scholarly journals Evaluating and Enhancing Iron Removal via Filterable Iron Precipitates Formation during Coal-Waste Bioleaching

Eng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 632-642
Author(s):  
Prasenjit Podder ◽  
Zongliang Zhang ◽  
Rick Q. Honaker ◽  
Michael L. Free ◽  
Prashant K. Sarswat
Keyword(s):  
Iron Removal ◽  
Coal Waste ◽  
X Ray Diffraction ◽  
Visual Minteq ◽  
Phase Purity ◽  
X Ray ◽  
Excess Iron ◽  
Favorable Conditions ◽  
Iron Bearing ◽  
Iron Precipitates

Iron removal via jarosite precipitate formation is a commonly used technique in various hydrometallurgical processes. Excess iron removal often becomes essential to an overall metal recovery circuit. This is particularly important to processes involving iron-bearing minerals. A technique, which involved the use of pyrite to generate acid for leaching, for iron removal is critical to enabling the process. Iron removal using CaO or similar reagents is expensive and often results in lost product. In the present study, various compounds that facilitate jarosite formation, namely Na2SO4, NH4OH, KCl, and KOH, were utilized and their effect in precipitation was observed. Visual Minteq assisted simulations were run in order to evaluate favorable conditions for iron removal. Morphology and elemental composition of precipitates were analyzed using scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and the phase purity was identified using X-ray diffraction analysis.

Gallium-containing Heusler phases ScRh2Ga, ScPd2Ga, TmRh2Ga and LuRh2Ga – magnetic and solid state NMR-spectroscopic characterization

2017 ◽  
Vol 72 (8) ◽  
pp. 609-615
Author(s):  
Lukas Heletta ◽  
Stefan Seidel ◽  
Christopher Benndorf ◽  
Hellmut Eckert ◽  
Rainer Pöttgen
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Spectroscopic Characterization ◽  
Structural Disorder ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Phase Purity ◽  
X Ray ◽  
Arc Melting ◽  
Pauli Paramagnetism

AbstractThe gallium-containing Heusler phases ScRh2Ga, ScPd2Ga, TmRh2Ga and LuRh2Ga have been synthesized by arc-melting of the elements followed by different annealing sequences to improve phase purity. The samples have been studied by powder X-ray diffraction. The structures of Lu0.97Rh2Ga1.03 (Fm3̅m, a=632.94(5) pm, wR2=0.0590, 46 F2 values, seven variables) and Sc0.88Rh2Ga1.12 (a=618.91(4) pm, wR2=0.0284, 44 F2 values, six variables) have been refined from single crystal X-ray diffractometer data. Both gallides show structural disorder through Lu/Ga and Sc/Ga mixing. Temperature dependent magnetic susceptibility measurements showed Pauli paramagnetism for ScRh2Ga, ScPd2Ga, and LuRh2Ga and Curie-Weiss paramagnetism for TmRh2Ga. 45Sc and 71Ga solid state MAS NMR spectroscopic investigations of the Sc containing compounds confirmed the site mixing effects typically observed for Heusler phases. The data indicate that the effect of mixed Sc/Ga occupancy is significantly stronger in ScRh2Ga than in ScPd2Ga.

Phase Development and Dielectric Properties of 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3 Ceramic

2011 ◽  
Vol 700 ◽  
pp. 58-62
Author(s):  
Rachanusorn Roongtao ◽  
Supagorn Rugmai ◽  
Wanwilai C. Vittayakorn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Phase Development ◽  
Scanning Electron

The 0.98BaTiO3-0.02Ba (Mg1/3Nb2/3) O3ceramics has been synthesized through a conventional mixed-oxide by using BT nanopowder and BMN micropowder. The phase purity of the powders and the ceramics was examined using X-ray diffraction (XRD). The 0.98BT-0.02BMN powders were sintered to 92% of the theoretical density at a temperature of 1300 °C for 2 h. The microstructure of the sintered surface was investigated using scanning electron microscopy (SEM). The dielectric constant (εr) and loss factor (tanδ) of the sintered pellets at Curie temperture were 3000 and 0.015, respectively.

scholarly journals Controlled Growth of CdS Nanostep Structured Arrays to Improve Photoelectrochemical Performance

