scholarly journals Pyrophyllite: An Economic Mineral for Different Industrial Applications

2021 ◽  
Vol 11 (23) ◽  
pp. 11357
Author(s):  
Maaz A. Ali ◽  
Hussin A. M. Ahmed ◽  
Haitham M. Ahmed ◽  
Mohammed Hefni
Keyword(s):  
Electrical Conductivity ◽  
Market Value ◽  
Industrial Applications ◽  
Al2o3 Content ◽  
High Alumina ◽  
Low Grade ◽  
Molten Metals ◽  
Chemical Inertness ◽  
Refractory Ceramic ◽  
Economical Alternative

Pyrophyllite (Al2Si4O10(OH)2) is a phyllosilicate often associated with quartz, mica, kaolinite, epidote, and rutile minerals. In its pure state, pyrophyllite exhibits unique properties such as low thermal and electrical conductivity, high refractive behavior, low expansion coefficient, chemical inertness, and high resistance to corrosion by molten metals and gases. These properties make it desirable in different industries such as refractory; ceramic, fiberglass, and cosmetic industries; as filler in the paper, plastic, paint, and pesticide industries; as soil conditioner in the fertilizer industry; and as a dusting agent in the rubber and roofing industries. Pyrophyllite can also serve as an economical alternative in many industrial applications to different minerals as kaolinite, talc, and feldspar. To increase its market value, pyrophyllite must have high alumina (Al2O3) content, remain free of any impurities, and possess as much whiteness as possible. This paper presented a review of pyrophyllite’s industrial applications, its important exploitable properties, and the specifications required for its use in industry. It also presents the most effective and economical techniques for enriching low-grade pyrophyllite ores to make them suitable for various industrial applications.

Electro-conductively deposited carbon fibers for power controllable heating elements

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26998-27002 ◽  
Author(s):  
Chang Hyo Kim ◽  
Moo Sung Kim ◽  
Yoong Ahm Kim ◽  
Kap Seung Yang ◽  
Seung Jo Baek ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Carbon Fibers ◽  
Industrial Applications ◽  
Excellent Thermal Stability

Carbon fibers are considered as one of the promising heating elements in various industrial applications because of their excellent thermal stability and electrical conductivity.

On Electrical Conductivity Measurements of Molten Metals by Inductive Technique

2004 ◽  
Vol 126 (3) ◽  
pp. 468-470 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Mihai Dupac ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Electrical Conductivity ◽  
Fluid Flow ◽  
External Magnetic Field ◽  
Electric Conductivity ◽  
Molten Metals ◽  
Conductivity Measurements ◽  
Permanent Magnetic Field ◽  
Rotating Liquid

In this paper, we propose a new relationship between the opposing mechanical torque and the electric conductivity of a rotating liquid specimen in a permanent external magnetic field of constant induction, which includes the effect of fluid flow. The proposed relationship was applied to describe the experimental data for a conductive specimens rotating in a permanent magnetic field.

Fluid Flow Effect in Electrical Conductivity Measurements of Molten Metals by Inductive Technique

2002 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Mihai Dupac ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Electrical Conductivity ◽  
Fluid Flow ◽  
External Magnetic Field ◽  
Electric Conductivity ◽  
Molten Metals ◽  
Conductivity Measurements ◽  
Permanent Magnetic Field ◽  
Rotating Liquid

In this paper we propose a new relationship between the opposing mechanical torque and the electric conductivity of a rotating liquid specimen in a permanent external magnetic field of constant induction, which includes the effect of fluid flow. The proposed relationship was applied to describe the experimental data for a conductive specimen rotating in a permanent magnetic field.

scholarly journals Segregated network polymer/carbon nanotubes composites

2004 ◽  
Vol 2 (2) ◽  
pp. 363-370 ◽  
Author(s):  
A. Mierczynska ◽  
J. Friedrich ◽  
H. Maneck ◽  
G. Boiteux ◽  
J. Jeszka
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Network Formation ◽  
Processing Parameters ◽  
Low Grade ◽  
Single Walled Carbon ◽  
Conductive Composites ◽  
Grade Material

AbstractIn this work we present the preparation of conductive polyethylene/carbon nanotube composites based on the segregated network concept. Attention has been focused on the effect of decreasing the amount of filler necessary to achieve low resistivity. Using high- and low-grade single-walled carbon nanotube materials we obtained conductive composites with a low percolation threshold of 0.5 wt.% for high-grade nanotubes, about 1 wt% for commercial nanotubes and 1.5 wt% for low-grade material. The higher percolation threshold for low-grade material is related to low effectiveness of other carbon fractions in the network formation. The electrical conductivity was measured as a function of the single-walled carbon nanotubes content in the polymer matrix and as a function of temperature. It was also found that processing parameters significantly influenced the electrical conductivity of the composites. Raman spectroscopy was applied to study single wall nanotubes in the conductive composites.

