scholarly journals Phase Development in the Sintering of a Hematite–Ilmenite Ore Blend

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 800
Author(s):  
Edson K. Chiwandika ◽  
Seong-Kyu Cho ◽  
Sung-Mo Jung
Keyword(s):  
Glass Phase ◽  
Sintering Behavior ◽  
Low Grade ◽  
Iron Ores ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Development ◽  
Sinter Bonding ◽  
Hematite Ore ◽  
Increasing Temperature

The use of low-grade iron ores has attracted a lot of interest where fines from these ores are sintered to improve their strength. Ti-containing ores are one of the abundantly available iron ores of low-grade. The sintering of the hematite–ilmenite ore blends has several challenges, which include the formation of perovskite. The sintering behavior of a hematite–ilmenite ore sinter blend was investigated in 75 vol% N2, 24 vol% CO2, and 1 vol% CO in the temperature range of 1373 to 1523 K. Phase development and distribution of metallic elements were investigated by x-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and electron probe microanalysis (EPMA). The addition of ilmenite ore to hematite ore increased the temperature of melt formation. More titanium (Ti) was distributed in the glass phase with increasing temperature. Morphological change showed that the amount of sinter-bonding phase generated was low, below 1473 K. Weak sinter bonding strength might be caused by the presence of Ti in the glass phase at high temperature. This might affect the fracture toughness of the glass phase.

scholarly journals Genesis of Langrial Iron Ore of Hazara area, Khyber Pakhtunkhwa, Pakistan

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

In this paper, a detailed mineralogical and genesis investigation have been carried out in the seven locations of the Iron Ore in Hazara area. 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 those iron bears minerals including hematite, chamosite and quartz, albite, clinochlore, illite-montmorillonite, kaolinite, calcite, dolomite, whereas ankerite are the impurities present in these beds. The X-ray fluorescence (XRF) results show that the total Fe2O3 ranges from 39 to 56%, with high silica and alumina ratio of 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 which can be upgraded up to 62% by applying modern mining techniques so as to fulfill steel requirements of the country.

scholarly journals Extraction of Boron from Ludwigite Ore: Mechanism of Soda-Ash Roasting of Lizardite and Szaibelyite

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 533 ◽  
Author(s):  
Xin Zhang ◽  
Guanghui Li ◽  
Jinxiang You ◽  
Jian Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Energy Dispersive Spectrometer ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Selective Activation ◽  
X Ray ◽  
Shed Light ◽  
Soda Ash ◽  
Scanning Electron

Ludwigite ore is a typical low-grade boron ore accounting for 58.5% boron resource of China, which is mainly composed of magnetite, lizardite and szaibelyite. During soda-ash roasting of ludwigite ore, the presence of lizardite hinders the selective activation of boron. In this work, lizardite and szaibelyite were prepared and their soda-ash roasting behaviors were investigated using thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope and energy dispersive spectrometer (SEM-EDS) analyses, in order to shed light on the soda-ash activation of boron within ludwigite ore. Thermodynamics of Na2CO3-MgSiO3-Mg2SiO4-Mg2B2O5 via FactSage show that the formation of Na2MgSiO4 was preferential for the reaction between Na2CO3 and MgSiO3/Mg2SiO4. While, regarding the reaction between Na2CO3 and Mg2B2O5, the formation of NaBO2 was foremost. Raising temperature was beneficial for the soda-ash roasting of lizardite and szaibelyite. At a temperature lower than the melting of sodium carbonate (851 °C), the soda-ash roasting of szaibelyite was faster than that of lizardite. Moreover, the melting of sodium carbonate accelerated the reaction between lizardite with sodium carbonate.

