• Title/Summary/Keyword: ash values

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Adsorption characteristics of lead ion in aqueous solution by volcanic ash (화산재에 의한 수용액의 납 이온 흡착특성)

  • Kim, Mi-Yeon;So, Myeong-Gi;Kim, Yeong-Gwan
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.3
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    • pp.359-366
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    • 2011
  • The feasibility of using volcanic ash for lead ion removal from wastewater was evaluated. The adsorption experiments were carried out in batch tests using volcanic ash that was treated with either NaOH or HCl prior to the use. Volcanic ash dose, temperature and initial Pb(II) concentration were chosen as 3 operational variables for a $2^3$ factorial design. Ash dose and concentration were found to be significant factors affecting Pb(II) adsorption. The removal of Pb(II) was enhanced with increasing volcanic ash dose and with decreasing the initial Pb(II) concentration. Pb(II) adsorption on the volcanic ash surface was spontaneous reaction and favored at high temperatures. Calculation of Gibb's free energy indicated that the adsorption was endothermic reaction. The equilibrium parameters were determined by fitting the Langmuir and Freundlich isotherms, and Langmuir model better fitted to the data than Freundlich model. BTV(base-treated volcanic ash) showed the maximum adsorption capacity($Q_{max}$) of 47.39mg/g. A pseudo second-order kinetic model was fitted to the data and the calculated $q_e$ values from the kinetic model were found close to the values obtained from the equilibrium experiments. The results of this study provided useful information about the adsorption characteristics of volcanic ash for Pb(II) removal from aqueous solution.

Experimental Investigation of Clay Fly Ash Bricks for Gamma-Ray Shielding

  • Mann, Harjinder Singh;Brar, Gurdarshan Singh;Mann, Kulwinder Singh;Mudahar, Gurmel Singh
    • Nuclear Engineering and Technology
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    • v.48 no.5
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    • pp.1230-1236
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    • 2016
  • This study aims to determine the effect of fly ash with a high replacing ratio of clay on the radiation shielding properties of bricks. Some interaction parameters (mass attenuation coefficients, half value layer, effective atomic number, effective electron density, and absorption efficiency) of clay fly ash bricks were measured with a NaI(Tl) detector at 661.6 keV, 1,173.2 keV, and 1,332.5 keV. For the investigation of their shielding behavior, fly ash bricks were molded using an admixture to clay. A narrow beam transmission geometry condition was used for the measurements. The measured values of these parameters were found in good agreement with the theoretical calculations. The elemental compositions of the clay fly ash bricks were analyzed by using an energy dispersive X-ray fluorescence spectrometer. At selected energies the values of the effective atomic numbers and effective electron densities showed a very modest variation with the composition of the fly ash. This seems to be due to the similarity of their elemental compositions. The obtained results were also compared with concrete, in order to study the effect of fly ash content on the radiation shielding properties of clay fly ash bricks. The clay fly ash bricks showed good shielding properties for moderate energy gamma rays. Therefore, these bricks are feasible and eco-friendly compared with traditional clay bricks used for construction.

Cementing Efficiency of Fly-ash in Mortar Matrix According to Binder-Water Ratio and Fly-ash Replacement Ratio

  • Cho, Hong-Bum;Jee, Nam-Yong
    • Journal of the Korea Institute of Building Construction
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    • v.12 no.2
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    • pp.194-202
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    • 2012
  • This paper predicts the cementing efficiency of fly-ash(FA) based on mortar test considering binder-water ratio and FA replacement ratio as experimental variables. The cementing efficiency prediction model proposed by statistical analysis enables us to estimate the value according to the binder-water ratio and FA replacement ratio of matrix. When FA replacement ratio is the same, the lower the binder-water ratio, the higher the estimated cementing efficiency. There are significant differences in the values according to binder-water ratio at FA replacement ratios of 15% or less, but there are almost no differences when FA replacement ratio is more than 15%. As the binder-water ratio increases, the variations in the values according to FA replacement ratio are great at FA replacement ratios of 15% or less. As the FA replacement ratios increase, the values increase for FA replacement ratios of 15% or less, but decrease for more than 15%. The values range from -0.71 to 1.24 at binder-water ratio of 1.67-2.86 and FA replacement ratio of 0-70%. The RMSE of the 28-day compressive strength predicted by modified water-cement ratio is 2.2 MPa. The values can be trusted, as there is good agreement between predicted strength and experimental strength.

