Summary Red mud is insoluble, fine-grained waste residue which is generated as a by product during the production of alumina from the Bayer process. In this article, the thermal behavior of Aughinish red mud was investigated using thermal gravimetric analysis (TG) and differential thermal analysis (DTA). For identification of oxide and mineral phases in the red mud sample, XRD method, scanning electron microscopy (SEM), EDAX were used. Iron (30.4%), aluminium (23.6%) and titanium (17.85%) oxides are major oxides in the sample. Two endothermic peaks were shown on DTA curve. The total mass loss in the red mud was found to be 10.1%, which was associated with moisture and water molecules in gibbsite and boehmite phases.
Authors:T. Martins, J. Matos, G. Vicentini, and P. Isolani
Rare earth picrate complexes
with L-leucine (Leu) were synthesized and
characterized. Elemental analysis (CHN), EDTA titrations and thermogravimetric
data suggest a general formula RE(pic)32Leu⋅5H2O
(RE=La–Lu, Y and pic=picrate).
IR spectra indicate the presence of water and suggest that L-leucine is coordinated
to the central ion through the nitrogen of the aminogroup. The absorption
spectrum of the solid Nd compound indicates that the metal-ligand bonds show
a weak covalent character. Emission spectra and biexponential behavior of
the luminescence decay of the Eu compound suggest the existence of polymeric
species. Thermal analysis results indicate that all the compounds present
a similar behavior, with five major thermal decomposition steps. The final
products are rare earth oxides. A slow heating rate is necessary to observe
all decomposition steps.
Authors:E. Andogová, K. Györyová, and F. Nour El-Dien
Four new complex compounds were prepared by the reaction of zinc bromobutyrate and organic ligands. The general formula of the synthetized complex compounds are (2-Brbut)2ZnL and (4-Brbut)2ZnL2nH2O (but=butyrate, L=theobromine (tbr), theophylline (tph), methyl-3-pyridyl carbamate (mpc), n=0-1). The compounds were characterized by chemical analysis and IR spectroscopy. The thermal behaviour of the zinc(II) complexes was studied by thermal analysis. Thermal decomposition in the case of hydrated compounds starts with the release of water molecules. Then molecules of organic ligands and the bromobutyrate anion are released and decomposed. CH3CH2CH=O, CO, CH2=CHCH=O, CH2O and ZnBr2 were found as gaseous products of thermal decomposition during heating up to 700°C. IR, mass spectroscopy, X-ray powder diffraction and chemical analysis were used for the determination of solid and gaseous intermediates and products of the thermal decomposition.
have taken place occurring roughly within similar years such as was the foundation of two thermoanalytical periodicals, i.e., Journal of ThermalAnalysis and Calorimetry (JTA-1969, JTAC-1998) and Thermochimica Acta (TCA-1970) as well as the
The synthesis and characterization of lanthanide(III) citrates with stoichiometries 1:1 and 2:3; [LnL·xH2O] and [Ln2(LH)3·2H2O], Ln=La, Ce, Pr, Nd, Sm and Eu are reported. L stands for (C6O7H5)3− and LH for (C6O7H6)2−. Infrared absorption spectra of both series evidence coordination of carboxylate groups through symmetric bridges or chelation.
X-ray powder patterns show the amorphous character of [LnL·xH2O]. The compounds [Ln2LH3·2H2O] are crystalline and isomorphous. Emission spectra of Eu compounds suggest C2v symmetry for the coordination polyhedron of [LnL·xH2O] and C4v for [Ln2(LH)3·2H2O]. Thermal analyses (TG-DTG-DTA) were carried out for both series. The thermal analysis patterns of the two series are quite
different and both fit in a 4-step model of thermal decomposition, with lanthanide oxides as final products.
The reaction between SiO2 and MgO at temperatures up to 1500°C was studied using thermal analysis, with X-ray diffraction being used to identify reaction
products. The reaction is slow and results in the formation of Mg2SiO4 and MgSiO3, with minor amounts of SiO2·nH2O and residual amounts of unreacted SiO2 and MgO. Complete reaction of the starting materials to form Mg2SiO4 can only be achieved by maintaining the mixture at 1500°C for extended periods of time (>1 h).
Angra dos Reis/Itaguai region of the state of Rio de Janeiro, Brazil, is a very problematic area due to the instability of
slope and landslides, due to geological and geomorphological conditions and to the significant and continuous human occupation
over favorable areas is prone to the triggering of landslides. The samples were analyzed by thermogravimetry (TG), derivative
thermogravimetry (DTG) and differential thermal analysis (DTA). This paper analyzes and characterizes the clay minerals and
presence of water, gravitational mass movements’ sites and compares it with sites where gravitational mass movements do not
occur. Indeed, this analysis also attempts to verify the presence of minerals.
Authors:Ray Frost, Sara Palmer, János Kristóf, and Erzsébet Horváth
is important especially for the analysis of minerals on planets such as Mars. Thermalanalysis has been used extensively for testing the stability of minerals. To the best of the authors’ knowledge no thermoanalytical studies of halotrichites have
Authors:J. Orewczyk, S. Jasieńska, J. Pacyna, T. Skrzypek, and S. Iwanczenko
Application of thermal analysis to determine a quantity portion of iron oxides in symmetric blast furnace sinters is presented.
In the multicomponent sample, calcium ferrites and many silicate phases beside doped iron oxides phases were observed.
The dependence of sinter phase composition from basicity and relation with physicochemical properties is defined.
This research was aimed
to investigate the role of clay on the combustion and kinetic behavior of
crude oils in limestone matrix. For this purpose, simultaneous TG (thermogravimetry)
and DTA (differential thermal analysis) experiments were performed at three
different heating rates as 10–15 and 20C min–1,
respectively. A uniform trend of decreasing activation energies was observed
with the addition of clay. It was concluded that clays surface area affects
the values of Arrhenius constant, while it is the catalytic properties of
clay, which lower the activation energies of all the reactions, involved in
the combustion process.