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2 edition of Thermal gravimetric analysis of pyrite oxidation at low temperature found in the catalog.

Thermal gravimetric analysis of pyrite oxidation at low temperature

J. E. Pahlman

Thermal gravimetric analysis of pyrite oxidation at low temperature

by J. E. Pahlman

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  • 2 Currently reading

Published by U.S. Dept. of the Interior, Bureau of Mines in Pittsburgh, Pa .
Written in English

    Subjects:
  • Mine fires.,
  • Pyrites.,
  • Oxidation-reduction reaction.

  • Edition Notes

    Bibliography: p. 12.

    Statementby J.E. Pahlman and G.W. Reimers.
    SeriesReport of investigations / United States Department of the Interior, Bureau of Mines;, 9059, Report of investigations (United States. Bureau of Mines) ;, 9059.
    ContributionsReimers, G. W.
    Classifications
    LC ClassificationsTN23 .U43 no. 9059, TN315 .U43 no. 9059
    The Physical Object
    Pagination12 p. :
    Number of Pages12
    ID Numbers
    Open LibraryOL2343231M
    LC Control Number86600243

    The thermal stability of Pt/Vulcan XC 72 catalysts and the PEM fuel cell catalyst layer is studied by thermal gravimetric analysis (TGA) in air. The products of decomposition are analyzed with TGA coupled with mass spectrometry (TGA−MS). Low temperature (− °C) carbon combustion in the presence of platinum is by: Thermal analysis In practice thermal analysis gives properties like; enthalpy, thermal capacity, mass changes and the coefficient of heat expansion. Solid state chemistry uses thermal analysis for studying reactions in the solid state, thermal degradation reactions, phase transitions and phase Size: KB.

    pyrite, 35% in sample with ½ pyrite and 0% in the sample dominated by greigite (Fig. 4b-d). 3. DISCUSSION In the studied pyrite, thermomagnetic behaviour is coherent with the DTA curve with the change due to the oxidation of pyrite observed at about °C (Fig. 1). Neverthe-File Size: KB. The mineral matter obtained from the low temperature ashing of several pyrite-containing coals from eastern Kentucky and southwestern Illinois are characterized by high temperature differential thermal analysis (DTA).}, doi = {}, journal = {}, number =, volume =, place = {United States}, year = {Sun Jan 01 EST }, month = {Sun Jan 01 EST }}.

      However, this temperature can vary due to the high surface area and various activity of the nanoparticles, which results in a more exothermic heat process during oxidation at low temperature. In general, it can be assumed that phase transformation in nano-granular systems occurs from to °C with different contribution from both oxides Cited by: creases with length of exposure showing that the pyrite-pyrhottite phase change progresses regardless of the effects of texture and shape. each of the specimens in order of increased length of exposure from The TGA (Thermal Gravimetric Analysis) is an apparatus for measuringmass as a.


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Thermal gravimetric analysis of pyrite oxidation at low temperature by J. E. Pahlman Download PDF EPUB FB2

Ducted fundamental thermal gravimetric analysis (TGA) research to deter­ mine the mechanisms and factors governing the rate of low-temperature pyrite oxidation, and to identify possible inhibitors to spontaneous oxidation and combustion. The mechanism of Cited by: 3.

Additional Physical Format: Online version: Pahlman, J.E. (John E.). Thermal gravimetric analysis of pyrite oxidation at low temperature. Pittsburgh, Pa.: U.S. Dept. The Bureau of Mines has conducted fundamental thermal gravimetric analysis (tga) research to determine the mechanisms and factors governing the rate of low- temperature pyrite oxidation, and to identify possible inhibitors to spontaneous oxidation and combustion.

Download PDF: Sorry, we are unable to provide the full text but you may find it at the following location(s): (external link) http. The temperature coefficient, or Q10, is widely used to describe the proportional change in rate, given a 10° change in temperature.

Q10 is reported to be between 2 and 3 for pyrite oxidation for temperatures between 3 and 25 °C (Nicholson et al., ). Q10 values at freezing temperatures are not by: If the limited solubility of pyrite and the low diffusivity of HS– are taken into account, only the pyrite within 2 cm of the canister surface will contribute to corrosion over a timescale, resulting in 1 µm of corrosion for the reference values of the solubility and diffusivity (SKB a).File Size: 1MB.

Thermogravimetric analysis (TGA) of polymers is conducted to measure weight changes as a function of temperature and time. The weight changes of polymeric materials can be caused by decomposition. MITOVSKI et al.: THERMAL ANALYSIS AND KINETICS OF THE CHALCOPYRITE-PYRITE CONCENTRATE mass increase on TG curve in the range - °C.

