Mössbauer spectroscopy study on the hydrothermal transformation α-FeOOH→α-Fe2O3

Barb, D.; Diamandescu, L.; Mihàilà-Tàràbàşanu, D.; Rusi, A.; Morariu, M.

doi:10.1007/bf02101054

Cited by 9 publications

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“…Many researchers studied the mechanism and kinetics of these complex reactions that can be classified into several groups according to the nature of the initial iron-bearing phase. Examples are as follows: the thermal decompositions of iron(III) compounds including FeO(OH), [7][8][9][10][11][12][13][14][15][16][17][18][19][20] Fe 2 (C 2 O 4 ) 3 , [21][22][23] Fe 2 (SO 4 ) 3 , [24][25][26] Fe(OH) 3 , 27 (NH 4 ) 2 Fe-(SO 4 ) 2 , 28 Fe(OH)SO 4 , [29][30][31][32] NaFe(SO 4 ) 2 , Na 3 Fe(SO 4 ) 3 , 33,34 FeCl 3 , 35,36 Fe(OH)CO 3 , 37 and NH 4 Fe(C 2 O 4 ) 2 ; 38 the thermally induced oxidation of metal iron, 39,40 Fe 3 O 4 , 41,42 and iron(II) compounds including FeCl 2 , 43 FeSO 4 , [43][44][45][46][47][48][49][50][51] FeS, 52,…”

Section: Thermal Transformations Of Iron-bearing Materialssclassifica...mentioning

confidence: 99%

“…Many researchers studied the mechanism and kinetics of these complex reactions that can be classified into several groups according to the nature of the initial iron-bearing phase. Examples are as follows: the thermal decompositions of iron(III) compounds including FeO(OH), − Fe 2 (C 2 O 4 ) 3 , − Fe 2 (SO 4 ) 3 , − Fe(OH) 3 , (NH 4 ) 2 Fe(SO 4 ) 2 , Fe(OH)SO 4 , − NaFe(SO 4 ) 2 , Na 3 Fe(SO 4 ) 3 , , FeCl 3 , , Fe(OH)CO 3 , and NH 4 Fe(C 2 O 4 ) 2 ; the thermally induced oxidation of metal iron, , Fe 3 O 4 , , and iron(II) compounds including FeCl 2 , FeSO 4 , − FeS, , FeC 2 O 4 , ,− and iron(II) malate; the thermally induced solid-state reaction of NaCl with Fe 2 (SO 4 ) 3 ; , the thermal transformations of iron complexes such as iron carbonyl systems, − iron carboxylate complexes, , and (NH 4 ) 3 [Fe(C 2 O 4 ) 3 ]; and the conversions of iron-bea...…”

Section: Thermal Transformations Of Iron-bearing Materialsclassifica...mentioning

confidence: 99%

“…The mechanism of Fe 2 O 3 formation from the iron precursor is very often different. For example, iron(III) oxide can be the product of the following: one-step transformation during thermal outgassing of Fe phases containing SO 3 , CO 2 , NH 3 , or H 2 O as in 2FeO(OH) → Fe 2 O 3 + H 2 O; − a multistage process during which different intermediate phases are formed, for instance, in the thermal transformation of FeSO 4 ·7H 2 O where FeSO 4 ·H 2 O, FeSO 4 , Fe(OH)SO 4 , Fe 2 (SO 4 ) 3 , and other intermediate phases are identified; − a process accompanied by a change in the iron valency, e.g., 2FeCl 2 + 3 / 2 O 2 → Fe 2 O 3 + 2Cl 2 ; and a process in which the iron(III) oxide is formed as one of the products of a solid-state reaction, for example, …”

Section: Thermal Transformations Of Iron-bearing Materialsclassifica...mentioning

confidence: 99%

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Iron(III) Oxides from Thermal ProcessesSynthesis, Structural and Magnetic Properties, Mössbauer Spectroscopy Characterization, and Applications

