scholarly journals Mineral composition and commercial application feasibility of sericite ore in Ha Tinh Province

2020 ◽  
pp. 32-38
Author(s):  
T. I. Yushina ◽  
◽  
A. M. Dumov ◽  
Van Chon Nguyen ◽  
Thu Thuy Nguyen ◽  
...  
Keyword(s):  
Mineral Composition ◽  
Fine Particles ◽  
Economic Value ◽  
Analytical Techniques ◽  
Commercial Application ◽  
Uniform Structure ◽  
Silicate Mineral ◽  
Ore Processing ◽  
Finely Disperse ◽  
Size Of Particles

Sericite is a silicate mineral, a finely disperse and partly hydrated variety of muscovite. It is widely applied in many areas of engineering and production, and has a high economic value. Sericite has been produced and used in the world for a few hundred years. In Vietnam, a new-discovered sericite deposit holds commercial quality reserves. This article presents the studies into the mineral composition of sericite ore from Ha Tinh deposit using a set of the modern analytical techniques, which prove efficiency of the commercial-level production and processing of this ore. The integrated studies into material constitution of Ha Tinh sericite ore show the uniform structure of sericite and insignificant content of unwanted impurities. The size of sericite particles markedly differs from the size of other minerals in the initial ore. The content of quartz gradually increases with increasing size of ore particles, while the content of sericite gradually grows with decreasing size of particles. In particularly, in very fine particles (size less than 10 μm), the content of sericite is higher than in the initial ore by 2 times and reaches 70%, while the content of quartz is 4 times less than in the initial ore. Impurities feature nonuniform distribution and occur in some mineral grains such as apatite Ca5(PO4O)3, iron oxides and binding particles of solid solutions. During ore processing, impurities can be separated to waste, and it is possible to produce a marketable product in the form of a high quality sericite powder which meets the application standards of the porcelain, ceramic, resin and other industries. Thus, Hà Tĩnh sericite ore can be converted into valued products to be used in many various industries.

Thorium in crandallite-group minerals: an example from a Devonian bauxite deposit, Timan, Russia

2004 ◽  
Vol 68 (3) ◽  
pp. 489-497 ◽  
Author(s):  
L. E. Mordberg
Keyword(s):  
Crystal Lattice ◽  
Radiation Damage ◽  
Mineral Composition ◽  
Bauxite Deposit ◽  
Weathering Profile ◽  
Silicate Mineral ◽  
Fe Content ◽  
Very High ◽  
Type Substitution ◽  
Simplified Formula

AbstractA Th-rich mineral of the crandallite group has been investigated from the weathering profile of the Schugorsk bauxite deposit, Timan, Russia. It occurs within thin (up to 0.5 mm) organic-rich veinlets together with ‘leucoxene’ in the form of small shapeless grains which vary in size from 1—2 mm to 60—70 mm. Rare grains disseminated among boehmite crystals were also found. Microprobe analyses determined that the ThO2 content can be as high as 18 wt.%. The mineral composition is intermediate between crandallite CaAl3H(PO4)2(OH)6, goyazite SrAl3H(PO4)2(OH)6, Th-crandallite and svanbergite SrAl3PO4SO4(OH)6 in the beudantite group.Comparatively high contents of Fe and Si and a very high positive Th and Fe content correlation (r = +0.98) suggest that the formula of the hypothetical Th-bearing end-member is ThFe3(PO4,SiO4)2(OH)6 with Th and Si substituting for REE and Prespectively (woodhouseite-type substitution). Another possible substitution is Th4+ + Ca2+ ⇋ 2REE3+ (florencite-type). A deficiency of cations in the X site can be explained by either the presence of carbon, undetectable by microprobe, in the crystal lattice or a lack of X-site cations due to radiation damage induced by Th. Some excess of cations in the B site (Al and Fe3+) can be explained by the presence of very small boehmite and hematite inclusions on the crandallite grain surfaces. Th-rich crandallite may be the result of alteration of an unidentified silicate mineral from the parent rock with a composition close to the simplified formula Fe2+ThSiO4(OH)2.

