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Journal of Thermal Analysis and Calorimetry
Authors: T. Galkova, B. Pacewska, V. Samuskevich, J. Pysiak, and N. Shulga

Abstract  

The isothermal and non-isothermal transformations of polycrystalline CuNH4PO4⋅H2O in vacuum and in various gas atmospheres (in open air and in gaseous ammonia atmosphere) were studied at 20–800C by means of differential thermal analysis, thermogravimetry, X-ray diffraction, paper chromatography, optical microscopy and chemical analyses. The effects of the gas phase composition on the kinetic peculiarities of total gas evolution and on the partial processes of dehydration, ammonia removal and rearrangement of the anionic sub-lattice were considered.

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Abstract  

Attempt was made to evaluate the usefulness of thermoanalytical methods, combined with X-ray phase analysis and chemical analyses, for the study of thermal decomposition of waste materials to be subjected to thermal treatment. The object of the studies were petrochemical waste materials intended to be decomposed in a rotary furnace. Results are given of the studies of five selected waste materials.

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Abstract

The influence of spent catalyst from catalytic cracking in fluidized bed (FCC) on the hydration of two kinds of calcium aluminate cements (of about 40 and 70% content of alumina) was studied. Cement pastes were prepared with constant ratio of water/binder = 0.5 and with content of 0, 5 and 25% mass of addition as replacement of cement. The samples were stored at room temperature. Thermal analysis (TG, DTG), infrared absorption (FTIR) and X-ray diffraction methods were applied to investigate changes in various periods of hydration (up to 150 days). The compressive strength of cement mortars was also examined. On the basis of presented results it was affirmed that in studied conditions spent FCC catalyst is a reactive addition in calcium aluminate cement (CAC) pastes, which probably can create a new phase type C–A–S–H. It may be an interesting alternative for limitation of the negative phenomenon of conversion of aluminate hydrates, although the degree of the influence of the mineral additive depends on the composition of CAC and of the quantity of the used waste.

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Abstract  

The temperature range of phase transitions has been established for coal–tar pitches modified with various types of polymers. Mass loss rate was determined in relation to modifying polymer type. Simultaneous thermoanalytical method (DTA, DTG, TG), appeared to be very useful in studies on pitch-polymer compositions.

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