Study of Low-Grade Nickel Laterite Processing Using Palm Shell Charcoal as Reductant

2020 ◽  
Vol 1000 ◽  
pp. 436-446
Author(s):  
Bambang Suharno ◽  
Nolzha Primadha Ilman ◽  
Achmad Shofi ◽  
Deni Ferdian ◽  
Fajar Nurjaman
Keyword(s):  
Sodium Sulfate ◽  
Selective Reduction ◽  
Reduction Process ◽  
Low Grade ◽  
X Ray Diffraction ◽  
X Ray ◽  
Palm Shell ◽  
Higher Temperature ◽  
Nickel Grade

This study was conducted to investigate the effect of palm shell charcoal reductant in the selective reduction of nickel ore with the addition of additive at various temperatures and times. In this present work, 10 wt. % of sodium sulfate as additive and 5, 10, 15 wt. % of palm shell charcoal as reductants were used. The reduction of nickel ore was performed at 950oC, 1050oC, and 1150oC for 60, 90, and 120 minutes. A wet magnetic separation method was then carried out to separate the concentrates and tailings. Characterization of reduced ore was performed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), while the composition of ferronickel in concentrate was identified by X-Ray Fluorescence (XRF). The result showed that the higher temperature reduction, the higher of nickel grade, and its recovery at the concentrate. Nevertheless, the longer reduction time and the more reductant in nickel ore lowering the nickel grade and its recovery in the concentrate. The optimum condition in this selective reduction process was obtained with the addition of 5 wt. % of reductant and 10 wt. % of sodium sulfate in nickel ore, which was reduced at 1150oC for 60 minutes. It resulted in 4.60% and 73.23% for nickel grade and its recovery, respectively.

Polydomain Structure of Epitaxial PbTiO3 films on MgO

1997 ◽  
Vol 493 ◽  
Author(s):  
S. P. Alpay ◽  
A. S. Prakash ◽  
S. Aggarwal ◽  
R. Ramesh ◽  
A. L. Roytburd ◽  
...  
Keyword(s):  
Domain Structure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Theoretical Predictions ◽  
The Stability ◽  
Increasing Temperature ◽  
Stable Domains ◽  
Domain Stability

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.

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 Structural and thermoelectric properties of the Pr2Zr2O7 compound

2019 ◽  
pp. 4-9
Author(s):  
Adolfo Quiroz-Rodríguez ◽  
Cesia Guarneros-Aguilar ◽  
Ricardo Agustin-Serrano
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Crystal Size ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Scanning Electron

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

scholarly journals Stabilization Study of a Contaminated Soil with Metal(loid)s Adding Different Low-Grade MgO Degrees

2020 ◽  
Vol 12 (18) ◽  
pp. 7340
Author(s):  
Jessica Giro-Paloma ◽  
Joan Formosa ◽  
Josep M Chimenos
Keyword(s):  
Contaminated Soil ◽  
Contaminated Soils ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Optimal Stabilization ◽  
X Ray ◽  
Neutralization Capacity ◽  
Stabilizing Agents ◽  
Acid Test ◽  
By Products

Low-grade magnesium oxide (LG-MgO) was proposed as ordinary Portland cement (OPC) or lime substitute (CaO) for metal(loid)s remediation in contaminated soils. Some metal(loid)s precipitate at pH ≈ 9 in insoluble hydroxide form thus avoiding their leaching. LG-MgO avoids the re-dissolution of certain metal(loid)s at 9.0 < pH < 11.0 (pH-dependents), whose solubility depends on the pH. A highly contaminated soil with heavy metal(loid)s was stabilized using different LG-MgO by-products sources as stabilizing agents. Two of the three studied LG-MgOs were selected for the stabilization, by mixing 5, 10, and 15 wt.%. The effect of using LG-MgO not only depends on the size of the particles, but also on those impurities that are present in the LG-MgO samples. Particle size distribution, X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis, citric acid test, specific surface, bulk density, acid neutralization capacity, batch leaching tests (BLTs), and percolation column tests (PCTs) were techniques used to deeply characterize the different LG-MgO and the contaminated and remediated soils. The remediation’s results efficacy indicated that when the medium pH was between 9.0 and 11.0, the concentration of pH-dependent metal(loid)s decreases significantly. Although around 15 wt.% of a stabilizing agent was appropriate for the soil remediation to ensure an alkali reservoir that maintains optimal stabilization conditions for a long period, 5 wt.% of LG-MgO was enough to remedy the contaminated soil. When evaluating a polluted and decontaminated soil, both BLTs and PCTs should be complementary procedures.

scholarly journals Liberation Characteristics of Ta–Sn Ores from Penouta, NW Spain