2020 ◽  
Vol 8 ◽  
Author(s):  
Jiangang Jiang ◽  
He Wang ◽  
Hongchang An ◽  
Guangyuan Du
Keyword(s):  
Tin Oxide ◽  
Energy Conversion Efficiency ◽  
Photoelectrochemical Cells ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Photoelectrochemical Performance ◽  
New Approach ◽  
Phase Purity ◽  
X Ray ◽  
Straight Rod

CdS nanostep-structured arrays were grown on F-doped tin oxide-coated glasses using a two-step hydrothermal method. The CdS arrays consisted of a straight rod acting as backbone and a nanostep-structured morphology on the surface. The morphology of the samples can be tuned by varying the reaction parameters. The phase purity, morphology, and structure of the CdS nanostep-structured arrays were characterized by X-ray diffraction and field emission scanning electron microscopy. The light and photoelectrochemical properties of the samples were estimated by a UV-Vis absorption spectrum and photoelectrochemical cells. The experimental results confirmed that the special nanostep structure is crucial for the remarkable enhancement of the photoelectrochemical performance. Compared with CdS rod arrays, the CdS nanostep-structured arrays showed increased absorption ability and dramatically improved photocurrent and energy conversion efficiency. This work may provide a new approach for improving the properties of photoelectrodes in the future.

Detection of Phase Purity of Sr2FeMoO6 by Raman Spectroscopy

2014 ◽  
Vol 989-994 ◽  
pp. 130-133
Author(s):  
Zhen Feng Xu ◽  
Qin Zhang ◽  
Suo Jia Yuan
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Broad Peak ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray

. The micro-Raman technique is used to examine the phase purity of Sr2FeMoO6 compound in this work. It is found that the Raman spectra of Sr2FeMoO6 compound without impurity consists of the peaks at about 440cm-1 and 620cm-1. The broad peak and shoulder at 820-890cm-1 in the Raman spectra is assigned to the most common impurity SrMoO4 and some other unidentified co-existing phases, which is approved by the results of X-ray diffraction.

scholarly journals Methods Comparison for the Synthesis of Deca-Dodecasil 3 Rhombohedral (DDR3) Zeolite Crystals

2015 ◽  
Vol 773-774 ◽  
pp. 1096-1100 ◽  
Author(s):  
Muhammad Mubashir ◽  
Yin Fong Yeong ◽  
Lau Kok Keong ◽  
Azmi bin Mohd Shariff
Keyword(s):  
Room Temperature ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Synthesis Conditions ◽  
Silica Source ◽  
Pre Treatment ◽  
Favorable Conditions ◽  
Scanning Electron ◽  
Zeolite Crystals

In the present work, DDR3 zeolite crystals were synthesized using two different methods. The silica sources used to synthesize DDR3 crystals were tetramethoxysilane (TMOS) and Ludox-40. The resultant samples were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The XRD results showed that the peaks representing DDR3 structure were not obtained for the sample synthesized in 5 days at room temperature with ultrasonic pre-treatment of 3h using Ludox-40 as silica source. On the other hand, the XRD pattern obtained for the sample synthesized in 25 days at 160 o C using TMOS as a silica source were similar with the XRD peaks reported in the literature. From these results, it can be concluded that the synthesis conditions of 25 days at 160 o C using TMOS as silica source were the favorable conditions in obtaining DDR3 crystal structure.

Rietveld Studies on Silicon Substituted Hydroxyapatite

2006 ◽  
Vol 309-311 ◽  
pp. 113-116 ◽  
Author(s):  
Shuo Zou ◽  
Jie Huang ◽  
Serena Best ◽  
William Bonfield
Keyword(s):  
Silicon Content ◽  
Sintering Temperature ◽  
Silicon Concentration ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Similar Dependence ◽  
Initial Silicon ◽  
Distortion Index

Silicon-substituted hydroxyapatite (SiHA) attracts particular interest due its enhanced bioactivity compared with pure hydroxyapatite. In this study we seek to clarify the effects on the lattice parameters of both composition and sintering temperature in experimentally-produced HA and 0.8wt% SiHA, 1.5wt% SiHA and 2.0wt% SiHA sintered at 800oC and 1200oC. X ray diffraction was used to determine the phase purity and crystallographic structure. We found that while the c parameter increased with increasing silicon concentration, the a parameter decreased with initial silicon incorporation then recovered with further increases in silicon incorporation. The calcium (2) channel expanded with silicon incorporation while tetrahedron distortion index (TDI) and the radius of the P channel showed a similar dependence on silicon content as the a parameter.

