scholarly journals THERMAL DECOMPOSITION OF BARZAS COALS

2021 ◽  
Vol 64 (3) ◽  
pp. 92-99
Author(s):  
Ivan Ya. Petrov ◽  
Boris G. Tryasunov ◽  
Alexander R. Bogomolov ◽  
Konstantin Yu. Ushakov ◽  
Alexander S. Zyabrev
Keyword(s):  
Thermal Decomposition ◽  
Temperature Region ◽  
Adsorbed Water ◽  
Volatile Components ◽  
Coal Pyrolysis ◽  
Helium Atmosphere ◽  
Mineral Components ◽  
Temperature Programmed ◽  
Temperature Programmed Decomposition ◽  
Coal Organic Matter

Thermal decomposition processes of two types of Barzas sapromixites - a tile-like modification (“tile”) and a product of its weathering (“exfoliated tile”) - have been investigated in various media (air and helium). It has been shown that in the course of temperature-programmed decomposition (10 °C/min) of these forms of tile-like Barzas sapromixite, in both oxidizing (air) and inert (helium) atmospheres, four main temperature ranges can be distinguished: 1) < 150 °C - removal of adsorbed water (this temperature region is more pronounced for the weathered form of tile-like Barzas sapromixite); 2) 150-350 °C - removal of low molecular weight volatile components of coal in helium environment (with their simultaneous ignition in case of the decomposition in air); 3) 350-550 °C - the temperature region of primary or fast coal pyrolysis in an inert medium; in an oxidative medium, this stage of pyrolysis is accompanied by the burning of released tarry substances; 4) > 550 °C - the temperature region of secondary or high-temperature coal pyrolysis to form semi-coke in helium atmosphere, or the region of burning this semi-coke in air medium. Thermal breakdown processes of “exfoliated tiles” in the temperature range of the most intensive decomposition (350-550 °C) have been found to require less energy consumptions than the similar processes for tile-like Barzas coals (by 72-73 kJ/mol for both gas media of thermal treatment). It is supposed that the differences observed in thermal behavior of Barzas sapromixite forms under investigation may be related to the different contents of mineral components and their effects on the thermal decomposition of coal organic matter.

Temperature-programmed nitridation of monodispersed VOx nanoparticles into nanocrystalline superconducting oxygen-doped vanadium nitride

2021 ◽  
Author(s):  
Khemchand Dewangan ◽  
Dadan Singh ◽  
Sandeep Kumar Singh Patel ◽  
Kamlesh Kumar Shrivas
Keyword(s):  
Thermal Decomposition ◽  
Synthesis Process ◽  
Vanadium Nitride ◽  
High Quality ◽  
Two Stage ◽  
Stage Synthesis ◽  
Temperature Programmed ◽  
Superconducting Applications

A two-stage synthesis process was employed to prepare high-quality nanocrystalline vanadium nitride (VN) for superconducting applications. Firstly, monodispersed amorphous VOx nanoparticles were obtained via thermal-decomposition of vanadium (III) acetylacetonate [V(acac)3]...

scholarly journals Iron reduction from concentrates of hydrometallurgical dressing

2021 ◽  
Vol 64 (10) ◽  
pp. 728-735
Author(s):  
I. A. Rybenko ◽  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
M. A. Golodova ◽  
I. E. Khodosov
Keyword(s):  
Experimental Study ◽  
Thermal Decomposition ◽  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Solid Phase ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Reducing Agent ◽  
Volatile Components ◽  
Software Complex