At the same time, chalcopyrite and bornite decompose into Cu 2 S, FeSO 4, Fe 3 O 4 and Fe 2 O 3, which is accompanied by a mass decrease on TG curve in the range - ° by: 3. Storage of specimens in low humidity and/or anoxic environments must follow afterward. Abstract. Pyrite (FeS. 2) is a common mineral found in sedimentary rock and fossils, and its decay is a major problem in the conservation of fossil specimens.

Pyrite oxidation, also referred to as pyrite disease or pyrite decay, is identified by a. PHOENICS. The pyrite oxidation rate is described by a shrinking-core model for spherical pyritic grains. Oxygen transport within the backfill material is assumed to be by diffusion.

A sensitivity analysis of the major parameters that influence the rate of the pyrite oxidation and subsequent pollutant generation has been carried out. The paper presents the results of experimental investigation of the chalcopyrite-pyrite concentrate oxidation in the air.

Characterisation of the initial sample and oxidation products was done by ICP-AES, XRD, EDXRF methods. Phase stability diagrams were constructed for Cu-Fe-S-O system at 25,and °C. The effect of heat and illumination with visible light on the oxidation of pyrite with dissolved molecular oxygen in solutions between pH 2 and 6 has been investigated using a combination of surface science experiments and batch oxidation experiments.

The rate of the oxidation of pyrite is strongly dependent on temperature. It is, however, not possible to cast the temperature Cited by: Experimental Study of Pyrite Oxidation at pH and 30°C by Martin B.

Goldhaber Abstract Experimental studies of pyrite oxidation over the pH range were carried out at 30°C in M KC1 under conditions of fixed pH and p Rate of addition of base necessary to maintain a fixed pH was monitored.

SamplesCited by: 4. The rate of pyrite oxidation is also greatly affected by the particle size of pyrite. Pyrite-oxidation rate increased drastically for particles less than 40 um. Room- temperature pyrophoric behavior was observed for freshly ground unoxidized pyrite (55 pct minus 5 um).

Pyrite, the most abundant metal sulfide at the surface of Earth, plays a key role in many processes such as acid mine drainage, redox cycling of metals at oxic-anoxic boundaries of lake bottom, and degradation of pollutants.

The oxidation of pyrite was studied in batch experiments over a large range of pH (−12), with trace oxygen. Surface analysis of the samples was. Thermal gravimetric analysis (TGA) of the MSCB polymers were performed on a Mettler TGA/SDTA thermal gravimetric analysis system at a heating rate of 20 ℃min −1 in air and nitrogen atmosphere from 30 ℃ to ℃.

X-ray photoelectron spectroscopy (XPS) of the sample surface was performed on a Thermo ESCALAB electron : Yunxing Pan, Shengli Cheng, Hang Dong, Nan Li, Feng Bao, Jinyan Wang, Xigao Jian. 1)Introduction to thermal analysis: Techniques and application, second edition, Springer, 2) Paul Gabbot, Principles and Applications of Thermal Analysis, Blackwell Publishing 3) Peter J.

Haines, Thermal methods of Analysis, Principles, Applications & Problems, Chapman and Hall 4) Wesley Wendlandt, Thermal Analysis, WileyFile Size: 2MB. Thermal gravimetric analysis and isothermal oxidation procedures were used to obtain information on pyrite ignition and the behavior of pyrite during low-temperature oxidation to ferrous sulfate.

The determination of treatment effectiveness was evaluated by adding 5 wt pct of the compound to the pyrite before milling. Thermal Analysis of Polymers • An example is oxidation induction time (OIT) by DSC which can determine the amount of oxidation stabiliser present in a thermoplastic (usually a polyolefin) polymer material.

• Compositional analysis is often made using TGA, which can separate fillers, polymer resin and other additives. In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits.

This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores.

A weight increment scaling method was used to measure Cited by: 3. 7. THERMOGRAVIMETRY Introduction: It is a method of thermal analysis in which a physical property of substance is measured as a function of temperature whilst the substance is subjected to a controlled temperature programmer.

An Internationally accepted definition of thermogravimetry is as follows: "It is a technique where by weight of.The present study aims to further understanding of the principal reactions that occur during coal oxidation at moderate temperatures.

Mass change and heat evolution of a sample were monitored by thermo-gravimetric analysis coupled with differential thermal analysis (TGA/DTA). Gaseous and solid products were traced using online or in situ Fourier trans- form Cited by: METTLER TOLEDO Selected Applications Thermal Analysis of Polymers 5 Preface Thermal analysis is one of the oldest analysis techniques.

Throughout history, people have used simple heat tests to determine whether materials were genuine or fake. The year is looked upon as the dawn of present-day thermal analysis.