• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.6
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• pp.210-215
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• 2023

Raw mix burnability is an especially crucial factor in cement manufacturing technology, and it depends on the physical, chemical and mineralogical properties of each raw material. In this article, we compared the difference of burnability between the domestic and Japanese fly ash as cement raw materials by using Lafarge and Polysius evaluation method. Regardless of the type or amount of fly ash used, it was found to be more combustible when using fly ash. In both case, burnability improves as the amount of fly ash increases, especially the improvement in bunarbility is remarkable up to 3%. In conclusion, as the amount of fly ash increases within the range allowed by cement quality, burnability of raw materials improves, and thus the fuel cost required for the firing of clinker can also be expected to be reduced.

• Journal of the Korean Ceramic Society
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• v.19 no.1
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• pp.35-43
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• 1982

It was found that the burnability of raw mix and characteristics of clinker was affected by the difference in grades of limestones. The thermal decomposition temperature of raw mix which used low grade limestone was lower than that of high grade, and the fast formation of $C_2S$ was due to the rich content of calcite and quartz over critical grain size, which caused the bad effects in the burnability, but $C_3S$ was formed slowly. The structure of clinker had many pores, and the growth of clinker minerals was inferior.

• 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.

• Journal of the Korean Ceramic Society
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• v.22 no.1
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• pp.25-34
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• 1985

The states of alkali occuring in Portland cement clinker were studied. Potassium was added to raw mixture by there kinds ; $K_2SO_4$, $K_2CO_3$ and KOH. In case of $K_2CO_3$ and KOH addition the new state of unstable alkali was found when alkakli content is high and $SO_3$ content is low in the clinker. Unstable state of highly basic free 4K_2O$ causes lowering burnability much more than alkali sulfate especially at the early stage of burning. Lowered burnability by 4K_2O$ became more serious with higher LSF. Unstable free-4K_2O$ which is readily soluble with water reacts with gypsum to form $Ca(OH)_2$ and syngenite as soon as water is added. As a results the liberation rate of heat of hydration at the early hydration process(1st peak) was increased.

• Journal of the Korean Ceramic Society
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• v.15 no.3
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• pp.149-156
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• 1978

The utilization of waste and industrial byproduct materials, such as blast furnace slag, shales, poor coal and anthracite briquet ash, were investigated as a source of calcareous or argillaceous material in the manufacture of Portland cement. As a slag is similar to cement in chemical compoment and contains about 40∼50% of CaO, it's utilization in cement manufacture should be suitable. The burnability was increased and the heat of clinker formation was decreased by using slag. Some consideration should betaken in the use of large quantity because of sticking in suspension preheater kiln. Suitable quantities of colliery shales and poor coal should be useable in cement manufacture as a argillaceous materials and also its combustible materials should be utilized in cement manufacture. Anthracite briquet ash is also usable as a argillaceous source and it gives good burnability.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.294-301
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• 2020

This study evaluated the burnability and hydration reaction of clinker burned with high Al₂O₃ content OPC to apply large amounts of industrial by-products in the cement manufacturing process. Specifically, after preparing a clinker with a high C₃A content by burning the OPC raw material with a high content of Al₂O₃ in a laboratory electric furnace, the burnability of the clinker was evaluated through XRD Rietveld analysis and polarization microscopy, and clinker hydration reactivity was reviewed through the Isothermal conduction calorimetry analysis and the cement compressive strength. As a result, the kiln burning temperature for the production of high Al₂O₃ content clinker lower, and the compressive strength was equal to or higher than OPC. Therefore it was confirmed the possibility to manufacturing energy-saving high Al₂O₃ content clinker using a large amount of industrial by-products.

• Resources Recycling
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• v.13 no.3
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• pp.19-26
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• 2004

In order to use the mine tailing which was generated in the flotation process of scheelite ore into the raw material of ordinary portland cement, the characteristics of the prepared cement clinker was investigated. Scheelite mine tailing is composed of 68.8% of $SiO_2$, 8.6% of $Al_2$$O_3$, 10.8% of $Fe_2$$O_3$, 5.0% of CaO, respectively. It exists as $\alpha$-quartz, muscovite, clinochlore and has 8.0% of 88 $\mu\textrm{m}$ residue. When LSF, SM, and IM of the raw materials (such as limestone, convertor slag, fly ash, and mine tailing) are 91.0, 2.60, and 1.60, respectively, the burnability index of the raw materials is 50.7, the crystal size of $C_3$S and $\beta$-C$_2$S in the prepared clinker is 15∼35$\mu\textrm{m}$, and about 3.8% of scheelite mine tailing can be used as raw material.

• The Korean Journal of Ceramics
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• v.2 no.3
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• pp.147-151
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• 1996

By adding borax into the raw mix, Modified Belite Cement clinker and cements were prepared. Clinkerization and hydration reactions were investigated in order to better understand. Borax-bearing MBC clinker sintered at 1300℃ for 1 hour showed excellent burnability. Borax stabilized α'and β-C2S at room temperature. In the hydration of the cement prepared with the borax-bearing clinker, ettringite, monosulphate, C-S-H hydrates and CH were formed. The hydration of calcium sulphoaluminate was less reactive than the cement prepared with the controlled clinker at early hydration time. But, as hydration time elapsed, this cement showed more active hydraulicity and higher compressive strength development.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1757-1763
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• 2011

In recent years, accordance to industrial development project on railway investment, adverse environmental issues of the investment, such as disputed cases about recycling and usage of Ballast Cleaner excavated soil, have been continuously increasing. It will not only enhance the regulation of soil contamination but take considerable time and cost in future. In this study, we investigated soil contamination and burnability with soil of Chungang Line, Taebaek Line, Chungbuk Line, in order to seize a possibility of recycling Ballast Cleaner excavated soil for the natural materials and substantial heat sources, which are necessary resources for cement manufacturing process. As a result of this study, It is found that Ballast Cleaner excavated soil is satisfied with a standard. The excavated soil contains a lot of cement ingredients and fossil fuel dust incurred from freight transportation, so it is expected to use for ingredients of cement and replacement of heat sources.

• Journal of the Korean Ceramic Society
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• v.34 no.9
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• pp.949-956
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• 1997

With the increase of ZnO content, burnability of raw materials was improved and the formation of clinker minerals was accellerated. When ZnO was added 1wt%, the clinkering temperature was decreased about 30~5$0^{\circ}C$. As an increase of ZnO added, aluminate phase was decreased and ferrite phase was increased. When ZnO was added more than 3.0wt.%, the new phases, such as ZnO.Al2O3 and ZnO.Fe2O3 were formed. In the excess of amount of ZnO added, the decomposition of alite phase was intensed and the lamella structure in belite could not be observed due to the decomposition.