Coprecipitation Of Barium Research Articles

A qualitative and quantitative investigation of partitioning and local structure of arsenate in barite lattice during coprecipitation of barium, sulfate, and arsenate

A qualitative and quantitative investigation of partitioning and local structure of arsenate in barite lattice during coprecipitation of barium, sulfate, and arsenate

Coprecipitation of barium and strontium nitrates in the course of crystallization from nitric acid solutions and simulated high-level PUREX process raffinate

The formation of solid solutions of barium and strontium nitrates in the course of precipitation from solutions of HNO3, La(NO3)3, and their mixtures was proved by X-ray diffraction, chemical analysis, and IR spectroscopy. Solid solutions of Ba(NO3)2 and Sr(NO3)2 in the system with water are formed from saturated solutions at 25°С and molar ratio Ba(NO3)2: Sr(NO3)2 < 10. True coprecipitation in a wide composition range in HNO3 solutions is observed when the total nitrate ion concentration (ΣNO 3 - ) reaches approximately 5 M and higher values. In La(NO3)3 solutions, the coprecipitation occurs at ΣNO 3 - ≥ 6.5 M. In the process, the Sr(NO3)2 concentration does not decrease below its solubility level. A solid solution is formed from aqueous solution at ΣNO 3 - < 5 M in the region of Sr(NO3)2 concentrations below its solubility level, which suggests different mechanisms of cocrystallization from neutral and acid solutions. A crystallographic study of the precipitate obtained from a mixture solution containing simultaneously barium and strontium nitrates against the background of 1 M La(NO3)3 and 2 M HNO3 showed that the crystals were covered with a noncrystalline shell, apparently, with a layer of adsorbed HNO3 released in the course of crystallization. The IR spectrum of such precipitate contains a band characteristic of molecular HNO3 in nonaqueous media, which probably suggests the formation of an adduct.

Co-precipitation of yttrium and barium fluorides from aqueous solutions

Co-precipitation of barium and yttrium fluorides from aqueous solutions at room temperature produced non-equilibrium Ba1−xYxF2+x nanofluoride phase with face-centered cubic crystal lattice of fluorite-type with the composition interval of the homogeneity for x=0.35–0.75. Lattice parameter a of this solid solution nanophase varied as a function of the sample chemical composition in a complex manner with two areas of linear dependency, from x=0.35 to 0.45 and from x=0.50 to 0.75. A plausible explanation of this phenomenon included a change of the type of crystal lattice defects and the manner of their population with the corresponding ions. An increase of the relative amount of yttrium in the HF reaction system led to the formation of hydroxonium salt of decafluorotriyttrium acid, (H3O+)Y3F10−·nH2O, instead of expected YF3 hydrate. No formation of oxyfluoride phases under acidic conditions has been observed.

Solubility and coprecipitation of barium and strontium nitrates in HNO3 solutions and multicomponent systems

The solubility of Ba(NO3)2 and Sr(NO3)2 in HNO3 solutions at 25–95°C is characterized by the power dependence on the total concentration of the nitrate ion with the exponent for Ba(NO3)2 equal to −2 in ∼9 M HNO3 and −6 in more concentrated acid solutions. The latter exponent is also characteristic of the more soluble Sr(NO3)2 throughout the examined range of HNO3 concentrations. In strongly acidic solutions, Ba(NO3)2 coprecipitates with Sr(NO3)2. The solubility curve for Ba(NO3)2 in NH4(Na)NO3 solutions suggests formation of a double salt, whereas in UO2(NO3)2 solutions the dependence is the same as in HNO3 solutions.

