The Thermal Decomposition Behavior of Pyrite-Pyrrhotite Mixtures in Nitrogen Atmosphere

Abstract

To assess the thermal transformation process of common sulfide minerals in a nitrogen atmosphere, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and thermogravimetric mass spectrometry are employed to define the influence of the pyrrhotite content in pyrite-pyrrhotite mixtures (mixed minerals). The results indicate that an increase in pyrrhotite content decreases the temperature of the maximum mass loss rate of mixed minerals and reduces its mass loss. The solid-phase transformation of the thermal decomposition of mixed minerals is accelerated because the apparent activation energy of pyrrhotite is lower than that of pyrite and mixed minerals. However, the pyrrhotite makes the mixed minerals easier to sinter and agglomerate, which reduces the total volatilization amount of the gas product, S2; thus, the rate of mass loss decreases.

Operando exploration of tribochemical decomposition in synthetic FeS2 thin film and mineral iron pyrite

“…70 Ferrous and ferric sulfates can also form as minor products. Thermal decomposition of pyrite is described by the reaction (R2), 70,92 in which subscript "ad" stands for adsorbed states. Its activation energy is only 30 kJ mol −1 .…”

Effects of Pyrrhotite on the Combustion Behavior and the Kinetic Mechanism of Pyrite-Pyrrhotite Mixture Powders in the Air

“…Based on the previously discussed kinetic mechanism analysis and phase analysis results of combustion products, the combustion process of the pyrite-pyrrhotite mixture in the air was dominated by pyrite and accompanied by the surface heterogeneous combustion of pyrrhotite [53,54], as shown in Figure 7. Pyrrhotite particles were more easily adsorbed on the surface of pyrite particles during mixed mineral combustion due to their strong ability to absorb oxygen [44], which accelerated pyrite combustion.…”

Carbon-in-Silicate Nanohybrid Constructed by In Situ Confined Conversion of Organics in Rectorite for Complete Removal of Dye from Water

“…29-1495), muscovite (2θ values: 8.74° and 17.50°) [30], quartz (2θ values: 26.46° and 44.84°) [25], and pyrite (2θ values: 33.02°, 37.04°, 40.74°, 47.40°, and 56.28°) (JCPDS No. 71-0053) [33] appeared in the XRD patterns of MB-R, which indicate that small amounts of associated minerals coexist with the rectorite mineral. After MB-R was calcined at 600 °C under nitrogen atmosphere, the diffraction peak of rectorite at 2θ = 3.48° (0 0 1 plane) shifts to larger angle, which confirms that the layer spacing decreases, and the MB in the interlayer spacing of rectorite was converted to carbon [29,34].…”

“…The XRD patterns of MB-loaded rectorite and R/C and R/C-2HA4h adsorbents are shown in Figure 1. The characteristic reflections of rectorite (2θ values: 3.48 [33] appeared in the XRD patterns of MB-R, which indicate that small amounts of associated minerals coexist with the rectorite mineral. After MB-R was calcined at 600 • C under nitrogen atmosphere, the diffraction peak of rectorite at 2θ = 3.48 • (0 0 1 plane) shifts to larger angle, which confirms that the layer spacing decreases, and the MB in the interlayer spacing of rectorite was converted to carbon [29,34].…”