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Wen Wang - One of the best experts on this subject based on the ideXlab platform.

  • Compatibility of Ammonium Nitrate with Monomolecular Explosives. 2. Nitroarenes
    The Journal of Physical Chemistry, 1994
    Co-Authors: Jimmie C. Oxley, James L. Smith, Wen Wang
    Abstract:

    Ammonium Nitrate/fuel mixtures are widely used commercially; however, for military application it is often deemed necessary to enhance their performance by addition of conventional organic explosives. It is unreasonable to assume that such mixtures would retain the same thermal properties as the parent Ammonium Nitrate formulations. This paper presents a study of the thermal stability of such mixtures. Mixtures of Ammonium Nitrate and nitroaromatic compounds in various ratios have been decomposed isothermally in the temperature range 216-360 o C. The thermal decomposition kinetics of both Ammonium Nitrate and the nitroarenes have been followed by liquid chromatography. Markedly enhanced decomposition of both Ammonium Nitrate and the nitroarenes was observed

  • Compatibility of Ammonium Nitrate with Monomolecular Explosives. 1
    The Journal of Physical Chemistry, 1994
    Co-Authors: Jimmie C. Oxley, James L. Smith, Wen Wang
    Abstract:

    The thermal stability of mixtures of Ammonium Nitrate with a variety of organic explosives was examined over the temperature range 170 to 320 o C. Although the overall stability of the one-to-one mixtures was studied, the emphasis was comparison of the thermal stability (isothermal rate constants) of the individual components in the mixture with the neat species. It was found that Nitrate esters, PETN and nitrocellulose, nitramines, RDX and HMX, and nitroarenes, TNT and trinitroaniline, destabilized Ammonium Nitrate. In turn, Ammonium Nitrate, or its decomposition products, destabilized the organic explosives to varying degrees. For RDX and PETN the destabilization was slight

Jimmie C. Oxley - One of the best experts on this subject based on the ideXlab platform.

  • Compatibility of Ammonium Nitrate with Monomolecular Explosives. 2. Nitroarenes
    The Journal of Physical Chemistry, 1994
    Co-Authors: Jimmie C. Oxley, James L. Smith, Wen Wang
    Abstract:

    Ammonium Nitrate/fuel mixtures are widely used commercially; however, for military application it is often deemed necessary to enhance their performance by addition of conventional organic explosives. It is unreasonable to assume that such mixtures would retain the same thermal properties as the parent Ammonium Nitrate formulations. This paper presents a study of the thermal stability of such mixtures. Mixtures of Ammonium Nitrate and nitroaromatic compounds in various ratios have been decomposed isothermally in the temperature range 216-360 o C. The thermal decomposition kinetics of both Ammonium Nitrate and the nitroarenes have been followed by liquid chromatography. Markedly enhanced decomposition of both Ammonium Nitrate and the nitroarenes was observed

  • Compatibility of Ammonium Nitrate with Monomolecular Explosives. 1
    The Journal of Physical Chemistry, 1994
    Co-Authors: Jimmie C. Oxley, James L. Smith, Wen Wang
    Abstract:

    The thermal stability of mixtures of Ammonium Nitrate with a variety of organic explosives was examined over the temperature range 170 to 320 o C. Although the overall stability of the one-to-one mixtures was studied, the emphasis was comparison of the thermal stability (isothermal rate constants) of the individual components in the mixture with the neat species. It was found that Nitrate esters, PETN and nitrocellulose, nitramines, RDX and HMX, and nitroarenes, TNT and trinitroaniline, destabilized Ammonium Nitrate. In turn, Ammonium Nitrate, or its decomposition products, destabilized the organic explosives to varying degrees. For RDX and PETN the destabilization was slight

Wang Guang-long - One of the best experts on this subject based on the ideXlab platform.

  • Study on Thermal Stability of Ammonium Nitrate
    Journal of Zhengzhou University of Technology, 2003
    Co-Authors: Wang Guang-long
    Abstract:

    Mechanism and influence factors on thermal decomposition of Ammonium Nitrate between 100～150 ℃ are studiedEffect of stabilizing agents and activator is emphatically analyzedThe thermal stability of system is reduced by activators,such as moisture,nitric acid,sulfuric acid and phosphoric acidCompared with pure Ammonium Nitrate,when 05%(wt%) of the activator in the system,the induction time could be decreased by 50%Adding 3% of zinc oxide or aluminum hytroxide,the decomposition reaction might be effectively inhibitedBut for calcium carbonate or potassium chloride,to achieve the same effect needs 15%Urea is a suitable stabilizing agent of Ammonium NitrateDecomposition at 130 ℃ is stopped when there is 1% of urea in the system 

Dongke Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Thermal stability and kinetics of decomposition of Ammonium Nitrate in the presence of pyrite
    Journal of Hazardous Materials, 2009
    Co-Authors: Richard Gunawan, Dongke Zhang
    Abstract:

    The interaction between Ammonium Nitrate based industrial explosives and pyrite-rich minerals in mining operations can lead to the occurrence of spontaneous explosion of the explosives. In an effort to provide a scientific basis for safe applications of industrial explosives in reactive mining grounds containing pyrite, Ammonium Nitrate decomposition, with and without the presence of pyrite, was studied using a simultaneous Differential Scanning Calorimetry and Thermogravimetric Analyser (DSC-TGA) and a gas-sealed isothermal reactor, respectively. The activation energy and the pre-exponential factor of Ammonium Nitrate decomposition were determined to be 102.6 kJ mol(-1) and 4.55 x 10(7)s(-1) without the presence of pyrite and 101.8 kJ mol(-1) and 2.57 x 10(9)s(-1) with the presence of pyrite. The kinetics of Ammonium Nitrate decomposition was then used to calculate the critical temperatures for Ammonium Nitrate decomposition with and without the presence of pyrite, based on the Frank-Kamenetskii model of thermal explosion. It was shown that the presence of pyrite reduces the temperature for, and accelerates the rate of, decomposition of Ammonium Nitrate. It was further shown that pyrite can significantly reduce the critical temperature of Ammonium Nitrate decomposition, causing undesired premature detonation of the explosives. The critical temperature also decreases with increasing diameter of the blast holes charged with the explosive. The concept of using the critical temperature as indication of the thermal stability of the explosives to evaluate the risk of spontaneous explosion was verified in the gas-sealed isothermal reactor experiments.

  • A mechanistic study into the reactions of Ammonium Nitrate with pyrite
    Chemical Engineering Science, 2006
    Co-Authors: Richard Gunawan, Sawsan J. Freij, Dongke Zhang, Fiona Beach, Michael Littlefair
    Abstract:

    Abstract The reaction of Ammonium Nitrate with pyrite was studied using a simultaneous differential scanning calorimetry and thermogravimetric analyser (TGA/DSC). When a mixture of pyrite and Ammonium Nitrate is heated at a constant heating rate of 10 K min - 1 from room temperature to 800 ∘ C , two exothermic reactions occur at about 200 and 450 ∘ C , respectively. The first exothermic reaction is considered to take place between Ammonium Nitrate and pyrite where NO, NH 3 , SO 2 and N 2 O gases are produced. The second exothermic reaction is due to the oxidation of the remaining pyrite by atmospheric oxygen. Based on the quantitative analysis of the gaseous and solid products of the reaction, a new overall reaction is proposed at the first exothermic peak of interest, which is thermodynamically favourable. The results have significant implication in the understanding of stability of Ammonium Nitrate-based industrial explosives in reactive mining grounds containing pyritic minerals.

Richard Gunawan - One of the best experts on this subject based on the ideXlab platform.

  • Thermal stability and kinetics of decomposition of Ammonium Nitrate in the presence of pyrite
    Journal of Hazardous Materials, 2009
    Co-Authors: Richard Gunawan, Dongke Zhang
    Abstract:

    The interaction between Ammonium Nitrate based industrial explosives and pyrite-rich minerals in mining operations can lead to the occurrence of spontaneous explosion of the explosives. In an effort to provide a scientific basis for safe applications of industrial explosives in reactive mining grounds containing pyrite, Ammonium Nitrate decomposition, with and without the presence of pyrite, was studied using a simultaneous Differential Scanning Calorimetry and Thermogravimetric Analyser (DSC-TGA) and a gas-sealed isothermal reactor, respectively. The activation energy and the pre-exponential factor of Ammonium Nitrate decomposition were determined to be 102.6 kJ mol(-1) and 4.55 x 10(7)s(-1) without the presence of pyrite and 101.8 kJ mol(-1) and 2.57 x 10(9)s(-1) with the presence of pyrite. The kinetics of Ammonium Nitrate decomposition was then used to calculate the critical temperatures for Ammonium Nitrate decomposition with and without the presence of pyrite, based on the Frank-Kamenetskii model of thermal explosion. It was shown that the presence of pyrite reduces the temperature for, and accelerates the rate of, decomposition of Ammonium Nitrate. It was further shown that pyrite can significantly reduce the critical temperature of Ammonium Nitrate decomposition, causing undesired premature detonation of the explosives. The critical temperature also decreases with increasing diameter of the blast holes charged with the explosive. The concept of using the critical temperature as indication of the thermal stability of the explosives to evaluate the risk of spontaneous explosion was verified in the gas-sealed isothermal reactor experiments.

  • A mechanistic study into the reactions of Ammonium Nitrate with pyrite
    Chemical Engineering Science, 2006
    Co-Authors: Richard Gunawan, Sawsan J. Freij, Dongke Zhang, Fiona Beach, Michael Littlefair
    Abstract:

    Abstract The reaction of Ammonium Nitrate with pyrite was studied using a simultaneous differential scanning calorimetry and thermogravimetric analyser (TGA/DSC). When a mixture of pyrite and Ammonium Nitrate is heated at a constant heating rate of 10 K min - 1 from room temperature to 800 ∘ C , two exothermic reactions occur at about 200 and 450 ∘ C , respectively. The first exothermic reaction is considered to take place between Ammonium Nitrate and pyrite where NO, NH 3 , SO 2 and N 2 O gases are produced. The second exothermic reaction is due to the oxidation of the remaining pyrite by atmospheric oxygen. Based on the quantitative analysis of the gaseous and solid products of the reaction, a new overall reaction is proposed at the first exothermic peak of interest, which is thermodynamically favourable. The results have significant implication in the understanding of stability of Ammonium Nitrate-based industrial explosives in reactive mining grounds containing pyritic minerals.