La funcionalidad de los óxidos de hierro

Castaño, Juan G.; Arroyave, Carlos M.

doi:10.3989/revmetalm.1998.v34.i3.794

Cited by 7 publications

(6 citation statements)

References 26 publications

(27 reference statements)

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“…The oil absorption values for two replicas of obtained pigment (ABP325) were 15.36 and 16.34 g/100 g of pigment, respectively. These values are consistent with the oil absorption range for hematite pigments (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) and are highly dependent on the large particle size (14.57 μm) of ABP325 and even on the nature of the obtained product [29][30]. Oil absorption values generally depend on the pigment production method [11], since they get bigger with increasing density [31] or decreasing particle size [32].…”

Section: Characterization Of the Obtained Hematite Pigment (Abp 325)supporting

confidence: 87%

“…The average color parameters values in the CIELAB coordinates for the RP dispersed in coconut oil were as follows: L*=15.00, a*=2.09 and b*=5. 18. These results can be compared with the CIELAB coordinates (L*= 46.02, a*=-0.19 and b*=0.07) obtained for the steel scrap powder used by Della et al [16].…”

Section: Characterization Of the Hematite Pigment Precursor Residuementioning

confidence: 94%

“…The existing structural relationships between the main oxides and oxyhydroxides of iron generated as products of the carbon steel corrosion may be capable of producing hematite pigments by calcination, since this is one of the most thermodynamically stable phases and the final product of many oxidation transformation processes [17], as is summarized in Figure 1. Hematite, which can vary in color from light red to dark violet depending on its particle size, is widely used as a pigment in paints, varnishes, cosmetics , rubber, paper, glass, ceramics and tiles [18][19]. In this research, we sought to use a steelmaking residue from corrugated steel rods to obtain a hematite pigment by direct heat treatment.…”

Section: Introductionmentioning

confidence: 99%

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Obtaining a hematite pigment by thermal transformation of the surface oxide of reinforcing steel bars

Colpas-Ruiz¹,

Gnecco-Molina²,

Pérez³

et al. 2020

revuin

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En esta investigación,se reporta la valorización de la cascarilla de óxido superficial de varillas de acero al carbono mediante su transformación térmica en un pigmento compuesto principalmente por hematita (ɑ-Fe2O3). Se utilizó la Fluorescencia de Rayos X (XRF) yla Difracción deRayos X (XRD) para determinar el contenido elemental del residuo procesado e identificar los óxidos de hierro involucrados en la calcinación, respectivamente. El residuo siderúrgico en polvo se compone mayoritariamente por Fe2O3(87.92 %), SiO2 (6.13%),CaO (1.88 %), Al2O3(1.30 %) y MnO (0.77 %). El contenido total de hierro tiene principalmente el siguiente contenido en óxidos de hierro: magnetita, maghemita, wustita, lepidocrocita, hematita y goetita. El tratamiento térmico del residuo a temperaturas de 750-850 °C y tiempos de sostenimiento de 0.5-1.50 h, evidenció una alta conversión de los óxidos de hierro precursores en hematita, con porcentajes de esta fase que oscilan entre 86.4 y 94.6 %. La mayor obtención de hematita se logró a una condiciónde 850 °C y 1.00 h.

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Section: Characterization Of the Obtained Hematite Pigment (Abp 325)supporting

confidence: 87%

Section: Characterization Of the Hematite Pigment Precursor Residuementioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Obtaining a hematite pigment by thermal transformation of the surface oxide of reinforcing steel bars

Colpas-Ruiz¹,

Gnecco-Molina²,

Pérez³

et al. 2020

revuin

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“…Contemporary efforts in chemistry and physics proved iron oxides in its various phases as an interesting and important class of materials. The current and prospective fields include chemical industry, biotechnology, medicine, electromagnetic devices, − and magnetoelectronics . The properties of these materials are extensively dependent on the shape, size, and structures, leading to a growing interest in the nanoscale science, meaning thereby science, engineering, and technology concerned with the manipulation of the matter on the nanometer length scale.…”

Section: Introductionmentioning

confidence: 99%

Sonochemical Synthesis of Mesoporous Iron Oxide and Accounts of Its Magnetic and Catalytic Properties

et al. 2002

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Synthesis of mesoporous iron oxides has been reported using a sonochemical technique. Iron(III) ethoxide was used as an inorganic precursor and CTAB as an organic structure directing agent. After sonication the surfactant was removed by calcination and solvent extraction methods. FTIR spectra demonstrated the removal of the surfactant from the pores of the mesoporous iron oxide. The calcinated material was characterized by XRD, TEM, TGA, and BET surface area measurements. The surface area after solvent extraction is found to be 274 m2/g. The magnetic and catalytic properties of the materials have been studied. The as-prepared amorphous Fe2O3 has shown a paramagnetic behavior, while after calcination at 350 °C it changes to γ-Fe2O3 with good magnetic properties. The catalytic activity of mesoporous iron oxide was studied in the reaction of cyclohexane oxidation under mild conditions. The mesoporous Fe2O3 catalyst has shown high conversion of cyclohexane into cyclohexanone and cyclohexanol, with a high selectivity.