RETRACTED: Effect of Fe/Ba mole ratios and surface-active agents on the formation and magnetic properties of co-precipitated barium hexaferrite

Nanocrystalline barium hexaferrite (BaFe 12O 19) powders have been synthesized through the co-precipitation route. The produced ferrite precursors were obtained from aqueous mixtures of barium and ferric chlorides by co-precipitation of barium and iron ions using 5 M sodium hydroxide solution at pH 10 in room temperature. These precursors were calcined at temperatures of 800–1200 °C for constant 2 h in a static air atmosphere. The effect of Fe 3+/Ba 2+ mole ratio and addition of surface-active agents during co-precipitation step on the crystal structure, morphology and magnetic properties of produced ferrite powders were studied. The results obtained showed that the single phase BaFe 12O 19 powders was achieved by decreasing the Fe 3+/Ba 2+ molar ratio from the stoichiometric value 12 to 8 and increasing the calcination temperature ≥1000 °C. In addition, the Fe 3+/Ba 2+ mole ratio of 8 and presence of surface-active agents promoted the formation of homogeneous nanopowders (ca. 113 nm) of BaFe 12O 19 at a low temperature of 800 °C with good saturation magnetization (50.02 emu/g) and wide coercivities (642.4–4580 Oe).

Synthesis and characterization of barium hexaferrite nanoparticles

This investigation dealt with the synthesis of nanocrystalline barium hexaferrite (BaFe 12O 19) powders through the co-precipitation–calcination route. The ferrite precursors were obtained from aqueous mixtures of barium and ferric chlorides by co-precipitation of barium and iron ions using 5 M sodium hydroxide solution at pH 10 in room temperature. These precursors were calcined at temperatures of 800–1200 °C for constant 2 h in a static air atmosphere. The effect of Fe 3+/Ba 2+ mole ratio and addition of surface active agents during co-precipitation step on the structural and magnetic properties of produced ferrite powders were studied. It is found that the formation of single phase BaFe 12O 19 powders was achieved by decreasing the Fe 3+/Ba 2+ molar ratio from the stoichiometric value 12–8 and increasing the calcination temperature ≥1000 °C. In addition, the Fe 3+/Ba 2+ mole ratio of 8 the surface active agents promoted the formation of homogeneous nanopowders (ca. 113 nm) of BaFe 12O 19 at a low-temperature of 800 °C with resultant good magnetic saturations (50.02 emu/g) and wide intrinsic coercivities (642.4–4580 Oe).

X-Ray Powder Diffraction Data for BaCu(C2O4)2·6H2O

AbstractAn indexed powder diffraction pattern and related crystallographic data are reported for a new phase, BaCu(C2O4)2·6H2O, which was a major product in the coprecipitation of barium and copper oxalates.

Thermal Analysis of Precursors of Barium Titanate Prepared by Coprecipitation

Thermal analysis was performed on coprecipitated materials and on individual components. The detailed decomposition schemes of coprecipitates and individual components are proposed and discussed. According to the proposed decomposition schemes, the values of the observed weight loss are in good agreement with those of the theoretical values of the coprecipitated materials and individual components. The results indicate that barium titanyl oxalate is an inserting compound, i.e., a structure of distorted barium hydrogen oxalate hydrate being inserted by Ti(OH)3+. The results also verify that copreciptation of barium and titanium ions in an oxalate aqueous solution at pH 7 is a mixture of BaC2O4· 0.5H2O and TiO(OH)2· 1.5H2O and coprecipitation of barium and titanium ions using the process of Yamamura et al. is a mixture of Ba(NO3)2 and Ti(OH)2C2O4.

