scholarly journals Utilization of Metallurgy—Beneficiation Combination Strategy to Decrease TiO2 in Titanomagnetite Concentrate before Smelting

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1419
Author(s):  
Pan Chen ◽  
Yameng Sun ◽  
Lei Yang ◽  
Rui Xu ◽  
Yangyong Luo ◽  
...  

Excessive TiO2 in titanomagnetite concentrates (TC) causes unavoidable problems in subsequent smelting. At present, this issue cannot be addressed using traditional mineral processing technology. Herein, a strategy of metallurgy-beneficiation combination to decrease the TiO2 grade in TC before smelting was proposed. Roasting TC with calcium carbonate (CaCO3) together with magnetic separation proved to be a viable strategy. Under optimal conditions (roasting temperature = 1400 °C, CaCO3 ratio = 20%, and magnetic intensity = 0.18 T), iron and titanium was separated efficiently (Fe grade: 56.6 wt.%; Fe recovery: 70 wt.%; TiO2 grade 3 wt.%; TiO2 removal: 84.1 wt.%). X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analysis were used to study the mechanisms. The results showed that Ti in TC could react with CaO to form CaTiO3, and thermodynamic calculations provided a relevant theoretical basis. In sum, the metallurgy-beneficiation combination strategy was proven as an effective method to decrease unwanted TiO2 in TC.

2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.


2009 ◽  
Vol 18 (5) ◽  
pp. 096369350901800 ◽  
Author(s):  
Yahya Bozkurt ◽  
Recep Artir ◽  
Hüseyin Uzun ◽  
Serdar Salman

The present study is focused on the evaluation of the aging behaviour and microstructure characterization of AA2124/SiC/25p composite under the aging temperatures of 180, 185 and 190 °C for various dwelling time ranging from 0 up to 100 hours. The microstructure was characterized by means of scanning electron microscopy. The hardness, energy dispersive spectroscopy analysis and X-ray diffraction measurements were also performed to evaluate the characteristics of aged AA2124/SiC/25p composite. The results show that the hardness values of as-received composite were considerably improved up to two third by the subsequent aging. The hardness increasing was attributed to the presence of CuAl2, Al4SiC4 and precipitation phases in aged AA2124/SiC/25p composite.


2020 ◽  
Vol 32 (11) ◽  
pp. 2739-2742
Author(s):  
Misriyani ◽  
E.S. Kunarti

TiO2 nanotubes (TNTs) were synthesized and modified using the anodization method in a glycerol and ammonium fluoride solution, which was followed by a thermal treatment. The second anodisation was continued by increasing anodizing voltage to deposit a film on the surface of titanium, which resulted in a free standing membrane based on of TNTs. The nanotubes were further characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The SEM result showed that the layer thickness of free standing membrane based on TNTs increased with an increase in the anodizing voltage; however, at high voltages, this layer was damaged. The XRD and FTIR results indicated the generation of TNT having an anatase crystal phase. The results of test for photoelectrochemical properties showed that the optimal conditions of anodizing voltage was 50 V maintained for 1 h.


2019 ◽  
Vol 2 (2) ◽  
pp. 65-76
Author(s):  
Tahereh Poursaberi ◽  
Ali Akbar Miran Beigi

This study investigates an application of zinc metalloporphyrin grafted Fe3O4 nanoparticles as a new adsorbent for removal of sulfate ions from wastewaters. The modification of magnetite nanoparticles was conducted by 3-aminopropyltriethoxysilane followed by zinc (II) porphyrin in order to enhance the removal of sulfate ions. Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) was used to characterize the synthesized nano sorbent. The effect of important experimental factors such as pH, contact time, sorbent dosage and some co-existing anions present in aqueous solutions were investigated. Under optimal conditions (i.e. contact time: 30 min, pH: 6.5 and nanosorbents dosage: 100 mg) for a sulfate sample (50 mL, 50 mgL-1 ) the percentage of the extracted sulfate ions was 94.5%. Regeneration of sulfate adsorbed material could be possible by NaOH solution and the modified magnetic nano sorbent exhibited good reusability.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
R. J. Narconis ◽  
G. L. Johnson

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.


2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.


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