Caesdpinia Sappan Natural Dyeing using Camellia Ash Solution and Rice Straw Ash Solution as Mordants (동백나무 잿물과 볏짚 잿물을 매염제로 사용하는 소목 천연염색)

  • Seo, Hee-Song;Jeon, Dong-Won;Kim, Jong-Jun
    • Journal of the Korean Home Economics Association
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    • v.43 no.8 s.210
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    • pp.1-12
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    • 2005
  • Ash solutions derived from vegetation have been known for their good mordanting action. They are used as finishing agents because they are able to promote dye uptake. It is expected that the types of ash solutions may have been different worker by worker since the workers have employed easy-to-get plants, when we reviewed old literature. However, the ash solutions are being used without clear distinctions between their characteristics. In this study, camellia ash solution and rice straw ash solution were prepared according to traditional methods. Using these solutions as mordanting agents, natural dyeing experiments with Caesdpinia Sappan were peformed. Following the dyeing procedure, the effect of the type of ash solution on the color of the dyed fabric was evaluated. The results showed that the ash solution mordanting effect us not dependent upon the components of the ash solution. It was also demonstrated that the mordanting effect was not based on the action of the metallic ions in the ash solution. The pH values of the ash solutions were adjusted in order to investigate the effect of changes in ash solution alkalinity on the dyeing process. The pH values ranged from neutral or weak acidity to the alkaline range in order to evaluate the characteristics of the mordanting tv the ash solutions.

Estimation of Compressive Strength of Fly Ash Concrete subjected to High Temperature (고온조건하에서 플라이애시를 사용한 콘크리트의 압축강도증진 해석)

  • Han Min-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.6 no.3 s.21
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    • pp.99-105
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    • 2006
  • In this paper, the estimation of compressive strength of concrete incorporating fly ash subjected to high temperature is discussed. Ordinary Portland cement and fly ash cement(30% of fly ash) were used, respectively. Water to binder ration ranging from 30% to 60% and curing temperature ranging from $20^{\circ}C{\sim}65^{\circ}C$ were also adopted for the experimental parameters. According to results, at the high temperature, FAC had higher strength development at early age than OPC concrete and it kept its high strength development at later age due to accelerated pozzolanic reaction subjected to high temperature. For strength estimation, Logistic model based on maturity equation and Carino model based on equivalent age were applied to verify the availability of estimation model. It shows that fair agreements between calculated values and measured values were obtained evaluating compressive strength with logistic curve. The application of logistic model at high temperature had remarkable deviations in the same maturity. Whereas, the application of Carino model showed good agreements between calculated values and measured ones regardless of type of cement and W/B. However, some correction factors should be considered to enhance the accuracy of strength estimation of concrete.

Effects of the pH Change of Ash Solution and the Addition of Chitosan on the Caesalpinia sappan Dyeing in the Simultaneous Mordanting with the Addition of Ash Solution (잿물 동시매염에 의한 소목의 염색에서 잿물의 pH 변화와 키토산 첨가가 염색성에 미치는 영향)

  • Seo, Hee-Sung;Jeon, Dong-Won;Kim, Jong-Jun
    • The Research Journal of the Costume Culture
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    • v.13 no.5 s.58
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    • pp.686-698
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    • 2005
  • In this study, simultaneous mordanting method of dyeing in the Caesalpinia sappan dye liquor mixed with the rice straw ash solution was employed. The dyeing effects were compared and reviewed according to the changes of dyeing mechanisms of pre-mordanting and simultaneous mordanting using ash solutions. By the direct addition of the ash solution, the pH of the liquor was abruptly changed. In the case of maintaining the pH value of the ash solution at about 7 or 8, compared to the pre-mordanting, $a^{*}$ values increased and $b^{*}$ values decreased. As a result, it is highly desirable in terms of selective emphasis on the reddish hue. The color development, differentiated from that obtainable by the dyeing of chitosan pre-treated fabric, was obtained due to the effect of the water soluble chitosan component on the dyeing mechanism.

