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Partially exchanged organophilic bentonites

Part I. characterization by thermal analysis on calcined mass basis

Journal of Thermal Analysis and Calorimetry
Authors: Jo Dweck, Emerson Paes Barreto, Sergio Meth, and Pedro Mauricio Büchler

this article, the mass fraction of organic cation present in the partially exchanged clays was quantified by a new method, which uses TG data on calcined mass basis. The results suggest the existence of an exchange limit characterized by the amount of

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Abstract  

When cement hydrated compositions are analyzed by usual initial mass basis TG curves to calculate mass losses, the higher is the amount of additive added or is the combined water content, the higher is the cement ‘dilution’ in the initial mass of the sample. In such cases, smaller mass changes in the different mass loss steps are obtained, due to the actual smaller content of cement in the initial mass compositions. To have a same mass basis of comparison, and to avoid erroneous results of initial components content there from, thermal analysis data and curves have to be transformed on cement calcined basis, i.e. on the basis of cement oxides mass present in the calcined samples or on the sample cement initial mass basis. The paper shows and discusses the fundamentals of these bases of calculation, with examples on free and combined water analysis, on calcium sulfate hydration during false cement set and on quantitative evaluation and comparison of pozzolanic materials activity.

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Early stages hydration of high initial strength Portland cement

Part I. thermogravimetric analysis on calcined mass basis

Journal of Thermal Analysis and Calorimetry
Authors: Alex Neves Junior, Romildo Dias Toledo Filho, Eduardo de Moraes Rego Fairbairn, and Jo Dweck

, first on calcined mass basis [ 12 ] by dividing all data by respective calcined mass: where M cb is mass% at a temperature T on calcined mass basis, M i is mass% at a temperature T on initial sample mass basis, and M c is mass% of calcined

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Abstract  

Residual oil sludges represent an environmental problem in the oil industry and need a proper destination in order to allow sustainable industrial processes when exploring natural resources. In the present paper, the influence of the water content on the oil sludge pyrolysis process was studied by thermal analysis. A method using thermogravimetry on calcined mass basis was developed to estimate the water content of oil sludges. The water present in the sludge vaporizes during the first thermal processing stage, interfering in the initial process of the organic components pyrolysis and increasing the total oil sludge pyrolysis enthalpy. By quantitative differential thermal analysis (DTA) it can be seen that the water content of the sludge may significantly affect the thermal balance of its industrial pyrolysis process.

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Journal of Thermal Analysis and Calorimetry
Authors: Marilda Vianna, Jo Dweck, Frank Quina, Flavio Carvalho, and Claudio Nascimento

Abstract  

Commercial bentonite (BFN) and organoclay (WS35), as well as iron oxide/clay composite (Mag_BFN) and iron/oxide organoclay composite (Mag_S35) were prepared for toluene and naphthalene sorption. Mag_BFN and Mag_S35 were obtained, respectively, by the precipitation of iron oxide hydrates onto sodium BFN and S35 clay particles. The materials were characterized by powder X-ray diffraction (XRD), X-ray Fluorescence (XRF), and TG and DTA. From XRF results and TG data on calcined mass basis, a quantitative method was developed to estimate the iron compound contents of the composites, as well as the organic matter content present in WS35 and Mag_S35.

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Journal of Thermal Analysis and Calorimetry
Authors: Armando Lucas Cherem da Cunha, Mariana Santos Lemos, Sergio Meth, Jardel Pereira Gonçalves, and Jo Dweck

. 15. Dweck , J , Cherem da Cunha , AL , Pinto , CA , Gonçalves , JP , Buchler , PM . Thermogravimetry on calcined mass basis—hydrated cement phases and pozzolanic activity quantitative analysis . J Therm Anal

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.06335.54 . 37. Dweck , J , Cherem da Cunha , AL , Pinto , CA , Gonçalves , JP , Büchler , PM . Thermogravimetry on calcined mass basis: hydrated cement phases and pozzolanic activity quantitative analysis . J Therm Anal

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