scholarly journals Crystalline Phases in the Waste Foundry Sands Based on Quartz Sand Matrix

2018 ◽  
Vol 21 (3) ◽  
pp. 213-226
Author(s):  
Iwona Jonczy ◽  
◽  
Małgorzata Kamińska ◽  
Katarzyna Bilewska ◽  
Anna Gerle ◽  
...  
Keyword(s):  
Quartz Sand ◽  
Crystalline Phases ◽  
Foundry Sands

scholarly journals Composition Optimization of Glass-Like Casing and Its Novel Application in Mending Instable Borehole Wall

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Zhi-jun Li ◽  
Yu Wang ◽  
Bao-lin Liu ◽  
Chun Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Differential Scanning Calorimeter ◽  
Compression Strength ◽  
Quartz Sand ◽  
Borehole Wall ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Composition Optimization

A glass-like casing was developed to mend the instable borehole due to its great similarities in compositions and structure. In order to boost the casing’s mechanical properties and lower its cost, different wt% additions of aluminum and quartz sand are added into the composition. Based on the outcomes of differential scanning calorimeter (DSC), it is suggested to be sintered at the temperature of 700°C. The results of X-ray diffraction (XRD) show that aluminum and SiO2are its main crystalline phases. Its compression strength and the tensile strength range 5–14 Mpa and 0.5–4.5 Mpa, respectively, with the relative densities of between 1.00 g/cm3and 1.19 g/cm3. In the end, a glass-based formula with 30 wt% aluminum and 40 wt% quartz sand is developed and experimentally applied.

Investigation of complex permittivity spectra of foundry sands

2020 ◽  
Vol 87 (5) ◽  
pp. 372-380
Author(s):  
Luca Bifano ◽  
Alice Fischerauer ◽  
Gerhard Fischerauer
Keyword(s):  
Quartz Sand ◽  
Control Strategies ◽  
Equivalent Circuit Model ◽  
Impedance Spectrum ◽  
Nyquist Plot ◽  
Impedance Spectra ◽  
Foundry Sands ◽  
Different Types ◽  
Regeneration Processes

AbstractThis paper discusses impedance spectroscopy as a method to characterize different types of quartz sand, chromite sand, and mixtures of sand. Based on two types of measurement cells, the impedance spectra for various dry sands were measured. The spectra differ enough to allow the sands to be distinguished. The results were validated by extracting the relative permittivity from the impedance and comparing it to literature data. After that, the method could be applied with confidence to other material systems. The influence of moisture was investigated with two types of quartz sand, and typical mixtures of form sand, chromite sand, and regenerated (quartz) sand were studied. In each case, the sand composition had a distinct influence on the Nyquist plot of the impedance spectrum. Compared to results from a laboratory foundry system, the new method exhibits a much more systematic dependence on the sand composition. If one succeeds in describing the impedance spectra with an equivalent circuit model parameterized by only a few parameters, these parameters could be used to identify and classify sand mixtures in the field. This would allow one, for example, to implement feedback control strategies in foundry regeneration processes, which would stabilize the processes and improve the quality of the casting products.

Chemical Classification and Particle Sizing of Foundry Sands

1985 ◽  
Vol 43 ◽  
pp. 388-389
Author(s):  
D.S. DeMiglio
Keyword(s):  
Image Analysis ◽  
Energy Dispersive Spectrometer ◽  
Image Analysis System ◽  
Representative Sampling ◽  
Foundry Sands ◽  
Large Atomic Number ◽  
Backscattered Electron ◽  
Sand Particles ◽  
Analysis System ◽  
Reclamation System

Much progress has been made in recent years towards the development of closed-loop foundry sand reclamation systems. However, virtually all work to date has determined the effectiveness of these systems to remove surface clay and metal oxide scales by a qualitative inspection of a representative sampling of sand particles. In this investigation, particles from a series of foundry sands were sized and chemically classified by a Lemont image analysis system (which was interfaced with an SEM and an X-ray energy dispersive spectrometer) in order to statistically document the effectiveness of a reclamation system developed by The Pangborn Company - a subsidiary of SOHIO.The following samples were submitted: unreclaimed sand; calcined sand; calcined & mechanically scrubbed sand and unused sand. Prior to analysis, each sample was sprinkled onto a carbon mount and coated with an evaporated film of carbon. A backscattered electron photomicrograph of a field of scale-covered particles is shown in Figure 1. Due to a large atomic number difference between sand particles and the carbon mount, the backscattered electron signal was used for image analysis since it had a uniform contrast over the shape of each particle.

Hydrothermal Synthesis and Solid-State Laser Refrigeration of Ytterbium-Doped Potassium Lutetium Fluoride (KLF) Microcrystals

2020 ◽  
Author(s):  
Xiaojing Xia ◽  
Anupum Pant ◽  
Xuezhe Zhou ◽  
Elena Dobretsova ◽  
Alex Bard ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Solid State ◽  
Information Science ◽  
Point Group ◽  
Solid State Laser ◽  
Lanthanide Ions ◽  
Group Symmetry ◽  
Luminescence Spectra ◽  
Crystalline Phases ◽  
State Laser