Influence of Eu2+ Doped Contents on the Spectroscopic Features of Sr2-X MgSi2O7:xEu2+

2012 ◽  
Vol 476-478 ◽  
pp. 1232-1236
Author(s):  
Jia Zhe Guo ◽  
Ya Dong Li ◽  
Yan Lin Huang
Keyword(s):  
Emission Spectra ◽  
Optical Excitation ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Phase Purity ◽  
Reaction Method ◽  
X Ray ◽  
Uv Led

Silicate-based Sr2-xMgSi2O7:xEu2+(x=0.01, 0.03, 0.05, 0.07) phosphors were synthesized by the high temperature solid-state reaction method. Phase purity and crystal structure of the phosphors were characterized using X-ray diffraction spectrometer. The optical excitation and emission spectra of Eu2+ ion were measured using luminescence spectrometer and fluorescence spectrophotometer. The emission spectra showed a strong blue luminescence peaked around 470 nm, corresponds to the 4f65d1 →4f7 transition on Eu2+. Two different average decay time confirmed that the Eu2+ cations may occupy in two different lattice sites and presents different spectroscopic features. With a broad absorption band extending from 224 to 450 nm, it is suggestive that the phosphors have a potential application in UV-LED chips (360-400 nm).

scholarly journals Coordination Polymers of Scandium(III) and Thiophenedicarboxylic Acid

2021 ◽  
Vol 47 (9) ◽  
pp. 593-600
Author(s):  
A. A. Lysova ◽  
V. A. Dubskikh ◽  
K. D. Abasheeva ◽  
A. A. Vasileva ◽  
D. G. Samsonenko ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Coordination Polymers ◽  
Elemental Analysis ◽  
Metal Organic Frameworks ◽  
X Ray Diffraction ◽  
Phase Purity ◽  
X Ray ◽  
Metal Organic

Abstract Three new metal−organic frameworks based on scandium(III) cations and 2,5-thiophenedicarboxylic acid (H2Tdc) are synthesized: [Sc(Tdc)(OH)]·1.2DMF (I), [Sc(Tdc)(OH)]·2/3DMF (II), and (Me2NH2)[Sc3(Tdc)4(OH)2]·DMF (III) (DMF is N,N-dimethylformamide). The structures of the compounds are determined by single-crystal X-ray structure analysis (CIF file CCDC nos. 2067819 (I), 2067820 (II), and 2067821 (III)). The chemical and phase purity of compound I is proved by elemental analysis, thermogravimetry, X-ray diffraction analysis, and IR spectroscopy.

scholarly journals Genesis of langrial iron ore of hazara area, khyber pakhtunkhaw, parkistan

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Naghmah Haider ◽  
Sajjad Khan ◽  
Rehanul Haq Siddiqui ◽  
Shahid Iqbal ◽  
Nazar-Ul -Haq
Keyword(s):  
Iron Ore ◽  
High Energy ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Humid Climate ◽  
X Ray ◽  
High Silica ◽  
Depositional Setting ◽  
Iron Bearing ◽  
Ore Grade

The Iron Ore of Hazara area has been studied at seven locations for detail mineralogical and genesis investigations. Thick bedded iron ore have been observed between Kawagarh Formation and Hangu Formation i.e Cretaceous-Paleocene boundary. At the base of Hangu Formation variable thickness of these lateritic beds spread throughout the Hazara and Kohat-Potwar plateau. This hematite ore exists in the form of unconformity. X-Ray Diffraction technique (XRD), X-ray Fluorescence Spectrometry (XRF), detailed petroghraphic study and Scanning Electron Microscope (SEM) techniques indicated that iron bearing minerals  are hematite,  chamosite and  quartz, albite, clinochlore, illite-montmorillonite, kaolinite, calcite, dolomite and ankerite are the impurities present in these beds. The X-ray Fluorescence (XRF) results show that the total Fe2O3 ranges from 39 to 56% and it has high silica and alumina ratio is less than one. Beneficiation requires for significant increase in ore grade. The petroghraphic study revealed the presence of ooids fragments as nuclei of other ooids with limited clastic supply which indicate high energy shallow marine depositional setting under warm and humid climate. The overall results show that Langrial Iron ore is a low-grade iron ore and can be upgraded up to 62% by applying modern mining techniques to fulfill steel requirements of the country.

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