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 509
Author(s):  
Pura Alfonso ◽  
Sarbast Ahmad Hamid ◽  
Hernan Anticoi ◽  
Maite Garcia-Valles ◽  
Josep Oliva ◽  
...  
Keyword(s):  
White Mica ◽  
Low Grade ◽  
Economic Interest ◽  
X Ray Diffraction ◽  
Nw Spain ◽  
X Ray ◽  
Mineral Associations ◽  
Ore Minerals ◽  
Automated Mineralogy ◽  
Scanning Electron

The strategic importance of tantalum and its scarcity in Europe makes its recovery from low grade deposits and tailings interesting. In Penouta, the contents of Ta and Sn in old tailings from an Sn mine are of economic interest. Due to the relatively low grade of Ta of around 100 ppm, a detailed study of the mineralogy and liberation conditions is necessary. In this study, the mineralogy and the liberation characteristics of Sn and Ta ores of the Penouta tailings were investigated and compared with the current leucogranite outcropping ores. The characterization was conducted through X-ray diffraction, scanning electron microscopy, and electron microprobe. In addition, automated mineralogy techniques were used to determine the mineral associations and liberation characteristics of ore minerals. The grade of the leucogranite outcropping was found to be about 80 ppm for Ta and 400 ppm for Sn, and in the tailings used for the liberation study, the concentrations of Ta and Sn were about 100 ppm Ta and 500 ppm Sn, respectively. In both, the leucogranite outcropping and tailings, the major minerals found were quartz, albite, K-feldspar, and white mica. Ore minerals identified were columbite-group minerals (CGM), microlite, and cassiterite. The majority of CGM examined were associated with cassiterite, quartz, and muscovite particle compositions and cassiterite was mainly associated with CGM, quartz, and muscovite. The liberation size was 180 µm for CGM.

Synthesis and Characterization of 3Y-TZP by Gel Solid-State Method

2011 ◽  
Vol 412 ◽  
pp. 61-64
Author(s):  
Xiao Bo Wu ◽  
Da Zhi Sun ◽  
Dan Yu Jiang ◽  
Hai Fang Xu ◽  
De Xin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray ◽  
Powder Particles ◽  
State Method ◽  
Average Size

3Y-TZP powder has been successfully synthesized by gel solid-state method. The structural phases of powder particles were analyzed by X-ray diffraction and the morphology was analyzed by scanning electron microscopy. The average size of grains was 230 nm. The sintering behavior, mechanical properties and microstructure of 3Y-TZP ceramics sintered by this powder were investigated. The experiment results showed that the mechanical properties of ceramics were excellent.

Ferromagnetic properties and Nanocrystallization behavior of Amorphous (Fe0.99Mo0.01)78Si9B13 Ribbons

2001 ◽  
Vol 674 ◽  
Author(s):  
Xiang-Cheng Sun ◽  
J. A. Toledo ◽  
S. Galindo ◽  
W. S. Sun
Keyword(s):  
Amorphous Phase ◽  
Magnetic Ordering ◽  
Metastable Phases ◽  
X Ray Diffraction ◽  
Ferromagnetic Properties ◽  
X Ray ◽  
Diffraction Patterns ◽  
Optimum Annealing Temperature ◽  
Increasing Temperature ◽  
Differential Scanning Calorimeters

ABSTRACTFerromagnetic properties and nanocrystallization process of soft ferromagnetic (Fe0.99Mo0.01)78Si9B13 ribbons are studied by transmission electron microscope (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy (MS), differential scanning calorimeters (DSC) and magnetization measurements. The Curie and crystallization temperature are determined to be TC=665K and Tx = 750K, respectively. The Tx value is in well agreement with DSC measurement results. X-ray diffraction patterns had shown a good reconfirm of two metastable phases (Fe23B6, Fe3B) were formed under in-situ nanocrystallization process. Of which these metastable phases embedded in the amorphous matrix have a significant effect on magnetic ordering. The ultimate nanocrystalline phases of α-Fe (Mo, Si) and Fe2B at optimum annealing temperature had been observed respectively. It is notable that the magnetization of the amorphous phase decreases more rapidly with increasing temperature than those of nanocrystalline ferromagnetism, suggesting the presence of the distribution of exchange interaction in the amorphous phase or high metalloid contents.

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