Features of the long-term dynamics of heart rate variability among workers of a potash ore processing enterprise

2021 ◽  
Vol 61 (7) ◽  
pp. 442-450
Author(s):  
Alexandr E. Nosov ◽  
Nina V. Zaitseva ◽  
Vitalii G. Kostarev ◽  
Julia A. Ivashova ◽  
Maksim A. Savinkov ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Significant Relationship ◽  
Work Experience ◽  
Fine Particles ◽  
Comparison Group ◽  
Stress Index ◽  
Observation Group ◽  
Ore Processing ◽  
Processing Enterprise

Introduction. Currently, the violation of heart rate variability as one of the main pathogenetic mechanisms of the damaging effect of pollutants, associated effects on the cardiovascular system. The study aims to explore the dynamics of the influence of the autonomic nervous system (ANS) on heart rate variability (HRV) in workers of a potassium ore processing enterprise exposed to industrial pollutants (fine fractions of potassium chloride dust, formaldehyde, hexane, heptane) with an assessment of changes in dependence from work experience, establishment of cause-and-effect relationships of violations of heart rate variability with exposure to chemical compounds. Materials and methods. The object of the study was 140 employees of a potash ore processing enterprise, assigned to the observation group, and 76 employees of the administrative and technical apparatus, who made up the comparison group. Samples were taken from the air of the working medium for the content of saturated hydrocarbons (hexane, heptane), the vapors of formhehyde were considered, and the presence of fine particles PM2.5 and PM10 was established. Investigation of biological media (blood, urine) of workers at the enterprise determination of formaldehyde in blood, hexane and heptane in urine. Evaluation of heart rate variability was carried out on a computer electrocardiograph "Poli-Spectr-8/EX" using a cardiorhythmographic program using the method of time analysis, variation pulsometry and spectral analysis. Results. The concentration of fine particles in the air at the workplaces of the observation group was 12-111 times higher for PM2.5, and 5.6-74.6 times higher for PM10 than for the work places of the comparison group. The concentration of formaldehyde, hexane and heptane in the air did not exceed hygienic standards. In the observation group relative to the comparison group, formaldehyde blood was 1.5 times (p<0.001), in the urine of hexane - 1.2 times (p=0.011), heptane - 1.3 times (p=0.046). It was found that with an experience of up to 10 years, formaldehyde in the blood of workers in the observation group was 1.4 times higher than that in the comparison group (p=0.011), with an experience of more than 10 years - 1.7 times (p=0.005). In the urine of workers in the observation group with work experience of up to 10 years, an excess of 1.3 (p=0.026) relative to the comparison group of hexane was found. HRV data analysis. With damage to the length of service in the observation group, there was a significant decrease in the temporal analysis indicators (SDNN, ms, RMSSD, ms, pNN50, %, CV, %), while in the comparison group, only the CV, % decrease was statistically significant; the values of IN conventional units, AMo, % significantly increased (p=0.03 and p=0.003, respectively). A statistically significant relationship was established between the likelihood of an increase depending on the content of heptane in urine (b0=0.22; b1=10.6; F=21.5; R2=0.09; p=0.0001) and formaldehyde in the blood (b0=0.02; b1=6.55; F=69.6; R2=0.25; p=0.0001) in the surveyed workers. Conclusions. Activation of central ergotropic and humoral-metabolic mechanisms, a tendency towards a decrease in parasympathetic influences. The method of logistic regression analysis established a statistically significant relationship between the probability of an increase in the stress index depending on the heptane content in the blood of the surveyed suppliers.

scholarly journals The Effects of Calcination on Mineral Composition and Physical Properties of Limestones and Oyster Shells Derived from Different Sources

2021 ◽  
Vol 11 (4) ◽  
pp. 578-586
Author(s):  
Khalil . ◽  
Ridho Kurniawan Rusli ◽  
Andri .
Keyword(s):  
Physical Properties ◽  
Mineral Composition ◽  
Fine Particles ◽  
Oyster Shell ◽  
Angle Of Repose ◽  
Chemical Compositions ◽  
Mineral Concentration ◽  
Tapped Density ◽  
Different Sources ◽  
Decomposition Properties