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“…Además, las elevadas temperaturas favorecen el endurecimiento por sedimen-tación de los compuestos férricos (Llorente, 2002). A estos compuestos se les atribuye un comportamiento adsorbente (Castaño y Arroyave, 1998), para amplias cantidades de metales traza y fosfatos; esta adsorción está influenciada por la presencia de diferentes formas de hierro en cantidades variables, por el pH, materia orgánica, entre otras propiedades del suelo (Acevedo, Ortiz, Cruz-Sánchez y Cruz-Chávez, 2004). Los compuestos férricos, en especial los oxidados son anfóteros, con respecto a la reacción con los iones H+ y OH-, y a valores de pH ácido promueven el incremento de la carga positiva (Prato, et al, 2013), sumado a la elevada superficie específica incrementan la adsorción de aniones como fosfatos, silicatos y ciertos metales (Acevedo, et al, 2004).…”

Section: Introductionunclassified

Uso de suelos calcinados para minimizar la eutrofización mediante adsorción de fosfatos en Chone, Ecuador

Orejuela

Huera

Carrera-Villacrés

2018

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ResumenLos fosfatos presentes en la Presa Multipropósito Chone han ocasionado problemas de eutrofización en la cuenca del río Grande que provoca afectaciones del tipo social, ambiental y económico para la zona. Una solución es el uso de tecnosoles que son suelos propios de lugar a los cuales se les adiciona elementos ajenos para mejorar su capacidad de remoción de un contaminante específico, sin embargo, este estudio se basó únicamente en la modificación del suelo de Chone mediante su calcinación y así simular un tecnosol capaz de remover fosfatos en soluciones acuosas mediante su calcinación, proceso que provoca un cambio en las propiedades físicas y químicas al tiempo de volatilizar los compuestos orgánicos presentes. Para esto, se realizó una disolución con concentración de 1.25 mg/L de fosfato monobásico de potasio, semejante a la concentración presente en el río. Las concentraciones del adsorbato contenidas en el agua ya filtrada a través del suelo modificado fueron medidas con espectrofotómetro en 4 sesiones continuas a intervalos de 2 horas, la máxima adsorción fue del 92% al cabo de 7 horas de filtrado; la cinética de la adsorción estuvo dada por una reacción de primer orden, además, se obtuvo un mejor ajuste con la isoterma de Langmuir que representó una adsorción en monocapa de fosfatos. Se modeló el comportamiento de la adsorción del fosfato en software libre con el que se estimó un tiempo de saturación del adsorbente de 14 horas. Como conclusiones del trabajo se tiene que los valores de adsorción de fosfatos son mayores con el suelo modificado (92%) que con el suelo natural (40.05%); la calcinación del suelo proporcionó una reactividad de los compuestos férricos presentes en el adsorbente con un incremento de su área superficial, intercambio catiónico y por ende una mayor adsorción del contaminante. AbstractThe phosphates present in the Presa Multipropósito Chone have caused eutrophication problems in the Rio Grande basin, causing social, environmental and economic impacts for the area. One solution is the use of technosols, which are soil added with foreign elements to improve their ability to remove a specific contaminant. However, this study was based on the modification of the Chone soil and thus simulated a technosol able of removing phosphates in aqueous solutions through its calcination, process that causes a change in the physical and chemical properties at the time of volatilizing the organic compounds present. For this, a solution with concentration of 1.25 mg/L of potassium phosphate monobasic was done, similar to the concentration present in the river. The concentrations of the adsorbate contained in the water already filtered through the modified soil were measured with a spectrophotometer in 4 continuous sessions at intervals of 2 hours, the maximum adsorption was 92% after 7 hours of filtering; the kinetics of the adsorption was given by a first-order reaction, in addition, a better fit was obtained with the Langmuir isotherm, which represented an adsorption in monolayer of phosphates. ...

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La funcionalidad de los óxidos de hierro

Cited by 7 publications

References 26 publications

Obtaining a hematite pigment by thermal transformation of the surface oxide of reinforcing steel bars

Obtaining a hematite pigment by thermal transformation of the surface oxide of reinforcing steel bars

Sonochemical Synthesis of Mesoporous Iron Oxide and Accounts of Its Magnetic and Catalytic Properties

Uso de suelos calcinados para minimizar la eutrofización mediante adsorción de fosfatos en Chone, Ecuador

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