• Magazine of the Korea Concrete Institute
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• v.22 no.3
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• pp.36-40
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• 2010

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.235-236
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• 2003

시멘트 업계에서 필연적으로 다량 배출되는 질소산화물(NOx)의 법적 규제치는 350ppm(산소 농도 13% 기준)이나 대부분의 시멘트 사업장에서 기준치를 초과하여 배출되고 있는 실정이다. 시멘트 산업은 석회소성로의 고온운전과 다량의 연료사용 등 시멘트 제조의 공정특성상 타 산업에 비해 많은 질소산화물을 배출하여 왔으나, 사업장 주변지역 환경에 질소산화물이 미치는 영향에 관한 연구가 전혀 이루어지지 않아 이에 대한 자료가 전무한 실정에 있다. (중략)

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.75-84
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• 2021

In this study, the correlation between cement quality(chemical composition, mineral composition, and compressive strength) and amount of waste alternative fuels used in the cement manufacturing process and was investigated. Cement manufacturing facility using coal, soft plastics(plastics that are easily scattered by wind power, such as vinyls), hard plastics(plastics that do not contain foreign substances, waste rubber, PP, etc.) and reclaimed oil was analised. Data was collected for 3 years from 2017 to 2019 and let the amount of fuels used as an independent variable and cement quality data as a dependent variable. As a result, depending on the type and quality of the alternative fuel has not a significant effect on the chemical composition(Cl and LSF) and mineral composition(f-CaO, C3S contents). Contrary to the concern that the compressive strength of cement would decrease, there was a significant positive correlation between amount of alternative fuel used and cement compressive strength.

• Journal of Korea Fair Competition Federation
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• no.97
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• pp.65-71
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• 2003

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.257-263
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• 2008

We have examined explosion characteristics of bituminous coal dusts in cement manufacturing process. In order to find the thermal properties, we investigated weight loss and ignition temperature of coal materials using TGA and DSC. Also specific surface area of dust was investigated. Dust explosion experiments with Hartman's dust explosion apparatus have been conducted by varying concentration and size of coal dust for explosion probability and lower limit explosion concentration. According to the results for thermal properties, there is a little change by dust size. However, the specific surface area of dust is increased by decreasing dust size. The explosion test results show that small size and increasing concentration of dusts make dust explosion easier. And we find that the lower limit explosion concentration of bituminous coal is $0.3mg/cm^3$ and the probability is 100% on $0.9mg/cm^3$ in 170/200 mesh used in cement manufacturing process.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.749-755
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• 2004

Fluosilicic acid ($H_2SiF_6$) is recovered as aqueous solution which absorbs $SiF_4$ produced from the manufacturing of industrial-graded $H_3PO_4$ or HF. Generally, fluosilicate salts prepared by the reaction between $H_2SiF_6$ and metal salts. Addition of fluosilicate salts to cement endows odd properties through unique chemical reaction with the fresh and hardened cement. In this study, two-component fluosilicate salt based chemical admixtures (MZ) of $4\%,\;6\%$, and $8\%$ concentration were prepared by the reaction of $H_2SiF_6$ ($25\pm2\%$) and metal salts. The effect of concentration of MZ at a constant adding ratio on the hydration and watertightness of cement were investigated respectively. In a cement containing MZ, metal fluorides such as $CaF_2$ and soluble silica by hydrolysis were newly formed during hydration. The total porosity of the hardened cement was lower in the presence of U because of packing role of metal fluoride and pozzolanic reaction of soluble $SiO_2$. Consequently, the watertightness of the hardened paste containing MZ was more improved than non-added (plain) due to an odd hydration between cement and MZ.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.06a
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• pp.109-110
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• 2009