Limestones and oyster shells are normally used in raw or roasted meal form in the livestock diet. Calcination is intended to improve the mineral concentration and physical characteristics of limestones and oyster shells which vary based on different chemical compositions, textures, and impurities of their types and habitats. The present research aimed to study the effects of calcination on mineral composition and the physical properties of limestones and oyster derived from various sources. Limestone samples from three local limestone mining and oyster shell samples from three shellfish species were calcined by burning at a temperature of 800-1000°C. The calcined products were analyzed for mineral content (Ca, P, Mg, Cu, Zn, and Mn), physical properties (bulk density, tapped density, specific density, and angle of repose), and particle size. Results indicated that calcination had no significant effect on Ca and P concentrations but reduced micro mineral concentration. Limestones had a higher Mg concentration than that of oyster shells, and calcination increased Mg concentration. Calcined oyster shells had higher densities, percentages of fine particles, and lower angles of response. The results suggested that the type of limestones and oyster shells could determine their thermal decomposition properties.

Reconstructing the Firing and Pigment Processing Technologies of Corinthian Polychrome Ceramics, 8-6th Centuries B.C.E.

MRS Advances ◽  
2017 ◽  
Vol 2 (35-36) ◽  
pp. 1889-1909
Author(s):  
Catherine Klesner ◽  
Jay A. Stephens ◽  
Emilio Rodriguez-Alvarez ◽  
Pamela B. Vandiver
Keyword(s):  
Firing Temperature ◽  
Raw Materials ◽  
Economic Value ◽  
Analytical Techniques ◽  
Ceramic Technology ◽  
Raw Material ◽  
Detailed Knowledge ◽  
Material Particle ◽  
Processing Technologies ◽  
Firing Range

ABSTRACTDecorative, polychrome ceramics from Corinth, Greece, produced during the 8th-6th centuries B.C.E. were luxury goods widely traded throughout Greece and the Mediterranean. Corinthian pottery is the first 5-color polychrome ceramic technology, having slip-glazes in distinctive white, black, red, yellow, and purple colors, and in a variety of surface finishes from glossy, to semi-matte, to matte. The firing temperature range, 925-1075°C, was determined experimentally to be to be higher than previously reported, similar to the Corinthian amphorae and other ceramic products. This firing range is higher than that of the better known, more prestigious Athenian Black-figure and Red-figure ceramics. In this study three examples of Corinthian and one example of Athenian Black-figure ceramics from the Marie Farnsworth collection at the University of Arizona were tested and compared to thirteen clays from Corinth. Analytical techniques included Fourier-transform infrared spectroscopy (FTIR), scanning-electron microscopy with energy-dispersive spectroscopy (SEM-EDS), micro-Raman spectroscopy, and wavelength-dispersive electron microprobe (EPMA with BSE-SEM).Artisans in Corinthian workshops experimented to change the colors of the slips by varying the type and amount of iron-rich raw material, as well as the composition of the clay used as a binder and the amount of flux used as a sintering aid to promote glass formation. Corinthian artisans developed not only different recipes to produce the various colors, but also they were able to control raw-material particle size and composition to produce variations in surface luster (matte, semi-matte and glossy). This research suggests that Corinthian polychrome-slip technology was based on careful control of particle processing, of compositional control of raw materials and their admixtures, and of firing temperature. The behavior or practice of adding different ratios of pigments and glass-forming fluxes to form various optical effects implies a detailed knowledge of what happens when these are heated and fired. This is a process of experimentation focused on developing a distinctive craft practice, which produced a distinctive and highly valued material. The Corinthians developed a more complex, easily recognizable, and culturally distinctive ceramic technology that was intentionally established as a cultural brand, and probably as a luxury brand of high socio-economic value. This research deepens our understanding of the complex pigment processing and firing technologies employed in the production of Corinthian ceramics.