Experimental Study on Flotation of Copper Sulfides in Yunnan Province

2014 ◽  
Vol 1010-1012 ◽  
pp. 1630-1635
Author(s):  
Jian Gang Ku ◽  
Hui Huang Chen ◽  
Wen Yuan Liu
Keyword(s):  
Experimental Study ◽  
Yunnan Province ◽  
Industrial Applications ◽  
Low Grade ◽  
Copper Ore ◽  
Copper Sulfides ◽  
Fine Grained ◽  
Concentrate Grade ◽  
Combination Mode ◽  
Grade Index

The copper ore, which has fine-grained nature and differences in the degree of mineral dissemination, is a kind of low grade sulfide minerals. Tests indicate that not only the grinding fineness but also the combination mode of depressants is one of the most important factors to improve the concentrate grade index. Additionally, according to tests conducted with dosage of lime, the rougher flotation should be operated at a pH of 11. Furthermore, all the depressants used were effective to increase the concentrate grade. By the closed-circuit micro-flotation experiment, satisfied grade index (18.7%Cu with 81% recovery) of the final concentrate was achieved, which could provide reference in industrial applications.

Thermodynamics and Transport Properties

2021 ◽  
pp. 72-181
Author(s):  
Thorvald Abel Engh ◽  
Geoffrey K. Sigworth ◽  
Anne Kvithyld
Keyword(s):  
Electrical Conductivity ◽  
Surface Tension ◽  
High Temperature ◽  
Physical Properties ◽  
Transport Properties ◽  
Thermochemical Data ◽  
Molten Metals ◽  
Free Energies ◽  
Interaction Coefficients ◽  
Chemical Equilibria

The fundamentals of thermodynamics are reviewed, focusing on the chemistry of high-temperature metals, oxides (slags), and salts. Thermochemical data are provided for important molten metals: the free energies of solution of alloy elements, and interaction coefficients. Standard free energies of reactions are also provided, so the reader may calculate important chemical equilibria. Example calculations are provided for the deoxidation of steel. The removal of sulfur and phosphorus are also described. The second half of the chapter considers fundamental aspects of important physical properties: viscosity, surface tension, diffusion, and thermal and electrical conductivity.

Study of Aging Heat Treatment Parameters for 7050 and 7075 Aluminum Alloys

2020 ◽  
Author(s):  
Sagil James ◽  
Ambarneil Roy
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Industrial Applications ◽  
Al Alloys ◽  
Time Parameter ◽  
Fatigue Properties ◽  
Operational Parameters ◽  
Grain Flow ◽  
Engineering Industries

Abstract Among the different commercially used Aluminum (Al) alloys, the 7000 series offers some of the highest mechanical properties making them the material of choice for several critical engineering applications. These Al alloys often required to undergo a heat treatment (HT) process to enhance their mechanical and metallurgical properties to the desired levels. Currently, there is a growing need to find the optimal operational parameters for the HT process of Al 7000 series alloys. The operators have to resort to a start/stop approach, while intermittently evaluating and testing the mechanical properties until the desired level is reached. Among the various steps, aging is the final and often the longest step in the HT process. Consequently, the age soak time parameter needs to be narrowed to the smallest possible operating range for industrial applications. This study aims to experimentally optimize the age soak time of Al 7000 series alloys (7050-T74 and 7075-T73) by measuring its hardness, electrical conductivity (EC), fatigue properties. The study found that the optimal age soak times for 7050-T74 and 7075-T73 Al alloys are between 24–27 hours and 22–24 hours, respectively. The results of the study are subsequently confirmed using the grain flow and grain direction analysis. The results of this study are crucial in extending the applications of Al 7000 series alloys in several critical engineering industries.

Relationship of the s1-elements halogenides melts specific electric conductivity with alkali metals specific electric conductivity

2019 ◽  
Vol 60 (12) ◽  
pp. 116-124
Author(s):  
Ivan K. Garkushin ◽  
◽  
Olga V. Lavrenteva ◽  
Yana A. Andreeva ◽  
◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electric Conductivity ◽  
Alkali Metals ◽  
Analytical Description ◽  
Specific Electrical Conductivity ◽  
Molten Metals ◽  
Specific Electric Conductivity ◽  
Metal Melts ◽  
Relationship Of ◽  
The Relationship

