• 제목/요약/키워드: Clinker

검색결과 273건 처리시간 0.027초

광화제 첨가가 포틀랜드 시멘트의 Tricalcium Silicate 생성에 미치는 영향 (Effects of Mineralizer Addition on the Formation of Tricalcium Silicate in Portland Cement)

  • 김인태;이창봉;김윤호
    • 한국세라믹학회지
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    • 제31권12호
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    • pp.1417-1422
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    • 1994
  • Effect of MgO, CaSO4, and CaF2 addition on the formation of clinker minerals in portland cement have been investigated by measuring the amounts of free-CaO and C3S in the fired specimens and analyzing the Mg and S concentration in C3S and C2S. It was found that CaSO4 inhibited C3S formation but MgO addition offset this effect of CaSO4. MgO addition also enhanced the mineralizing effect of CaSO4+CaF2, resulting in the acceleration of C3S formation. It was suggested that Mg might inhibit the formation of sulphate compounds rim around C2S and thus C2S+CaOlongrightarrowC3S reaction was facilitated.

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Hardening Properties of Activated Calcium Dialuminate Clinker with Phosphoric Acid Solution

  • Song, Tae-Woong;Kim, Sei-Gi
    • The Korean Journal of Ceramics
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    • 제3권4호
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    • pp.235-238
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    • 1997
  • Basic properties of new cement pastes based on the system $CaO-Al_2O_3-P_O_5-H_2O$were studied Phosphoric acid solutions and calcium dialuminate clinkers synthesized by the hydration-burning method were used for liquid and powder components of the paste, respectively Variation in the compositions of the paste was achieved by changing the liquid/powder ratio and the concentration of phosphoric acid solution. The hardening rate of the paste was so largely affected by the amount of phosphoric acid that hardening was inhibited with the low-concentrated solution but was explosively accelerated with the high-concentrated solution. The phosphoric acid solutions of concentration of 45~50% and the liquid/powder ratio of 0.5~1.5 were favoured for the high early-strength cement paste with the reasonable hardening rate and high strength. The binding phase of hardened paste was the dense amorphous gel of the system $CaO-Al_2O_3-P_O_5-H_2O$. in which the unreacted calcium dialuminate grains were embeded.

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Cement의 수화반응 물리특성에 미치는 ZnO의 영향 (The Effect of ZnO on the Hydration Reaction and Physical Properties of Cement)

  • 김홍기;추용식;이경희;송명신
    • 한국세라믹학회지
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    • 제34권4호
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    • pp.399-405
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    • 1997
  • With the increase of ZnO content, heat of hydration decreased. For specimens containing ZnO more than 0.6 wt.%, the compressive stength of cement cured for 28 days could not be measured because setting was not occurred. With the increase of ZnO content, Blaine specific surface area of cement was decreased and the residue of 45 ${\mu}{\textrm}{m}$ and 90 ${\mu}{\textrm}{m}$ was increased when cement was ground. That is, grindability became worse as ZnO increased in clinker. The difference of color as a function of ZnO content could not be observed, but in the excess of amount of ZnO added, color became more white and reddish yellow.

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시멘트 원료로서 폐.부산자원의 활용 (Utilization of Waste and Industrial Byproducts as a Raw Material in the Manufacture of Portland Cement)

  • 최상흘;박용완;지정식;오희갑
    • 한국세라믹학회지
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    • 제15권3호
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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.

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포틀랜드시멘트 클링커융액의 결정화에 관한 연구($K_2O$와 MgO의 영향) (Crystallization of the Liquid Phase in Portland Cement Clinker (Effects of $K_2O$ and MgO))

  • 한기성;문정연;김용국
    • 한국세라믹학회지
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    • 제19권3호
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    • pp.236-240
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    • 1982
  • The crystallization of melts with similar composition of Portland cement liquid containing 0-5% $K_2O$ was studied by differential thermal and isothermal reaction. The devitrification of melts was occured in stages, the recognizable amount of CaO was appered at the first step, then proto-C3A was crystallized. The latter showed to occur in both cubic C3A and Ca-ferrite crystallization. Batches lost remarkable amounts of $K_2O$ as a result of volatilization during melting and the solubility of $K_2O$ in the melts was unstable.