Effect of Storage in Flour and of Particle Size on the Bioavailability of Elemental Iron Powders for Rats and Humans

1977 ◽  
Vol 60 (4) ◽  
pp. 759-765 ◽  
Author(s):  
Ramesh S Verma ◽  
Ilary Motzok ◽  
Shy-Show Chen ◽  
Jaroslava Rasper ◽  
Henry U Ross
Keyword(s):  
Particle Size ◽  
Carbonyl Iron ◽  
Fine Particles ◽  
Iron Absorption ◽  
Iron Supplement ◽  
Electrolytic Iron ◽  
Biological Value ◽  
Iron Powders ◽  
Elemental Iron ◽  
Size Of Particles

Abstract Elemental iron powders produced by different processes were separated by nitrogen elutriation into fractions based on particle size. The fractions containing fine particles (7–10 μm) of electrolytic iron, hydrogen (H2)- and carbon monoxide (CO)-reduced iron, and the whole sample of carbonyl iron (92% &lt;11 μm) were blended into freshly milled wheat flour and stored at about 21°C. Storing the enriched flour up to 9 months had no effect on the relative biological value (RBV) of iron for rats from each type of iron supplement. Baking bread with flour containing electrolytic, H2-reduced, and carbonyl iron after storage for 10 months also had no effect on the RBV of the iron powders. There was no change in the RBV of iron for rats from flour enriched with electrolytic iron (200 mg/kg) and ascorbic acid (200 and 1665 mg/kg flour) after storage for 1 week and 3 months. The decreases in RBV due to increase in size of particles (7–10 vs. 20–26 μm) were significant for H2-reduced iron and CO-reduced iron but not for electrolytic iron and carbonyl iron. The RBVs of elemental iron powders for rats were similar to the values obtained with humans, based on iron absorption after an overnight fast.

scholarly journals KAJIAN POTENSI PERENCANAAN WILAYAH KOTA BINJAI SUMATERA UTARA

2021 ◽  
Vol 1 (1) ◽  
pp. 36
Author(s):  
Yuanita F.D Sidabutar ◽  
Edi Indera
Keyword(s):  
Statistical Analysis ◽  
Regional Planning ◽  
Economic Value ◽  
Analytical Techniques ◽  
Study Data ◽  
Border Area ◽  
City Area ◽  
Potential Development ◽  
Survey Results ◽  
The City

The potential of Binjai City is the border area of Medan City and areas outside Medan City (Aceh, Langkat, Stabad and others). The city of Binjai has 5 sub-districts with 37 villages. Located approximately 25 km from the center of Medan City, Binjai City is a city that has the potential to become a transit city with its boundaries that can reach many areas so that transportation facilities must be developed as much as possible. Objectives 1) Understand information on the potential of the Binjai City area. 2) Knowing the condition of the potential development of Binjai City. 3) Informing the development of the potential of the Binjai City area. Binjai City. The study data on the potential for regional planning of Binjai City has 1) Binjai City has culinary potential 2) Binjai City has transit terminal facilities, 3) Binjai City has tourism places in several villages. The results of this study were carried out using analytical techniques from survey results to the field in the form of analysis of the condition of regional potential, and data from the distribution of questionnaires in the form of percentage statistical analysis results. And also obtained the concept of thinking for how to increase the economic value of Binjai City.

scholarly journals Synthesis, Characterization and Methyl Orange Degradation Activity of Ti-Al Oxides Nanomaterial

2019 ◽  
Vol 16 (3) ◽  
pp. 252-260 ◽  
Author(s):  
Buzuayehu Abebe ◽  
H C Ananda Murthy
Keyword(s):  
Methyl Orange ◽  
Analytical Techniques ◽  
Reaction Rate Constant ◽  
Degradation Efficiency ◽  
Impregnation Method ◽  
Methyl Orange Degradation ◽  
Ft Ir ◽  
Degradation Activity ◽  
Size Of Particles ◽  
Xrd Patterns