The paper presents an analytical description of the relationship of the specific electrical conductivity æ of individual alkali metals haloganides melts (MHal) (M – Li, Na, K, Rb, Cs, Fr; Hal – F, Cl, Br, I) and the specific electrical conductivity æ(M) of alkali metal melts for temperatures (Тпл + n) (Tпл – melting temperature K; n = 5, 10, 50, 75, 100, 150, 200° higher melting temperatures of MHal and metals) and the specific electrical conductivity of alkali metals at standard temperature using M.Kh. Karapetyans comparative methods. The relationship of properties æ(MHal при Тпл+n) = f(æ(MHal при Тпл+5)), æ(FrHalТпл+n) = f(æ(FrHalТпл+5°)) is described in the "property-property" coordinates. A comparative analysis of the specific electrical conductivity values of francium haloganides melts obtained by the proposed methods was carried out. The possibility of calculating the electrical conductivity of molten salts from the electrical conductivity of molten metals is shown. It is shown that the equation æ(MHal)0.5 = a + bæ(M)1.5 can be used to calculate the specific electrical conductivity of francium haloganides melts. The calculation of the specific electrical conductivity using various equations shows the consistency of the numerical values obtained.

scholarly journals Properties of TiN and TiN Deposited by CVD on Graphite for Pyrochemical Applications

1997 ◽  
Vol 495 ◽  
Author(s):  
P. S. Maiya ◽  
B. M. Moon
Keyword(s):  
Mechanical Properties ◽  
Chemical Vapor ◽  
High Density ◽  
Graphite Substrate ◽  
Molten Metals ◽  
Thermal Expansion Coefficients ◽  
Chemical Inertness ◽  
Liquid Metal Alloy ◽  
Powder Characteristics ◽  
Pull Tests

ABSTRACTHigh-density TiN (>098% of theoretical) has been prepared by hot pressing TiN powder with 2–4 wt.% Li2CO3 at temperatures between 1150–1550°C and pressures of ≈40–50 MPa. The Li2CO3 served as a fugitive sintering aid, enabling attainment of high density at low temperatures without adversely affecting the inherently good properties. Variation in processing variables and TiN powder characteristics resulted in material with various porosities. Measurement of mechanical properties such as flexural strength and fracture toughness showed that the high-density material has mechanical properties that are superior to those of several oxide ceramics. We have also quantified the effects of porosity on mechanical properties. In addition, adhesion and chemical stability tests were used to investigate graphite coated with TiN by chemical vapor deposition (CVD). Pin-pull tests were used to determine coating adhesion and failure stresses were analyzed by Weibull statistics. All pin-pull tests resulted in fracture of the graphite substrate, rather than separation at the TiN/graphite interface. The data showed a good fit to the two-parameter Weibull expression, with a failure strength of 16.4 MPa and Weibull modulus of 9.3. Both the high-density TiN and the TiN coating on the graphite were exposed to a corrosive molten salt CaCl2-7 wt.% CaO and a liquid metal alloy (Zn-10 wt.% Mg) at 800°C for 168 h to determine chemical interactions. No reaction was detected by scanning electron microscopy (SEM) or energy-dispersive X-ray (EDX) analysis. Thus, graphite coated with TiN by CVD combines the thermodynamic stability of TiN when exposed to reactive molten metals and salts, with the excellent machinability of graphite, and hence is promising for use in container vessels for pyrochemical processing of certain rare-earth and nuclear metals, where chemical inertness and good matching of thermal expansion coefficients are required.

scholarly journals Complex Electrical Conductivity of Biotite and Muscovite Micas at Elevated Temperatures: A Comparative Study

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3513
Author(s):  
Vassilios Saltas ◽  
Despoina Pentari ◽  
Filippos Vallianatos
Keyword(s):  
Electrical Conductivity ◽  
Elevated Temperatures ◽  
Small Polaron ◽  
Complex Impedance ◽  
Bound Water ◽  
Data Representation ◽  
Industrial Applications ◽  
Mechanical And Thermal Properties ◽  
Wide Range ◽  
Complex Electrical Conductivity

The unique physicochemical, electrical, mechanical, and thermal properties of micas make them suitable for a wide range of industrial applications, and thus, the interest for these kind of hydrous aluminosilicate minerals is still persistent, not only from a practical but also from a scientific point of view. In the present work, complex impedance spectroscopy measurements were carried out in muscovite and biotite micas, perpendicular to their cleavage planes, over a broad range of frequencies (10−2 Hz to 106 Hz) and temperatures (473–1173 K) that have not been measured so far. Different formalisms of data representation were used, namely, Cole-Cole plots of complex impedance, complex electrical conductivity and electric modulus to analyze the electrical behavior of micas and the electrical signatures of the dehydration/dehydroxylation processes. Our results suggest that ac-conductivity is affected by the structural hydroxyls and the different concentrations of transition metals (Fe, Ti and Mg) in biotite and muscovite micas. The estimated activation energies, i.e., 0.33–0.83 eV for biotite and 0.69–1.92 eV for muscovite, were attributed to proton and small polaron conduction, due to the bound water and different oxidation states of Fe.

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