The Investigation of Coke Breeze Demineralization on Temperature

2012 ◽  
Vol 581-582 ◽  
pp. 1123-1126
Author(s):  
Zhe Ning ◽  
Ke Qiang Xie ◽  
Wen Hui Ma ◽  
Kui Xian Wei ◽  
Yang Zhou ◽  
...  
Keyword(s):  
Element Content ◽  
Coke Breeze ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
Two Stage ◽  
Chemical Leaching ◽  
X Ray ◽  
Alkali Leaching

The high ash coke breeze was leaching by two-stage chemical leaching. X-ray diffraction (XRD) and X-Ray Fluorescence (XRF) were employed to characterize the mineral phase and the element content respectably. More than 80% ash has been removed from the coke breeze by two-stage leaching. The removal of Si and Al was significantly affected by the temperature of alkali leaching. The mineral phase of the result coke breeze is similar to that of the raw ash except with cristobalite and sodium mica.

scholarly journals A crystallographic study of crystalline casts and pseudomorphs from the 3.5 Ga Dresser Formation, Pilbara Craton (Australia)

2018 ◽  
Vol 51 (4) ◽  
pp. 1050-1058 ◽  
Author(s):  
Fermin Otálora ◽  
A. Mazurier ◽  
J. M. Garcia-Ruiz ◽  
M. J. Van Kranendonk ◽  
E. Kotopoulou ◽  
...  
Keyword(s):  
High Temperature ◽  
Geological History ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
X Ray ◽  
Crystallographic Study ◽  
History Of ◽  
Degree Of Confidence ◽  
High Degree ◽  
Pilbara Craton

Crystallography has a long history of providing knowledge and methods for applications in other disciplines. The identification of minerals using X-ray diffraction is one of the most important contributions of crystallography to earth sciences. However, when the crystal itself has been dissolved, replaced or deeply modified during the geological history of the rocks, diffraction information is not available. Instead, the morphology of the crystal cast provides the only crystallographic information on the original mineral phase and the environment of crystal growth. This article reports an investigation of crystal pseudomorphs and crystal casts found in a carbonate-chert facies from the 3.48 Ga-old Dresser Formation (Pilbara Craton, Australia), considered to host some of the oldest remnants of life. A combination of X-ray microtomography, energy-dispersive X-ray spectroscopy and crystallographic methods has been used to reveal the original phases of these Archean pseudomorphs. It is found with a high degree of confidence that the original crystals forming in Archean times were hollow aragonite, the high-temperature polymorphs of calcium carbonate, rather than other possible alternatives such as gypsum (CaSO4·2H20) and nahcolite (NaHCO3). The methodology used is described in detail.

A Novel Technique of Flyash Utilization: Preparation of Silica from Flyash by Alkali Leaching

2010 ◽  
Vol 434-435 ◽  
pp. 814-815
Author(s):  
An Ran Guo ◽  
Jia Chen Liu ◽  
Yi Bing Sun ◽  
Wen Jun Lian ◽  
Lu Yang
Keyword(s):  
High Purity ◽  
Sodium Hydroxide Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Technique ◽  
Reinforcing Agent ◽  
Alkali Leaching ◽  
A New Technique ◽  
Fluorescence Spectrometer ◽  
Scanning Electron

A new technique of flyash utilization was presented and high-purity silica was prepared by alkali leaching. The flyash was added into sodium hydroxide solution, and then the suspension was heated to 115 °C for 30 min. After filtrated, the filtrate was collected and carbon dioxide was imported into the solution. Finally, the silica would precipitate from the solution. The silica was characterized by scanning electron microscopy, X-ray diffraction and X-ray fluorescence spectrometer. The high-purity silica prepared from flyash was qualified for the rubber reinforcing agent used in shoemaking.

The Study on the Mineral Phase Transformations and Thermodynamics of Laterite Ores Calcination

2013 ◽  
Vol 813 ◽  
pp. 250-254
Author(s):  
Yu Ling Xu ◽  
Song Chen ◽  
Shu Qiang Gui ◽  
Yu Yang Bian ◽  
Wei Zhong Ding ◽  
...  
Keyword(s):  
Phase Transformations ◽  
X Ray Diffraction ◽  
Nickel Laterite ◽  
Mineral Phase ◽  
Structural Water ◽  
Calcination Process ◽  
X Ray ◽  
Laterite Ores ◽  
Higher Temperature ◽  
Mineralogical Phase

