The composition of the evolved gases from the thermal decomposition of certain metal sulfates

Collins, L.W.; Gibson, E. K.; Wendlandt, W.W.

doi:10.1016/0040-6031(74)85090-2

Cited by 12 publications

(9 citation statements)

References 6 publications

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“…Hence, since the oxygen exchange process must involve both decomposition and formation of sulfur-oxygen bonds, we believe that the oxygen isotope exchange takes place already between 160 and 250 °C. Traces of some sulfur oxide evolution at 250 °C was observed in earlier works 12 and is also detected by the present TPD study. At high magnifications, an additional SO 2 peak was clearly observed between 250 and 400 °C.…”

Section: Resultssupporting

confidence: 90%

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO₄·5H₂O

Danon¹,

Saig²,

Finkelstein³

et al. 2005

J. Phys. Chem. B

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Temperature-programmed desorption mass spectrometry (TPD-MS) measurements on [(18)O]water-enriched copper sulfate pentahydrate (CuSO(4).5H(2)(18)O) reveal an unambiguous occurrence of efficient oxygen isotope exchange between the water of crystallization and the sulfate in its CuSO(4) solid phase. To the best of our knowledge, the occurrence of such an exchange was never observed in a solid phase. The exchange process was observed during the stepwise dehydration (50-300 degrees C) of the compound. Specifically, the exchange promptly occurs somewhere between 160 and 250 degrees C; however, the exact temperature could not be resolved conclusively. It is shown that only the fifth, sulfate-associated, anionic H(2)O molecule participates in the exchange process and that the exchange seems to occur in a preferable fashion with, at the most, one oxygen atom in SO(4). Such an exchange, occurring below 250 degrees C, questions the common conviction of unfeasible oxygen exchange under geothermic conditions. This new oxygen exchange phenomenon is not exclusive to copper sulfate but is unambiguously observed also in other sulfate- and nitrate-containing minerals.

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Section: Resultssupporting

confidence: 90%

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO₄·5H₂O

Danon¹,

Saig²,

Finkelstein³

et al. 2005

J. Phys. Chem. B

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“…Using thermogravimetric/mass‐spectrometric results, Collins et al. () showed that thermal dissociation of the sulfate ion at high temperatures produces both SO 3 and SO 2 species. These gaseous species generated transiently by the decomposition reactions are resorbed into the melt‐system during postshock processing leading to no gas loss.…”

Section: Resultsmentioning

confidence: 99%

“…In this process, sulfates could decompose into sulfites (Collins et al. ) and further reduce to sulfides by “isentropic cooling” (Melosh and Artemieva ; Sheffer and Melosh ; Sheffer ).…”

Section: Introductionmentioning

confidence: 99%

Signatures of the Martian regolith components entrained in some impact‐melt glasses in shergottites

Rao

Nyquist

Ross

et al. 2018

Meteorit & Planetary Scien

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Martian regolith components are found in some impact melts (IM) containing Martian atmospheric gases in the shergottites Elephant Moraine (EET) 79001, Tissint, Zagami, and Shergotty. Excess sulfur abundances provide strong indicators for the presence of an exogenous component. High sulfur abundances and the SO3‐SiO2 correlation in polished thin section (PTS) EET 79001,507 (here #507) are comparable to those in Martian soils. Correlations of SO3 with FeO in #507 from Lithology B and of CaO and Al2O3 in EET 79001,506 (here #506) from Lithology A suggest the possible occurrence of two varieties of sulfate‐bearing phases in impact‐melt precursors. Fe/S (atomic) ratios of 1.02–1.34 determined in several sulfide blebs in #507 differ from those determined in igneous sulfides (Fe/S = 0.92), and suggest that most sulfide blebs in #507 are not related to igneous sulfides. Fe/S (atomic) ratios in a Tissint glass range from ~0.5 (pyrite) to >1.1 suggesting a mixture of sulfur‐bearing phases. S K‐XANES spectra of the blebs in EET 79001 and Tissint glasses show that sulfur occurs as mixed amorphous sulfide and sulfite. The δ34S values and the 87Sr/86Sr (I) ratios determined in EET 79001 impact melts are consistent with the proposition that the sulfide blebs result from decomposition of secondary sulfates into sulfites during shock heating followed by reduction to sulfides by isentropic cooling. These results suggest the presence in some shergottites of extraneous regolith components containing oxidized S‐bearing species resembling sulfur species present in Martian soils.

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“…Thermal decomposition reactions of the considered metal sulfates can be classified as in [36] where SO 2 and/or SO 3 gases are by-products. The decomposition temperatures or ranges for Al, Cu, Zn, Ni, Co, and Mn sulfates are summarized in Table 2, which is based on previous reports [33, [43][44][45][46]. Kolta and Askar [45] reported results from both their own study (upper row: TG/DTA) and from earlier literature (lower row).…”

Section: Thermal Decomposition Of Other Metal Sulfatesmentioning

confidence: 98%

Recycling of NdFeB Magnets Using Sulfation, Selective Roasting, and Water Leaching

Önal

Gerven

Guo

et al. 2015

J. Sustain. Metall.

116

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NdFeB magnets currently dominate the magnet market. Supply risks of certain rare earth metals (REMs), e.g., Nd and Dy, demand efficient recycling options that are applicable to different types and compositions with minimum use of chemicals and waste generation. In this study, a hydrometallurgical method is presented, which is adjustable to all NdFeB magnets, regardless of their composition. After completely transforming powdered samples into a sulfate mixture, a suitable selective roasting and water leaching treatment resulted in 95-100 % extraction efficiencies for Nd, Dy, Pr, Gd, Tb, and Eu, while Fe remained in the resultant residue forming a marketable hematitedominated by-product. Impurities other than Fe were also greatly separated from the leachate thereby enabling the production of a liquid with at least 98 % REM purity. Such a solution then can be directly treated with subsequent shortened downstream processes without pretreatments for impurity removal. Due to decomposition reactions of impurities, including Fe, during the selective roasting stage, the majority of consumed acid is recyclable resulting in an environment-friendly flow sheet.

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The composition of the evolved gases from the thermal decomposition of certain metal sulfates

Cited by 12 publications

References 6 publications

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO₄·5H₂O

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO₄·5H₂O

Signatures of the Martian regolith components entrained in some impact‐melt glasses in shergottites

Recycling of NdFeB Magnets Using Sulfation, Selective Roasting, and Water Leaching

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The composition of the evolved gases from the thermal decomposition of certain metal sulfates

Cited by 12 publications

References 6 publications

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO4·5H2O

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO4·5H2O

Signatures of the Martian regolith components entrained in some impact‐melt glasses in shergottites

Recycling of NdFeB Magnets Using Sulfation, Selective Roasting, and Water Leaching

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Product

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A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO₄·5H₂O

A New Route of Oxygen Isotope Exchange in the Solid Phase: Demonstration in CuSO₄·5H₂O