The article presents results of theoretical and experimental studies of the processes of iron solid-phase reduction from an iron-containing concentrate obtained as a result of hydrometallurgical dressing of ferromanganese and polymetallic manganese-containing ores with coals of grades D (long-flame) and 2B (brown). The method of thermodynamic modeling using TERRA software complex was used to study the reducing properties of hydrocarbons by calculating equilibrium compositions in the temperature range of 373 - 1873 K. The authors obtained the dependences of compositions and volume of the gas phase formed as a result of the release of volatile components during heating on the temperature for the coals of the grades under consideration. As a result of thermodynamic modeling, the optimal temperatures and consumption are determined, which ensure the complete iron reduction from an iron-containing concentrate. The results of experimental studies were obtained by modern research methods using laboratory and analytical equipment, as well as methods of statistical processing. Results of the coals analysis carried out using the Setaram LabSys Evo thermal analyzer showed that the process of thermal decomposition of coals of the studied grades proceeds according to general laws. The process of thermal decomposition of long-flame coal proceeds less intensively than of brown coal. The results of an experimental study of the processes of thermal decomposition of reducing agents have shown that volumes of the gas phases, formed when coals are heated to a temperature of 1173 K in an argon atmosphere, practically coincide with the calculated values. As a result of thermodynamic modeling and experimental study, the optimal consumption of D and 2B grades of coal is determined at a temperature of 1473 K. The best reducing agent with a minimum specific consumption is long-flame coal of D grade. When determining the optimal amount of reducing agent in charge mixtures during the study of metallization processes, it was found that with an excess of reducing agent, it is possible to achieve almost complete extraction (98 - 99 %) of iron from the concentrate.

Temperature programmed decomposition of cobalt ethylene diamine complexes

1999 ◽  
Vol 334 (1-2) ◽  
pp. 141-148 ◽  
Author(s):  
S Dash ◽  
P.K Ajikumar ◽  
M Kamruddin ◽  
A.K Tyagi
Keyword(s):  
Ethylene Diamine ◽  
Temperature Programmed ◽  
Temperature Programmed Decomposition

A Study on Kinetics Parameters of Titanium Hydride Powder from Its TPD Spectrum for Metal Foam

2007 ◽  
Vol 534-536 ◽  
pp. 937-940 ◽  
Author(s):  
Dong Hui Yang ◽  
Sang Youl Kim ◽  
Bo Young Hur
Keyword(s):  
Titanium Hydride ◽  
Metal Foam ◽  
Al Alloy ◽  
Superposition Method ◽  
Kinetics Parameters ◽  
Foaming Process ◽  
Titanium Hydride Powder ◽  
Temperature Programmed ◽  
Set Up ◽  
Temperature Programmed Decomposition

In this paper, the whole temperature programmed decomposition (TPD) spectrum of titanium hydride was acquired by the special designed set-up. After separating and simulating the TPD spectrum by using Spectrum Superposition Method (SSM), Consulting Table Method (CTM) and differential spectrum technique, the kinetics parameters of titanium hydride and corresponding equations were obtained. Using these kinetics equations, the fabrication parameters of Al alloy foam can be determined and foaming process of Al alloy melt can be predicted.

scholarly journals Speciation of mercury in fly ashes by temperature programmed decomposition

2011 ◽  
Vol 92 (3) ◽  
pp. 707-711 ◽  
Author(s):  
M. Antonia Lopez-Anton ◽  
Ron Perry ◽  
Patricia Abad-Valle ◽  
Mercedes Díaz-Somoano ◽  
M. Rosa Martínez-Tarazona ◽  
...  
Keyword(s):  
Fly Ashes ◽  
Temperature Programmed ◽  
Temperature Programmed Decomposition

Thermal Analysis of Coal-Bearing Strata Kaolinite/potassium Acetate Intercalation Complex

2012 ◽  
Vol 538-541 ◽  
pp. 2077-2081
Author(s):  
Xiang Yao ◽  
Shuai Zhang ◽  
Bo Sun
Keyword(s):  
Thermal Decomposition ◽  
Potassium Acetate ◽  
Adsorbed Water ◽  
Infrared Emission ◽  
Sufficient Evidence ◽  
X Ray Diffraction ◽  
Intercalation Complex ◽  
X Ray ◽  
Basal Distance ◽  
Coordination Water

The thermal decomposition of coal-bearing strata kaolinite-potassium acetate(CK/KAc) intercalation complex has been studied using X-ray diffraction (XRD), thermogravimetry and differential thermogravimetric (TG-DTG) and infrared emission spectroscopy (IES). The XRD results show that the KAc has been successfully intercalated into coal-bearing strata kaolinite with an obvious basal distance increase of the first basal peak. The TG results show that the thermal decomposition of the intercalation complex occurs in four main steps (a) the loss of adsorbed water (b) the loss of coordination water (c) the loss of potassium acetate and (d) water through dehydroxylation. The IES of CK/KAc give the evidence on the changes of structure. These make all explanation have the sufficient evidence.

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