Coprecipitation of barium with lead sulfate

Coprecipitation of barium with lead sulfate

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Note on the coprecipitation of barium and lead selenates

Coprecipitation of barium and lead selenates was studied by conventional precipitation method. The precipitates were obtained by treating mixed solution of barium and lead nitrates having different composition, with ammonium selenate solution. Electron microscopy and X-ray diffraction methods were used to analyse the precipitates. The precipitated crystals formed do not exist as a mixture of two compounds but as a solid solution. The X-ray pattern of the precipitate having a composition of 80 BaSeO4:20 PbSeO4 clearly exhibits two solid phases co-existing, thus indicating it to be a mixture. The limit of dissolution of lead selenate in barium selenate, therefore, appears to be in between 90 BaSeO4:10 PbSeO4 and 80 BaSeO4:20 PbSeO4. The morphology of the particles is properly altered according to the compositions of precipitates. Barium selenate being less soluble than lead selenate, precipitated predominantly and a small quantity of lead selenate coprecipitated. The precipitated particles containing 90 BaSeO4:10 PbSeO4 have the same morphological and crystallographical properties as those of pure barium selenate. Similar is the case with 10 BaSeO4 :90 PbSeO4. As long as barium selenate can dissolve lead selenate, ideally in itself, the morphological characteristics of barium selenate remain unaltered. Similarly, lead selenate can dissolve barium selenate without losing its morphological characteristics. Further, the limitation of dissolution is smaller in the case of lead selenate compared to barium selenate. This fact can be attributed to the precipitation of barium selenate prior to that of lead selenate, since the latter is more soluble.

Coprecipitation of barium with lead chromate from homogeneous solution

共沈殿現象の一端を解明しようとして,結晶系,溶解度が異なるが組成の類似したクロム酸鉛-バリウム系について検討した.バリウムと鉛の等モル量混合溶液にpH4.5で硝酸クロムと臭素酸カリウムを加えて一定温度で反応させ,いわゆる均一溶液からの沈殿法でクロム酸塩を沈殿させた.溶解度の小さいクロム酸鉛が優先的に沈殿し,バリウムが少量共沈殿した.長時間反応すると,単斜晶系のクロム酸鉛と斜方晶系のクロム酸バリウムが別個に生成した.

Electron Microscopy and Diffraction Studies on the Coprecipitation II&lt;xref ref-type="fn" rid="fn1"&gt;&lt;sup&gt;*&lt;/sup&gt;&lt;/xref&gt;&lt;subtitle&gt;Coprecipitation of Barium and Lead Sulphates&lt;/subtitle&gt;

Coprecipitation of barium and lead sulphate was studied from a stand point of crystallography. To each mixed solution of barium and lead nitrates, whose compositions were 10:0, 7.5:2.5, 5:5, 2.5:7.5 and 0:10 by the mole ratio, ammonium sulphate solution was added. The precipitates were analyzed chemically, by the electron microscopy and by the X-ray diffraction method. Barium and lead sulphates precipitated homogeneously by the conventional precipitation method and heterogeneously by the precipitation from homogeneous solution. The morphological characteristics of precipitated particles changed according to the composition of precipitate. The lattice constants of precipitated crystals also changed gradually by the alteration of the composition of precipitate. It seems that the precipitate was composed of a solid solution of barium and lead sulphates.

Coprecipitation of Barium and Lead Sulfates

Coprecipitation studies have been generally done from a stand point of analytical chemistry, but it is important to study on the coprecipitation from a view point of crystallography to clarify the mechanism of impurification of precipitates.Barium and lead sulfates belong to the orthorhombic system, Vh16, and the spacings of the crystals are slightly different from each other.

Coprecipitation of barium in group II of the qualitative procedure] (the author replies)

ADVERTISEMENT RETURN TO ISSUEPREVLetterNEXT[Coprecipitation of barium in group II of the qualitative procedure] (the author replies)William T. Hall Cite this: J. Chem. Educ. 1944, 21, 4, 200Publication Date (Print):April 1, 1944Publication History Received3 August 2009Published online1 April 1944Published inissue 1 April 1944https://doi.org/10.1021/ed021p200.2RIGHTS & PERMISSIONSArticle Views38Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts

Coprecipitation of barium in group II of the qualitative procedure

Coprecipitation of barium in group II of the qualitative procedure

Coprecipitation of barium in group II of the qualitative procedure

Coprecipitation of barium in group II of the qualitative procedure