• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.589-594
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• 2011

Raw mix of molten clinker was fabricated using blast furnace slag as starting material. Raw mix was melted at 1620$^{\circ}C$ for molten clinker fabrication. It was found that molten clinker contained alite and belite equivalent to OPC clinker mineral by optical microscope and SEM. The size of alite was 10~50 ${\mu}m$ and that of belite was 20~80 ${\mu}m$. This result thought to be attributed low $Al_2O_3$ content and cooling condition. Interstitial phase increased with blast furnace slag content and gehlenite was formed by the condition of LSF and SM. So raw mix with 27~41% blast furnace slag could be converted into cement clinker by appropriate choice of melting andcooling methods in this study.

• Resources Recycling
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• v.20 no.6
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• pp.71-77
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• 2011

Raw mix of molten clinker was fabricated using blast furnace slag as starting material. Raw mix was melted at 1620 for molten clinker fabrication. Color and mineral composition of molten clinker was investigated by XRD and colorimeter. It was found that the molten clinker contains alite and belite equivalent to OPC clinker mineral and shows higher whiteness value than that of OPC. Whiteness of the molten clinker decreased with LSF and SM. Also the whiteness value of the slag cement using molten clinker was higher than that of common slag cement.

• Resources Recycling
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• v.29 no.6
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• pp.48-56
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• 2020

In this study, raw mix was mixed with CaCl2 for analyzing characteristics of clinker added chlorine and chlorine was added by 2,000ppm at high concentration condition. The raw mix added chlorine was burned at 1250℃~1350℃ and maintained during 10minutes at each maximum temperature. Clinker target modulus was LSF 92, SM 2.5 and IM 1.6 in this study. The burnability of clinker added chlorine was identified by free-CaO content. Free-CaO content decreased as chlorine content increased and free-CaO content of 1350℃-2000ppm clinker decreased by 1.5%. Optical microscope and XRD Analyses were used for identify mineral properties of clinker added chlorine. The mineral of clinker could not be observed at 1250℃ and the size of alite grew larger as chlorine content increased at 1350℃. It showed a good crystallizability as chlorine content increased. As chlorine content of clinker increased, clinker showed a good burnability and mineral property.

• Resources Recycling
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• v.18 no.3
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• pp.49-54
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• 2009

The effect of MgO in synthesis of alinite clinker was investigated. Clinker of alinite composition ratio and alintite clinker substituted for MgO of 3.77% were sintered at $760^{\circ}C$ and between $800^{\circ}C$ and $1,400^{\circ}C$ at the interval of $100^{\circ}C$. Synthesized phases and hydration heat of alinite clinker with MgO and without MgO were then investigated. As a result, alinite, CCA, ${\beta}-C_2S$ and f-CaO phases are synthesized in alinite clinker without MgO sintered at $1,300^{\circ}C$, while only alinite phase is synthesized in alinite clinker with MgO sintered at $1,300^{\circ}C$ with the highest synthesis rate. Heat evolution of alinite clinker with MgO has no induction period.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.483-488
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• 2007

The influence of $P_2O_5$ on clinker mineral composition and the cement quality was investigated. When the sewage sludge was used as a raw material in place of clay, the presence of $P_2O_5$ in sewage sludge affects the mineral composition and the clinker quality. As the $P_2O_5$ concentration in raw mix increases, the burnability of clinker becomes worse and the alite decomposes into belite and free-CaO, so belite increases with the decrease of alite. The early strength of mortar decreases with the increase of $P_2O_5$ concentration. On the other hand, later-age strength increases with the increase of belite content. The setting time of cement was delayed with the $P_2O_5$ concentration above 0.6 wt%.

• Journal of the Korean Ceramic Society
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• v.23 no.2
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• pp.64-70
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• 1986

In this investigation x-ray diffraction method was mainly studied for quantitative analysis of clinker mineral composition. And also optical microscopic observation and Bogue calculation method were applied to compare with the x-ray diffraction method. In the procedure of x-ray diffraction analysis graphite monochromator automatic divergence slit and spinner for sample holder were used for minimizing the error due to the operation of the equipment. Especially the separation of overlapped peaks were proceeded by micro-processor automatically. The results of x-ray diffraction method for synthesized clinker were consistent with the Bogue value and the results of optical microscopic observation. However the results of quantitative analysis of mineral composition or commercial clinker containing solid solution of minor component were different from the Bogue value. On the other hand they agreed reasonably well with results of the optical mic-roscopic observation.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.581-585
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• 2001

Alinite-Calciumchloroaluminate system clinker was synthesized from solid state waste. The raw materials were municipal incineration ash, sewage sludge, limestone and clay. ecocement was prepared by the mixing of synthesized clinker and optimum amount of gypsum and its hydrolysis characteristic was investigated. X-ray diffraction, conduction calorimeter and reflecting microscope were used to analyze structural and physical properties. The main phase of clinker were alinite, calcium chloroaluminate. $C_2$S, $C_3$S. From the results of hardening time, hydration reactivity of synthesized all samples was faster than that of ordinary portland cement.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.804-810
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• 2003

The fine powder produced by heating and grinding of the waste concrete in the waste construction was investigated whether utilize as substitution raw material of SiO$_2$, CaO, and Al$_2$O$_3$ source for OPC clinker manufacture is possible or not. In order to synthesize OPC clinker, limestone, shale, converter slag and fly ash were used as main raw materials, and modulus was fixed LSF 91.0, SM 2.60, IM 1.60. The synthesized clinkers were characterized. The Main products of synthesized clinker were C$_3$S, ${\beta}$-C$_2$S, C$_3$A, C$_4$AF as OPC clinker at 1,43$^{\circ}C$. As a result of TG-DTA and burnability index(B.U) analysis of each raw mixtures, the formation temperature of clinker phases was similar and B.I was showed easy burning as 48.6∼51.4.

• Journal of the Korean Ceramic Society
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• v.41 no.4
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• pp.323-327
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• 2004

This study has been carried out to use the municipal solid waste sewage sludge ash generated at sewage disposal field as the raw materials of Ordinary Portland Cement (OPC). Limestone, shale, converter slag, and fly ash were used as the main raw materials. After the raw materials were mixed, these were fired at 1,300, 1,350, 1,400, 1,450, and 1,500$^{\circ}C$ for 1 h and cooled rapidly in air. The properties of clinker synthesized were examined with XRD, SEM, and burnability index by polysius method.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.553-560
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• 2021

In this study, cement clinker using a pure sample and clinker using 7% coal ash were sintered at a temperature of 1050~1500℃. Changes in the content of cement minerals and changes in microstructure by sintering temperature were reviewed. The application of coal ash as a raw material for cement clinker was applicable as a source of Al₂O₃ and SiO₂. At a sintering temperature of 1350℃ or higher, the cement clinker applied with coal ash showed the same level of mineral content as compared to the cement clinker applied with pure raw material. The microstructure also showed a similar state, confirming that coal ash can be used as a raw material for cement. In XRD-Reitveld analysis, a maximum amount of Belite was produced at 1250℃. The conversion from Belite to Alite was observed from 1350℃. From 1350℃, the interstitial phase and the mineral phase presumed to be alite were distinguished. It was clearly distinguished from 1400℃. As the sintering temperature increased, the shape and boundary of the crystal phase became clear, and the size of the crystal phase was also increased.