2002

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Structural and magnetic properties, methods of synthesis, and applications of seven iron-(III) oxide polymorphs, including rare beta, epsilon, amorphous, and high-pressure forms, are reviewed. Thermal transformations resulting in the formation of iron oxides are classified according to different parameters, and their mechanisms are discussed. 57 Fe Mo ¨ssbauer spectroscopy is presented as a powerful tool for the identification, distinction, and characterization of individual polymorphs. The advantages of Mo ¨ssbauer spectroscopy are demonstrated with two examples related to the study of the thermally induced solid-state reactions of Fe 2 (SO 4 ) 3 . Lead-InIron(III) oxide is not only a strategic industrial material but also a convenient compound for the general study of the polymorphism and the mutual polymorphous changes in nanoparticles. The existence of amorphous Fe 2 O 3 and four polymorphs (alpha, beta, gamma, and epsilon) has been established. Their discoveries as well as the majority of formation processes are connected with thermal transformations of iron-bearing materials in an oxidizing atmosphere. 57 Fe Mo ¨ssbauer spectroscopy is a unique method that allows one to distinguish and identify individual structural forms, amorphous and nanostructured Fe 2 O 3 particles, to analyze their magnetic properties and to study their formation mechanism during thermally induced solidstate reactions. In this review, thermal processes resulted in the Fe 2 O 3 formation are classified from different viewpoints and their mechanism is discussed. Applications, structural and magnetic properties, and methods of synthesis of all known forms of iron(III) oxide and their Mo ¨ssbauer characterization are also summarized. A detailed survey of the properties of rare forms (amorphous Fe 2 O 3 , β-Fe 2 O 3 , -Fe 2 O 3 , and highpressure Fe 2 O 3 ) is presented for the first time. With respect to the more known R-Fe 2 O 3 and γ-Fe 2 O 3 , the presented data spring from a series of previous works, including the excellent book by R. M. Cornell and U. Schwertmann. 1 Some unresolved problems, such as the relation between the properties of the original ferrogenous precursor and the structure of the formed iron-(III) oxide, or the experimental possibility to distinguish the amorphous Fe 2 O 3 from nanostructured γ-Fe 2 O 3 or R-Fe 2 O 3 particles are discussed. The value of Mo ¨ssbauer spectroscopy for the characterization of iron(III) oxides produced by thermal processes is demonstrated with two experimental examples taken from our work in the field. † Dedicated to R. L. Mo ¨ssbauer on the occasion of the 40 th jubilee of Nobel Prize presentation.

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Section: Thermal Transformations Of Iron-bearing Materialssclassifica...mentioning

confidence: 99%

“…Many researchers studied the mechanism and kinetics of these complex reactions that can be classified into several groups according to the nature of the initial iron-bearing phase. Examples are as follows: the thermal decompositions of iron(III) compounds including FeO(OH), − Fe 2 (C 2 O 4 ) 3 , − Fe 2 (SO 4 ) 3 , − Fe(OH) 3 , (NH 4 ) 2 Fe(SO 4 ) 2 , Fe(OH)SO 4 , − NaFe(SO 4 ) 2 , Na 3 Fe(SO 4 ) 3 , , FeCl 3 , , Fe(OH)CO 3 , and NH 4 Fe(C 2 O 4 ) 2 ; the thermally induced oxidation of metal iron, , Fe 3 O 4 , , and iron(II) compounds including FeCl 2 , FeSO 4 , − FeS, , FeC 2 O 4 , ,− and iron(II) malate; the thermally induced solid-state reaction of NaCl with Fe 2 (SO 4 ) 3 ; , the thermal transformations of iron complexes such as iron carbonyl systems, − iron carboxylate complexes, , and (NH 4 ) 3 [Fe(C 2 O 4 ) 3 ]; and the conversions of iron-bea...…”

Section: Thermal Transformations Of Iron-bearing Materialsclassifica...mentioning

confidence: 99%

Section: Thermal Transformations Of Iron-bearing Materialsclassifica...mentioning

confidence: 99%

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Iron(III) Oxides from Thermal ProcessesSynthesis, Structural and Magnetic Properties, Mössbauer Spectroscopy Characterization, and Applications

2002

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“…Majority of works addressed the hydrothermal method as its application in the synthesis of hematite. It was shown that the transition temperature of goethite (¸-FeO(OH)) into hematite (¸-Fe 2 O 3 ) is about 200 • C (Barb et al, 1990;Benhammada et al, 2020). It was also proven that the conditions of the process, such as pH, temperature, type of precipitating agent, clearly affected the morphology and physicochemical properties of the particles (Benhammada et al, 2020;Tadic et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

A study of the influence of synthesis parameters on the physicochemical properties of iron pigments produced from waste iron sulfate

Splinter,

Lendzion-Bieluńb

2023

Chemical and Process Engineering: New Frontiers

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The work presents a two-step method of iron red synthesis based on waste iron(II) sulfate. The synthesis was carried out using purified waste iron sulfate from titanium dioxide production. The study investigated the influence of factors such as temperature, pressure, concentration of solutions and synthesis time on the physicochemical properties of pigments. Obtained pigments were tested with instrumental analytical methods, e.g. X-ray Diffraction or BET surface area analysis. The pigments were analyzed for color, particle size as well as for oil number. The results of the research showed a change in the physicochemical properties of the obtained pigments depending on the conditions of synthesis. It was shown that increasing the synthesis time in most cases increased the degree of crystallization of hematite in the pigments. High specific surface area, low agglomeration of pigments or low oil absorption were directly related to the crystallinity of the pigments obtained. Laboratory pigments have been found to be different from commercial pigments. The difference in properties speaks in favor of synthesized materials.

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