Fluoride crystals, due to their low phonon energies, are attractive hosts of trivalent lanthanide ions for applications in upconverting phosphors, quantum information science, and solid-state laser refrigeration. In this article, we report the rapid, low-cost hydrothermal synthesis of potassium lutetium fluoride (KLF) microcrystals for applications in solid-state laser refrigeration. Four crystalline phases were synthesized, namely orthorhombic K<sub>2</sub>LuF<sub>5</sub> (Pnma), trigonal KLuF<sub>4</sub> (P3<sub>1</sub>21), orthorhombic KLu<sub>2</sub>F<sub>7</sub> (Pna2<sub>1</sub>), and cubic KLu<sub>3</sub>F<sub>10</sub> (Fm3m), with each phase exhibiting unique microcrystalline morphologies. Luminescence spectra and emission lifetimes of the four crystalline phases were characterized based on the point-group symmetry of trivalent cations. Laser refrigeration was measured by observing both the optomechanical eigenfrequencies of microcrystals on cantilevers in vacuum, and also the Brownian dynamics of optically trapped microcrystals in water. Among all four crystalline phases, the most significant cooling was observed for 10%Yb:KLuF<sub>4</sub> with cooling of 8.6 $\pm$ 2.1 K below room temperature. Reduced heating was observed with 10%Yb:K<sub>2</sub>LuF<sub>5</sub>

SURVEI POTENSI PASIR KUARSA DI DAERAH KETAPANG PROPINSI KALIMANTAN BARAT

2012 ◽  
Vol 11 (2) ◽  
Author(s):  
Teguh Prayogo ◽  
Bayu Budiman
Keyword(s):  
Glass Industry ◽  
Quartz Sand ◽  
Mineral Resources ◽  
Cement Industry ◽  
Laboratory Analysis ◽  
Rock Weathering ◽  
West Kalimantan ◽  
White Sand ◽  
Quartz Sands ◽  
Industrial Mineral

Ketapang area is one of lower part or southern sub-province of West Kalimanatan Province, which is located geographically between 108o40’ and 111o20’ in Longitude and between 0o20’ and 3o04’ in Latitude. This area has various of industrial mineral resources, for example quartz sand. Quartz sand or also calledwith white sand is the reasult of rock weathering that contents main mineral, such as quartz, and felsdpar. Then, the result of weathering is cleaned and transported by water or wind and deposited in the stream side, lake or sea. In this paper will bedescribed concerning to locations, characteristics, and usages of quratz sand in Ketapang area, West Kalimantan Province. Based on chemical or laboratory analysis and interpretation, the quartz sands can be used as glass industry, cement industry material, and moulding industry.

The model rotator phase

1988 ◽  
Vol 53 (5) ◽  
pp. 889-902
Author(s):  
Josef Šebek
Keyword(s):  
High Temperature ◽  
Partition Function ◽  
Conformational Flexibility ◽  
Small Probability ◽  
Crystalline Phases ◽  
Rotator Phase

It is shown that the formation of the so-called rotator phase of alkanes (one of the high temperature crystalline phases) might be connected with a partial increase of the conformational flexibility of chains. The conformations with higher number of kinks per chain, which have been neglected till now, are shown to contribute effectively to the conformational partition function. Small probability of these states given by the Boltzmann exponent is compensated by a large number of ways in which they can be distributed along the chain. The deduced features of the rotator phase seem to be in agreement with the experimentally observed properties.

scholarly journals Crystalline Phases Relating to Stable Al–Cu–Fe Quasicrystal

1990 ◽  
Vol 31 (12) ◽  
pp. 1033-1040 ◽  
Author(s):  
V. S. Raghunathan ◽  
D. Sundararaman ◽  
R. Divakar
Keyword(s):  
Crystalline Phases

scholarly journals Eco-Friendly Colloidal Aqueous Sol-Gel Process for TiO2 Synthesis: The Peptization Method to Obtain Crystalline and Photoactive Materials at Low Temperature

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 768
Author(s):  
Julien G. Mahy ◽  
Louise Lejeune ◽  
Tommy Haynes ◽  
Stéphanie D. Lambert ◽  
Raphael Henrique Marques Marcilli ◽  
...  
Keyword(s):  
Organic Pollutant ◽  
Sol Gel ◽  
Synthesis Method ◽  
Specific Treatment ◽  
High Specific Surface Area ◽  
Crystalline Phases ◽  
Tio2 Photocatalysts ◽  
Tio2 Anatase ◽  
Synthesis Parameters ◽  
Calcination Step

This work reviews an eco-friendly process for producing TiO2 via colloidal aqueous sol–gel synthesis, resulting in crystalline materials without a calcination step. Three types of colloidal aqueous TiO2 are reviewed: the as-synthesized type obtained directly after synthesis, without any specific treatment; the calcined, obtained after a subsequent calcination step; and the hydrothermal, obtained after a specific autoclave treatment. This eco-friendly process is based on the hydrolysis of a Ti precursor in excess of water, followed by the peptization of the precipitated TiO2. Compared to classical TiO2 synthesis, this method results in crystalline TiO2 nanoparticles without any thermal treatment and uses only small amounts of organic chemicals. Depending on the synthesis parameters, the three crystalline phases of TiO2 (anatase, brookite, and rutile) can be obtained. The morphology of the nanoparticles can also be tailored by the synthesis parameters. The most important parameter is the peptizing agent. Indeed, depending on its acidic or basic character and also on its amount, it can modulate the crystallinity and morphology of TiO2. Colloidal aqueous TiO2 photocatalysts are mainly being used in various photocatalytic reactions for organic pollutant degradation. The as-synthesized materials seem to have equivalent photocatalytic efficiency to the photocatalysts post-treated with thermal treatments and the commercial Evonik Aeroxide P25, which is produced by a high-temperature process. Indeed, as-prepared, the TiO2 photocatalysts present a high specific surface area and crystalline phases. Emerging applications are also referenced, such as elaborating catalysts for fuel cells, nanocomposite drug delivery systems, or the inkjet printing of microstructures. Only a few works have explored these new properties, giving a lot of potential avenues for studying this eco-friendly TiO2 synthesis method for innovative implementations.

Sign in / Sign up

Export Citation Format

Share Document