"드럼 코아시편 채취장치" 는 침출/내수성 시험, 압축강도 측정시험, 열 순환 시험등 의 파괴적 물성시험을 수행하기 위해서 경질(시멘트 고화체) 및 연질(파라핀왁스) 등의 방사성폐기물드럼으로부터 코아 시료를 채취하는 장비이다, 시편채취의 최대길이는 860 mm 이며 코아 시편의 직경은 50~200 mm 이며 일반적으로 "방사성폐기물 고화체의 물성시험"에 사용되는 시편은 실험실적으로 제조한 소규모 모의 고화체 시편과 고화공정에서 직접 채취한 소규모 시편, 200L 드럼으로부터 코아시편을 채취 가공하여 만든 시편과 같이 3종류가 있다. 고화공정에서 발생되는 고화체는 일반적으로 200 L 드럼에 주입되며, 고화체의 균일성 정도는 고화공정의 특성, 폐기물/고화매질 혼합비, 200 L 고화체 드럼의 냉각방식에 따라 다르다. 따라서, 실험실에서 제조한 시편과 공정에서 채취한 소규모시편은 실제 고화공정을 대표할 없으며 또한 실제 발생된 고화체의 조성과도 동일하다고 볼 수 없다. 따라서 200 L 드럼으로부터 코아시편을 채취하여 만든 시편이 고화공정과 고화체를 대표할 수 있는 시편으로 볼 수 있다 그러므로 고화체 및 고화공정을 대표할 수 있는 코아시편을 채취할 수 있는 장치를 제작하여 다양한 코아시편을 200 L 고화체 드럼으로부터 수직 코아시편을 채취할 필요가 있으며 실험에서 코아시편 채취속도와 연관된 Z-AXIS 의 Rpm은 운전범위는 0-2000 Rpm 이나 이때 너무 빠른 속도는 기계에 치명적인 손상을 초래 할 수 있으므로 위험한 것으로 나타났으며 500-1000 Rpm 의 속도가 적합한 것으로 시험되었으며 시편을 절삭하는 Spindle의 Rpm은 운전범위는 0-1500Rpm 이나 무리한 운전을 피해 가장 적절한 Speed로 운전해야하며 시험결과 500-800Rpm 이 최적운전범위로 나타났다 또한 시멘트고화체에서의 코아 채취시험에서는 Spindle의 속도는 500 Rpm, Z -AXIS 의 Rpm은 900 Rpm이 가장 적합한 것으로 나타났으며 성능평가시험을 통하여 비트부의 절삭속도와 Z축의 이동속도에 관한 그라프를 획득하였으며 시편의 크기에 따라서 Spindle의 속도를 증감하여야함을 확인할 수 있었다.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.329-330
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• 2009

This study is to investigate the effect of the combined use of fly ash(FA) and coarse particle cement(CC) collected in particle classification process of ordinary Portland cement(OPC) manufacturing on the hydration exothermic and strength development in the field application.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.549-552
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• 2008

The cement is accomplished with CaO, SiO2, Al2O3 and Fe2O3, etc. After pulverizing materials of the limestone, the sand and the clay(shale), iron ore, the cement becomes clinker materials sintering from the rotary kiln of oxidizing atmosphere. The part in the materials of the clinker is substituted with slag, sludge etc. and it is used. because The chromium which is to be included in the clinker materials, in sintering process hexavalent chromium is converted with the chrome. Consequently it changed the type and a content of clinker materials and test hexavalent chromium of the clinkers which is manufactured.

• New & Renewable Energy
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• v.4 no.2
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• pp.81-86
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• 2008

Rotary kiln in cement work has been evaluated for a wide variety of organic wastes such as wood, used tyres, plastic wastes and automobile shredder residue (ASR). However the presence of chlorine hampers the use of ASR as fuel in rotary kiln. Therefore, the behavior characteristics of chlorine components in rotary kiln should be considered to develop an effective method for ASR treatment to recovery energy resources. The aim of this paper is to present the chlorine control system applied to a cement manufacturing process for ASR use as an alternative fuel. In this work, the simulation of bypass unit and cyclones for chlorine control in rotary kiln has been studied and compared with the operation results of field test.