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Strength and durability characteristics of bricks made using coal bottom and coal fly ash

  • Ashish, Deepankar Kumar;Verma, Surender Kumar;Singh, Joginder;Sharma, Namesh
    • Advances in concrete construction
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    • v.6 no.4
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    • pp.407-422
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    • 2018
  • The study evaluates properties of brick having coal ash and explores the possibility of utilization of coal bottom ash and coal fly ash as an alternative raw material in the production of coal ash bricks. Lower cement content was used in the investigations to attain appropriate strength and prohibit high carbon content that is cause of environmental pollution. The samples use up to 7% of cement whereas sand was replaced with bottom ash. Bricks were tested for compressive strength, modulus of rupture, ultrasonic pulse velocity (UPV), water absorption and durability. The results showed mix proportions of bottom ash, fly ash and cement as 1:1:0.15 i.e., M-15 achieved optimum values. The coal ash bricks were well bonded with mortar and could be feasible alternative to conventional bricks thus can contribute towards sustainable development.

Prediction of UCS and STS of Kaolin clay stabilized with supplementary cementitious material using ANN and MLR

  • Kumar, Arvind;Rupali, S.
    • Advances in Computational Design
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    • v.5 no.2
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    • pp.195-207
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    • 2020
  • The present study focuses on the application of artificial neural network (ANN) and Multiple linear Regression (MLR) analysis for developing a model to predict the unconfined compressive strength (UCS) and split tensile strength (STS) of the fiber reinforced clay stabilized with grass ash, fly ash and lime. Unconfined compressive strength and Split tensile strength are the nonlinear functions and becomes difficult for developing a predicting model. Artificial neural networks are the efficient tools for predicting models possessing non linearity and are used in the present study along with regression analysis for predicting both UCS and STS. The data required for the model was obtained by systematic experiments performed on only Kaolin clay, clay mixed with varying percentages of fly ash, grass ash, polypropylene fibers and lime as between 10-20%, 1-4%, 0-1.5% and 0-8% respectively. Further, the optimum values of the various stabilizing materials were determined from the experiments. The effect of stabilization is observed by performing compaction tests, split tensile tests and unconfined compression tests. ANN models are trained using the inputs and targets obtained from the experiments. Performance of ANN and Regression analysis is checked with statistical error of correlation coefficient (R) and both the methods predict the UCS and STS values quite well; but it is observed that ANN can predict both the values of UCS as well as STS simultaneously whereas MLR predicts the values separately. It is also observed that only STS values can be predicted efficiently by MLR.

A Study on Strength of Cement Mortar with Micro Grinding High Volume Fly-Ash (플라이애쉬를 다량 사용한 시멘트 경화체의 강도증진에 관한 실험적연구)

  • 정재동
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2001.11a
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    • pp.82-87
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    • 2001
  • The purpose of this study is for the active use of the fly ash, which is a by-product of the combustion pulverizes coal thermal power plants, to compensate for the lack of landfill and for conservation of energy, by using fly ash as the supplementary cementitious material, and to prove its possibility as the related products of the cement. First of all, the ordinary fly ash is grinded in a special method and its fineness is controlled from 6000$\textrm{cm}^2$/g to 8000$\textrm{cm}^2$/g, then replaced it with the 10% to 80% of the cement mortar in order to test physics characteristics. The first experiment conducts on the strength development in fly ash replacing content and fineness. and the changes of the flow values, incorporating fly ash into cement. The second one is about the slow development of the strength of the fly ash mortar in early ages, and improves its strength with the activator $Na_{2}SO_{4}$, using high volume fly ash.

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A Factor of Fly Ash on Fluidity of Fly Ash Cement Paste (플라이 애시 시멘트 페이스트의 유동성에 미치는 플라이 애시의 인자)

  • 이승헌;김홍주
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.153-158
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    • 2000
  • This study was carried out in order to investigate the relationship roundness of fly ashes and fluidity of fly ash cement paste. electrostatic precipitator system in coal-fired power plant have many successive collection fields in the direction of flue gas travel. In experiment, the roundness of fly ashes collected from the same location had similar values regardless of the load or boiler, and they increased going from the 1st collection filed to third collection filed in the direction of gas movement. In considering the relation between roundness of fly ashes and fluidity of fly ash cement paste, it has a high correlation.

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