In this paper, mineralogical phase transformations of Indonesia nickel laterite ores are studied during calcinations, the thermodynamics of process are also investigated. Different factors that affect the reduction of the laterite ores are tested and analyzed by Differential Scanning Calorimeter (DSC), X-ray Diffraction (XRD), Brunauer Emmett Teller (BET) and Scanning Electron Microscope (SEM). The results show that during calcination process, goethite is dehydrolyzed by removing structural water at about 300°C, which then transforms to hematite, and serpentine decomposes at around 600~700°C, leading to formulate olivine if agglomerating at higher temperature. By thermodynamics calculation, the goethite dehydration temperature is under 100°C, and about 200°C for serpentine decomposition. It might be the inclusions in ore which make laterite become hard to decompose.

scholarly journals Performances of vermiculite and perlite based thermal insulation lightweight concretes

2020 ◽  
Vol 52 (2) ◽  
pp. 149-162
Author(s):  
Anja Terzic ◽  
Jovica Stojanovic ◽  
Ljubisa Andric ◽  
Ljiljana Milicic ◽  
Zagorka Radojevic
Keyword(s):  
Phase Composition ◽  
Thermal Insulation ◽  
Mix Design ◽  
Expanded Perlite ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
X Ray ◽  
Expanded Vermiculite ◽  
Concrete Mix ◽  
Aluminate Cement

This experimental study was conducted with an aim to investigate the effect of the elevated temperature on the mineral phase composition, microstructure and mechanical properties of the thermal insulation lightweight concretes. The first group of experimental concretes was based on the expanded vermiculite and expanded perlite used as lightweight aggregates (in 65 wt%) in combination with either ordinary Portland cement or refractory calcium aluminate cement. The mix-design of the second group of concretes comprised standard quartz aggregate, vermiculite or perlite as aggregate replacement (25 wt%) and binder (PC or CAC). A total of 10 concrete mix-designs were fabricated in form of 40?40?160 mm samples which were submitted to heat-treatment at 400?, 600?, 800? and 1000?C upon standard 28-days period of curing and hardening. The changes in crystallinity and mineral phase composition induced by temperature were monitored by X-ray diffraction technique. Microstructural visualizations of the non-fired and fired concrete samples were conducted by scanning electron microscopy accompanied with EDX analysis. The results indicated that despite the decrease in compressive strengths upon firing, investigated lightweight concretes can be categorized both as thermal insulators and structural materials.

scholarly journals Nacre morphology and chemical composition in Atlantic winged oyster Pteria colymbus (Röding, 1798)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11527
Author(s):  
Pablo Santana ◽  
Dalila Aldana Aranda
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Organic Matrix ◽  
Carbonyl Groups ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
X Ray ◽  
Minor Elements ◽  
Scanning Electron

The microstructure and nanostructure of nacre in Pteria colymbus were studied with high-resolution field emission scanning electron microscopy (FESEM). The tablets were found to be flat and polyhedral with four to eight sides, and lengths ranging from 0.6 to 3.0 µm. They consisted of nanocrystals 41 nm wide, growing in the same direction. X-ray diffraction showed the crystals to be mineral phase aragonite, which was confirmed by Raman spectroscopy. Fourier transform infrared spectroscopy identified a band at 1,786.95 cm−1 attributed to carboxylate (carbonyl) groups of the proteins present in the organic matrix as well as bands characteristic of calcium carbonate. X-ray fluorescence showed the nacre to contain 98% calcium carbonate, as well as minor elements (Si, Na, S and Sr) and trace elements (Mg, P, Cu, Al, Fe, Cl, K and Zn).

scholarly journals Study on the Sulfuration Mechanism of Concrete: Microstructure and Product Analysis

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3386
Author(s):  
Ditao Niu ◽  
Yao Lv ◽  
Xiguang Liu ◽  
Lei Chen ◽  
Guoxin Chen ◽  
...  
Keyword(s):  
Pore Solution ◽  
X Ray Diffraction ◽  
Product Analysis ◽  
Mineral Phase ◽  
Mass Percentage ◽  
Solution Ph ◽  
Continuous Increase ◽  
X Ray ◽  
Initial Stage ◽  
Caco3 Content

This paper presents an experimental investigation of the sulfuration mechanism of concrete. The microstructure, mineral phase composition, substance content, and pH of the concrete were determined using scanning electron microscopy, X-ray diffraction, comprehensive thermal analysis, and pore-solution pH test. It was observed that light-grey spots appeared on the surface of the specimen, and a large amount of powdery precipitated substances appeared. At the initial stage of sulfuration reaction, the formation of ettringite blocked the concrete pores and densified its cracks and voids. Subsequently, ettringite reacted with H+ to form gypsum, and the continuous increase in gypsum in the pores increased the number of cracks and broadened their width. Gypsum was the final product of the sulfuration reaction, and the mass percentage of gypsum in the powdery precipitated substances at different water–cement ratios was more than 50%. When the water–cement ratios was 0.37, 0.47, and 0.57, the highest Ca(OH)2 content was found for the lowest water–cement ratio. As the water–cement ratios increased, the amount of powdery precipitated substances decreased and the CaCO3 content and pH increased.

