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Abstract  

Reversed TALSPEAK (RT) Solvent [0.3 M di-(2-ethyl hexyl) phosphoric acid or D2EPHA in 0.2 M TBP in normal paraffinic diluent] is used as extractant in partitioning of lanthanides and actinides in post-UREX process flow sheets. There is no experimental data available in literature describing pressurization either due to the thermal decomposition or the reaction of RT solvent with nitric acid at elevated temperatures. Experiments were conducted for heating of RT solvent and acid equilibrated RT solvent under closed-vent adiabatic conditions. During these experiments, considerable pressurization was observed. In this paper, results of these experiments are discussed in detail.

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Abstract  

The thermal decompositions of dehydrated or anhydrous bivalent transition metal (Mn, Fe, Co, Ni, Cu, Zn, Cd) and alkali rare metal (Mg, Ca, Sr, Ba) methanesulfonates were studied by TG/DTG, IR and XRD techniques in dynamic Air at 250–850 °C. The initial decomposition temperatures were calculated from TG curves for each compound, which show the onsets of mass loss of methanesulfonates were above 400 °C. For transition metal methanesulfonates, the pyrolysis products at 850 °C were metal oxides. For alkali rare metal methanesulfonates, the pyrolysis products at 850 °C of Sr and Ba methanesulfonates were sulphates, while those of Mg and Ca methanesulfonate were mixtures of sulphate and oxide.

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nanocrystalline MgFe 2 O 4 via solid-state reaction at low heat [ 17 ] and to study magnetic properties of MgFe 2 O 4 and the kinetics of the thermal decomposition of precursor. The kinetics of the thermal decomposition of precursor was studied using TG

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Abstract  

The kinetics of individual stages of thermal decomposition of Al2(SO4)3·18H2O were studied by TG method. It is found that Al2(SO4)3·18H2O decomposes to Al2O3 in four major stages, all of endothermic. Some of these major stages are formed by sub-stages. The first three major stages are dehydration reactions in which two, ten and six moles water are lost, respectively. The last major stage is sulfate decomposition. In this study the kinetic parameter values of these major and sub-stages were calculated by integral and differential methods. The alterations of activation energies with respect to the decomposition ratio and to the method were investigated.

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. The polymer plays the role of binder in ceramic green body that is why it must be removed from the element to achieve fully densified, polycrystalline ceramic body [ 18 ]. The polymer is removed by its thermal decomposition during debinding process

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. proposed the synthesis of high surface area perovskites AFeO 3−δ (A is alkaline earth metal) by thermal decomposition of alkaline earth nitroprussides (A[Fe(CN) 5 NO]·nH 2 O) at low temperature, with a high content of Fe(IV) [ 35 , 36 ]. Some

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]. Similar to the clay minerals [ 29 , 30 ], thermal decomposition of asbestos minerals generally takes place according to three stages [ 7 , 31 ]. The first is associated with the loss of adsorbed water. The next step is connected to the removal of

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on the quality of the various constituent layers [ 13 , 14 ] and optimisation of the processing parameters relies thus on a sound understanding and control of the thermal decomposition process of the precursor solutions. A detailed

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pre-exponential factor of thermal decomposition reaction of MnV 2 O 6 ·4H 2 O can be obtained. (1) where β is the heating rate (K min −1 ); T P is the peak temperature of DSC curve (K); E a is the activation energy (kJ mol −1 ) of thermal

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Abstract  

Hydroxyurea and its derivatives are important nonsalt forming reductants in partitioning of uranium and plutonium in the nuclear fuel reprocessing operations. There is no experimental data available in open literature describing pressurization due to the thermal decomposition of aqueous and nitric solutions of hydroxyurea at elevated temperatures. Authors studied thermal decomposition of hydroxyurea-nitric acid system and resultant pressurization at various concentrations of nitric acid in an adiabatic calorimeter in closed-vent conditions. During these experiments, pressurization was observed. In this paper, results of these experiments have been discussed.

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