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콘크리트 고성재료의 수화발열 및 열적특성을 고려한 단열온도상승 예측에 관한 연구 (The estimation of adiabatic temperature rise of concrete considered hydration heat generation and thermal properties of constituents)

  • 손명수;강석화;이양수;박연동;김훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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    • pp.155-160
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    • 1998
  • In this study, the estimation method of adiabatic temperature rise of concrete was developed by using hydration heat generation of mineral compounds of clinker and pozzolans. Specific heat considered the effects of mix proportion and temperature was calculated with experimental data. The adiabatic temperature rise calculated by developed method were compared with experiments in which many types of cement and admixtures were used. As the results of this study, it was found that the developed method could calculate adiabatic temperature rise of concrete accurately without the experiment.

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Carbonation of Portland Cement Studied by Diffuse Reflection Fourier Transform Infrared Spectroscopy

  • Ylmen, Rikard;Jaglid, Ulf
    • International Journal of Concrete Structures and Materials
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    • 제7권2호
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    • pp.119-125
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    • 2013
  • Carbonation is a natural ageing process for cement. This study focuses on how the carbonation rate varies with selected hydration times and atmospheric conditions during the early stages of reacting dried cement paste. Diffuse reflection Fourier transform infrared spectroscopy is shown to be a suitable technique to monitor the formation of carbonates in cement. Combined with a previously developed freeze drying technique, carbonation can be studied at specific hydration stages. In ambient air both calcium hydroxide and calcium silicate hydrate (C-S-H) in cement are carbonated. Increased hydration time enhances the carbon dioxide uptake, which indicates that the calcium in the hydration products reacts more easily than the calcium in the clinker phase. In a humid $CO_2$ atmosphere, the carbonation process is so pronounced that it decomposes C-S-H into calcium carbonate and silica. In a moist $N_2$ atmosphere no carbonation occurs, but the sulfate chemistry of the cement seems to be affected due to the formation of ettringite.

열적성질을 고려한 콘크리트의 수화발열특성에 관한 연구 (The Effect of Thermal Properties on Temperature Development of Concrete)

  • 손명수;박연동;김훈;김호영;이양수;강석화
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.97-102
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    • 1997
  • In this study, a predictive method which was modified from KIshi's model for the temperature development of concrete was developed by using mineral compounds of clinker and pozzolans. Temperature dependent heat generation of reaction was also considered. Specific heat considering the effect of mix proportion and temperature was calculated with experimental data in the literatures. Thermal conductivity considering the effect of mix proportion and temperature was experimentally investigated. Through this research it was found that the developed method considering thermal properties accurately predicted adiabatic temperature rise of concrete without the experiment. It was also found that the thermal conductivity of concrete could be predicted by the volume ratio of each component of mix proportion and was independent of temperature within the normal climatic range.

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A Case Study of Desulphurization by Limestone Adsorbent in an Industrial CFBC Boiler

  • Park, Young-Goo;Kim, Seung-Ho;Jo, Young-Min
    • Journal of Korean Society for Atmospheric Environment
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    • 제21권E2호
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    • pp.67-74
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    • 2005
  • Domestic anthracite contains a large amount of fine particles, which causes to fire the back side of the boiler and to form the clinker deteriorating the combustion efficiency. At this time, the fine limestone adsorbents for a desulphurization agent may be used to facilitate an aggravation of the boiler, so that fine mode of limestone (<0.1mm) has been used no more than $25\%$ in local power stations of Korea. The present test carried out with an in-situ boiler, however, showed that higher content $(up\;to\;50\%)$ of fine limestone particles did not entail any mal-function. In addition, the desulphurization was found to be as good as the old mode of limestone adsorbents.

포틀랜드 석회석 시멘트에 관한 XRD 분석 (XRD Analysis of Portland Limestone Cement Paste)

  • 방미진;신기수;박기봉
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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    • pp.189-190
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    • 2018
  • This study produced Portland limestone cement at the rate of limestone substitution by grinding limestone and clinker together, and it conducted an XRD analysis to determine the sign language response structure as a basic study on Portland Limestone Cement. As a result of the XRD analysis, the higher the substitution rate of limestone, the more likely it is that the detection rate of ettringite is decreased. Additionally, we could see that the production volume of Mono-carbonate was increasing.

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