition controlling glass phase and bloating of aggregate was 10wt% incinerated ash, 2wt% waste oil at 1200$^{\circ}$C. The bloating mechanism of lightweight aggregate is as follows; 1) micro-crack formation caused by thermal-shock and gas generation from inside of aggregate, 2) volume expansion by glass phase formation on the aggregate surface and rapid gas bloating inside of aggregate, 3) densification after bloating.

• Applied Chemistry for Engineering
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• v.17 no.2
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• pp.163-169
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• 2006

A Life Cycle Assessment (LCA) study was carried out to identify and improve the environmental aspects associated with the present incineration system of spent Li-ion batteries (LIBs) in Korea. The environmental impact associated with the landfill of the incineration ash was also assessed in this study, while so far it was excluded in most studies. It was found out that the $CO_{2}$ emission from the electricity generation as well as the incineration process and heavy metals emissions to air and water accounted for about 90% of total environmental impacts. In particular, the effect of the emission of heavy metals were dominant. In oder to improve the current incineration system environmentally, it is needed to incinerate the wastes like spent LIBs which contained relatively high portion of heavy metals separately from other combustible wastes. On the other hand, the effect of the landfill of ash after incineration was insignificant since the ash from the incineration process was chemically stable.

• Bulletin of Korea Environmental Preservation Association
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• v.29 s.371
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• pp.42-44
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• 2007

• Journal of Korean Society of Environmental Engineers
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• v.36 no.12
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• pp.843-850
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• 2014

This study investigated to recycle ash produced in the sewage sludge incinerator using reduction/stabilization. Nonsintering process was performed by binding cement, geobond and sand mixed with sewage sludge ash (SSA). Results showed that unconfined compressive strength could be obtained components of sewage sludge ash. it exceeded more than double score of the 22.54 Mpa ($229.7kg/cm^2$) Korean standard. chemical ingradients of the sewage sludge ash was mainly composed of $SiO_2$, $Al_2O_3$, $Fe_2O_3$, CaO and others, which were similar to those of the each binders consisting cement and geobond. microstructure of solidified speceimen for the different admixture was related to the compressive strength according to SEM analysis. optimum mixing range of the sewage sludge ash to inorganic binder was found to be 10~40% which can widly safely regulate the confined compressive strength. This study revealed the sewage sludge ash can be partial replacement of the inorganic binder for recycling.