The present work reports the synthesis of Ti-Al Oxides (TAOs) nanomaterial by an organic solvent-free impregnation method. The as-prepared products were studied by XRD, SEM-EDAX, UV-Vis, and FT-IR analytical techniques. XRD patterns revealed the fact that both TiO2 (TO)and TAOs exhibited almost similar peaks with the exception to minor peak difference in width and height which could be attributed to the alteration in the size of particles. At the calcination temperature of 500 oC, the absence of peaks for Al2O3 (AO) in the TAOs XRD pattern indicates the amorphous nature of AO. However, the appearance of Ti, Al, and O on EDAX and redshift on UV-Vis spectra confirm the successful impregnation of AO on TO. The pollutant degradation ability of TAOs photocatalyst was tested on methyl orange (MO) dye. Compared to pure TO, TAO composite has greater degradation efficiency. However, as the percentage of AO increases the degradation efficiency decreases. The conducted Langmuir model test was found to fit well for the photocatalytic reaction process following first-order reaction kinetics. Comparing the values for kinetics constant with earlier work, this work showed good MO degradation efficiency with reaction rate constant (k) values of 0.023.

The Analyses of Anthropogenic Atmospheric Particulates by EM

1990 ◽  
Vol 48 (2) ◽  
pp. 547-547
Author(s):  
Philip A. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Particles ◽  
Analytical Techniques ◽  
Bulk Sample ◽  
Airborne Particulates ◽  
Discrete Particle ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
Scanning Electron

This presentation will summarize fourteen years of research on the physical and chemical nature of particulates suspended in the earths atmosphere utilizing scanning electron microscopy and, to a lesser extent, transmission electron microscopy. Topics to be discussed include (1) the rationale for using electron microscopy to study airborne particulates, (2) methods for collecting airborne particulates, (3) methods of analysis and (4) a summary of results. Examples will demonstrate how conclusions about the nature and source of collected particles can differ between bulk sample analyses and discrete particle analyses. Without the input from discrete particle analyses, bulk analytical techniques may produce serious errors in the apportionment of airborne particulates to specific sources.The scanning electron microscope (SEM) and transmission electron microscopy (TEM) have proven themselves to be the preferred instruments to use in the study of discrete fine particles because they permit sufficient resolution and analytical capabilities to examine the structure and chemistry of individual particles less than a few micrometers in diameter.

scholarly journals Facile Synthesis of Magnetic Activated Carbon Composite for Arsenic Adsorption

2019 ◽  
Vol 15 (2) ◽  
pp. 71-78
Author(s):  
Bivek Karki ◽  
Pragya Pandey ◽  
Rinita Rajbhandari ◽  
Sahira Joshi ◽  
Agni Raj Koirala ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Iron Oxide ◽  
Analytical Techniques ◽  
Carbon Composite ◽  
Commercial Application ◽  
Arsenic Content ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Arsenic Adsorption ◽  
X Ray ◽  
Removal Of Arsenic

Porous activated carbon (AC) and magnetic iron oxide nanoparticles (NPs) are widely used for the removal of arsenic from water body. Fabrication of composite material of iron oxide NPs on the surface of porous AC can further enhance this activity for commercial application. In this research, a magnetic AC composite for arsenic adsorption was prepared by facile hydrothermal treatment of aqueous solution containing activated carbon obtained from lapsi seed stone, iron(II) chloride, polyvinylpyrrolidone (PVP) and ethanol. Several analytical techniques such as scanning electron microscopy (SEM), energy dispersive x-ray (EDX), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of magnetite (Fe3O4) nanoparticles on the surface of porous AC. The prepared materials were accessed for their arsenic adsorption capacity using arsenic (III) trioxide solution and found that composite Fe2O3/AC can remove the arsenic from water far more effectively than activated carbon alone. For 0.5 g/ltr loading of composite sample with contract time of 5 hours, the arsenic content was significantly reduced, which shows that as-fabricated composite can be used potentially for water treatment.

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