X-ray Diffraction as a Tool for Studying Stoichiometry and Kinetics of Solid State Thermal Decomposition Reactions. Application to the Thermal Decomposition of Bischofite MgCl2· 6H2O

1982 ◽  
Vol 22 (3) ◽  
pp. 207-213 ◽  
Author(s):  
F. H. Herbstein ◽  
M. Kapon ◽  
A. Weissman
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decomposition Reactions ◽  
Kinetics Of

scholarly journals Kinetics of the Thermal Decomposition of Rhodochrosite

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Iván A. Reyes ◽  
Mizraim Flores ◽  
Elia G. Palacios ◽  
Hernán Islas ◽  
Julio C. Juárez ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Mass Loss ◽  
Manganese Oxides ◽  
Absorption Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decomposition Reactions ◽  
Mass Losses ◽  
Rate Controlled ◽  
Kinetics Of

Manganese is a widely used element in the steel industry; its main source is a mineral named rhodochrosite (MnCO3). For industrial usage, rhodochrosite is reduced to different manganese oxides by means of nodulation furnaces. In this study, rhodochrosite was thermally analyzed at temperatures ranging from 100 °C to 1200 °C. XRD (Powder X-ray diffraction), XRF (X-ray fluorescence), AAS (Atomic Absorption Spectrometry), and FESEM-EDX (Field Emission Scanning Electron Microscopy-Energy Dispersive X-Ray Spectrometry) were used to characterize the mineral and the residues were analyzed by XRD and FTIR (Fourier-transform infrared spectroscopy) to determine the stoichiometry of the thermal decomposition reactions. Three mass losses were observed, the first attributed to the transformation from carbonate to manganese (III) oxide, the second to the reduction to manganese tetroxide, and the third to the decomposition of calcium carbonate (CaCO3) present as a contaminant in the studied mineral. Thermal decomposition kinetics shows that the first mass loss required 17.91 kJ mol−1, indicating a control by mass transport-controlled process. For the second and third mass loss, the apparent activation energy of 112.41 kJ mol−1 and 64.69 kJ mol−1 was obtained respectively, indicating that both mass loss events were rate-controlled.

Thermal Decomposition Kinetics of Ammonium Aluminum Carbonate Hydroxide

2008 ◽  
Vol 368-372 ◽  
pp. 1577-1579
Author(s):  
Hai Jun Zhang ◽  
En Xia Xiu ◽  
Xiu Juan Wang ◽  
Quan Li Jia ◽  
Hong Wei Sun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Preexponential Factor ◽  
Decomposition Kinetics ◽  
Algebraic Expression ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbonate Hydroxide ◽  
Kinetics Of ◽  
Scanning Electron

The thermal decomposition of ammonium aluminum carbonate hydroxide was studied under non-isothermal conditions in air. The decomposition kinetics were evaluated from data of TG-DTA by means of the Kissinger equation and the Coats-Redfern equation. The values of the activation energy E, the preexponential factor A and the algebraic expression of integral G(α) functions of the thermal decomposition were calculated. The ammonium aluminum carbonate hydroxide (AACH) was characterized by X-ray diffraction, differential thermal analysis and thermogravimetric and field emission scanning electron microscopy.

scholarly journals Preparation and thermal decomposition of solid state cinnamates of alkali earth metals, except beryllium and radium

1998 ◽  
Vol 23 (0) ◽  
pp. 91-98 ◽  
Author(s):  
Ana Glauce ZAINA CHIARETTO ◽  
Marco Aurélio da Silva CARVALHO FILHO ◽  
Nedja Suely FERNANDES ◽  
Massao IONASHIRO
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Solid State ◽  
General Formula ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Preparation And Thermal Decomposition ◽  
Derivative Thermogravimetry

Solid state compounds of general formula ML2.nH2O [where M is Mg, Ca, Sr or Ba; L is cinnamate (C6H5 -CH=CH-COO-) and n = 2, 4, 0.8, 3 respectively], have been synthetized. Thermogravimetry (TG), derivative thermogravimetry (DTG), differential scanning calorimetry (DSC) and X-ray diffraction powder patterns have been used to characterize and to study the thermal stability and thermal decomposition of these compounds.

scholarly journals Transition metal complexes with pyrazole based ligands, part 27: Structural and thermal characterization of cobalt(II) halide and pseudohalide complexes with 4-acetyl-3-amino-5-methylpyrazole

2007 ◽  
Vol 72 (12) ◽  
pp. 1281-1293 ◽  
Author(s):  
Vukadin Leovac ◽  
Zoran Tomic ◽  
Katalin Mészáros-Szécsényi ◽  
Ljiljana Jovanovic ◽  
Milan Joksovic
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Transition Metal Complexes ◽  
Thermal Characterization ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Vis Spectroscopy

The crystal and molecular structures of four tetrahedral structurally similar [Co(aamp)2X2] complexes (aamp = 4-acetyl-3-amino-5-methylpyrazole, X = Cl, Br, I and NCS) were determined by X-ray diffraction analysis and are discussed in detail. It was found that the different capacity of the ligand X (NCS vs. Cl, Br, I) for the formation of non-bonding contacts influence the mode of molecular association in the solid state. The complexes were characterized by UV-Vis spectroscopy. The first step of the thermal decomposition of the compounds was checked and is discussed in the view of the IR spectrum of the intermediate isolated from [Co(aamp)2Br2] by the quasi-isothermal technique.

Study of NH4EuF4 in solid state reaction Eu2O3–NH4F. Thermal analyses, calorimetry, and decomposition kinetics

1977 ◽  
Vol 55 (14) ◽  
pp. 2628-2630 ◽  
Author(s):  
Krishnan Rajeshwar ◽  
Etalo A. Secco
Keyword(s):  
Thermal Decomposition ◽  
Solid State ◽  
Solid State Reaction ◽  
Thermal Analyses ◽  
Decomposition Kinetics ◽  
X Ray ◽  
Kinetics Of Thermal Decomposition ◽  
Heat Of Decomposition ◽  
Kinetics Of

The solid state reaction Eu2O3–NH4F leading to the formation of NH4EuF4 was studied by thermal analyses and X-ray diffraction.The heat of decomposition of NH4EuF4 and the kinetics of thermal decomposition of NH4EuF4 are reported.

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