Mapping the density and mineral phase of calcium in bone at the interface with biomaterials using scanning x-ray microscopy

1994 ◽  
Vol 52 ◽  
pp. 44-45
Author(s):  
C. J. Buckley ◽  
S. Downes ◽  
N. Khaleque ◽  
S. J. Bellamy ◽  
X. Zhang
Keyword(s):  
Bone Mineral ◽  
Calcium Phosphates ◽  
X Ray Diffraction ◽  
Mineral Phase ◽  
X Ray ◽  
Prosthetic Implants ◽  
Chemical Phase ◽  
Infra Red ◽  
Rapid Healing ◽  
Prosthetic Implant

Orthopaedic surgery often involves the insertion of a prosthetic implant. For successful and rapid healing, it is important for the prosthesis to make a close and well integrated bond with the bone tissue. To assist this integration, a number of “biomaterials” are on trial as components in the prosthetic implants. Much work is in progress to determine the phase, composition and density of bone mineral at the bone/biomaterial interface. It is expected that the results of this work can be used to develop synthetic calcium phosphates which can be incorporated in prosthetic implants. The composition of bone and biomaterials has been investigated using techniques such as x-ray diffraction, Infra-red, NMR and EXAFS on homogenized samples. However, these studies do not determine the spatial distribution of the bone mineral, its density, localized mineral phase or cellular integration with biomaterials. Electron microscopy with electron probe microanalysis, light and Infra-red microscopy can indicate the presence of mineral in relation to the tissue morphology, but do not give a spatial measure of the density or chemical phase of the mineral at the sub micron level.

scholarly journals Two-Stage Hydrogen Compression Using Zr-Based Metal Hydrides

2012 ◽  
Vol 194 ◽  
pp. 249-253 ◽  
Author(s):  
Evangelos D. Koultoukis ◽  
Sofoklis S. Makridis ◽  
Daniel Fruchart ◽  
Athanasios K. Stubos
Keyword(s):  
High Pressure ◽  
Metal Hydrides ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
Two Stage ◽  
X Ray ◽  
Phase Type ◽  
Edx Analyses ◽  
Type Apparatus

Zr-based AB2-Laves phase type alloys containing the same type of A and B metals, have been prepared from pure elements by melting and subsequent re-melting under argon atmosphere by using a HF-induction levitation furnace. Characterization of the alloys has resulted from powder X-Ray Diffraction (XRD) measurements and SEM/EDX analyses. Systematic PCI (Pressure-Composition-Isotherms) measurements have been recorded at 20 and 90 °C, using a high-pressure Sievert's type apparatus. The purpose of this study is to find a series of alloys promptly forming metal hydrides (MH) with suitable properties in order to build a MH-based hydrogen compressor, working in the same way between 20 and ~100 °C.

Synthesis and Optimization of TiO2 Nano Crystals by Gel-Casting Method

2010 ◽  
Vol 11 ◽  
pp. 73-77
Author(s):  
A.A. Rohani ◽  
M. Tabrizi ◽  
S. Manafi ◽  
H. Badiei
Keyword(s):  
Rutile Phase ◽  
X Ray Diffraction ◽  
Casting Method ◽  
Calcination Time ◽  
Mineral Phase ◽  
X Ray ◽  
Preparation Conditions ◽  
Gel Casting ◽  
Concentration Time ◽  
Structure Morphology

In this study, titania (TiO2) nano powders were synthesized by a new method. TiO2 nano-sized powders were prepared by a gel-casting method. Crystalline structure, morphology and mineral phase analysis of TiO2 powder have been characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Results show that different preparation conditions of gel such as reactants concentration, accelerator, starter concentration, time and temperature of calcination have a large influence on the properties of the produced powder. Calcination time and temperature can improve the crystallization of TiO2 powders and can be an accelerator factor for converting amorphous phase to anatase or rutile phase. The results obtained show that the anatase to rutile transformation is started at about 750oC and the best size of produced powder grain is 20-25 nm.

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