scholarly journals Physicochemical Characterization of Moroccan Phosphate and Coke of a Solid Combustible

2016 ◽  
Vol 8 (2) ◽  
pp. 72 ◽  
Author(s):  
Ikbal Bouatba ◽  
Mbarek Benchanaa ◽  
Mustapha El Hammioui ◽  
Latifa Bilali

<p>This paper concerns the study of the phosphate ore and a coke of solid combustible. The determination of their physicochemical characteristics and the study of their structural, textural and morphological aspects before and after thermal treatment are important and necessary for understanding of the reaction mechanisms and of the modelling of the processes of combustion and calcination.</p><p>The characterization of these materials was accomplished according to various experimental techniques such as: X-ray diffraction; infrared spectroscopy, scanning electron microscopy, porosimetry and the BET method. The results obtained show that the X-ray diffraction pattern of the coke presents only the crystalline phase of the graphite. The diffraction pattern of the raw phosphate as well as the crystallographic parameters at 25°C <br /> (a = 9.36 Å, c = 6.90 Å) are consistent with those given in the literature and indeed correspond to those of the crystal lattice of pure fluorapatite. The specific surface of natural phosphate is in the range of 13.36 m².g<sup>-1</sup> and that of the coke is 0.361 m².g<sup>-1</sup>. The total pore volume of the phosphate ore measured by the condensation of nitrogen adsorbed was 0.178 mL and the mean opening diameter of the pores is 0.029 m. The real density of the phosphate (2.96 g.cm<sup>-3</sup>) and that of the coke (1.36 g.cm<sup>-3</sup>), were determined using an ultra pycnometer. Morphological observation of the grain surface shows fairly homogenous areas and a porous structure in the phosphate ore. The coke grains show on the contrary a difference in the grain size and a non-porous structure.</p>

2012 ◽  
Vol 48 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Noely Camila Tavares Cavalcanti ◽  
Giovana Damasceno Sousa ◽  
Maria Alice Maciel Tabosa ◽  
José Lamartine Soares Sobrinho ◽  
Leila Bastos Leal ◽  
...  

The aim of this study was to characterize three batches of albendazole by pharmacopeial and complementary analytical techniques in order to establish more detailed specifications for the development of pharmaceutical forms. The ABZ01, ABZ02, and ABZ03 batches had melting points of 208 ºC, 208 ºC, and 209 ºC, respectively. X-ray diffraction revealed that all three batches showed crystalline behavior and the absence of polymorphism. Scanning electron microscopy showed that all the samples were crystals of different sizes with a strong tendency to aggregate. The samples were insoluble in water (5.07, 4.27, and 4.52 mg mL-1, respectively) and very slightly soluble in 0.1 M HCl (55.10, 56.90, and 61.70 mg mL-1, respectively) and additionally showed purities within the range specified by the Brazilian Pharmacopoeia 5th edition (F. Bras. V; 98% to 102%). The pharmacopeial assay method was not reproducible and some changes were necessary. The method was validated and showed to be selective, specific, linear, robust, precise, and accurate. From this characterization, we concluded that pharmacopeial techniques alone are not able to detect subtle differences in active pharmaceutical ingredients; therefore, the use of other complementary techniques is required to ensure strict quality control in the pharmaceutical industry.


2013 ◽  
Vol 28 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Jeffrey R. Deschamps

Chitin is a natural polysaccharide found in many diverse phyla and almost always occurs in association with protein. In this study the chitin polymer is characterized by X-ray diffraction from its naturally occurring unprocessed state through various steps used in the purification procedure. In addition, the effect of different treatments on the final product is examined. These studies show that native chitin has a characteristic diffraction pattern that is not altered by the mild treatments used to isolate relatively pure chitin. Chitins prepared from different sources exhibit the same characteristic diffraction pattern. In addition, chitin films prepared using non-degrading solvents retain most of the characteristic patterns. De-acylation of chitin to produce chitosan results in large changes to the diffraction pattern. To a very limited extent features present in the diffraction pattern of native chitin can be recovered by re-acylation of chitosan.


Author(s):  
R. Mis-Fernandez ◽  
J.A. Azamar-Barrios ◽  
C.R. Rios-Soberanis

This paper reports on the physicochemical characterization of solid powder obtained directly from wasted tires through pyrolysis and thermal shock process. Two different processes to reduce wasted tires were performed in order to acquire the residuals in powder to be characterized and compared.During this research, three phases were observed when pyrolysis was applied to rubber: the first one a solid black phase formed by organic and inorganic compounds such as zinc oxide (ZnO) and zinc sulphur (ZnS); secondly a gaseous phase containing hydrocarbons i.e. aromatic compounds and, finally, a liquid phase formed by heavy and light oils. By using X-ray diffraction technique, the relationship between temperature and the presence of inorganic compounds was determined varying the temperature of pyrolysis. In addition to X-ray diffraction, infrared spectroscopy, thermal analysis and scanning electron microscopy were used to fully characterize the samples. Comparing the results observed in both processes, it was found that thermal shock process presents some advantages over the pyrolytic, i.e. energy consume and solid black phase production; however, by pyrolytic egradation a powder richer in carbon compounds is obtained.


Author(s):  
Ottávio Carmignano ◽  
Sara Vieira ◽  
Ana Paula Teixeira ◽  
Fernando Lameiras ◽  
Paulo Roberto Brandão ◽  
...  

Currently, approximately 1.4 billion tons per year of iron ore tailing wastes (IOT) are generated, mainly in Australia, Brazil, and China. This work describes the characterization and application of two typical IOT, i.e., fine and coarse wastes. The physicochemical characterization of these IOT by different techniques such as XRF (X-ray fluorescence), XRD (X-ray diffraction), Mössbauer spectroscopy, and granulometry, indicates for the fine tailing a composition of Fe2O3/FeOOH (10-55%), SiO2 (18-65%) and Al2O3 (up to 15%) with particles of 6-40 μm, whereas the coarse tailing presents 40-150 μm particles with the composition of 8-48% Fe2O3/FeOOH, 30-90% SiO2 and Al2O3 (up to 20%). The main IOT applications discussed in this review are related to civil construction (aggregates for concrete, mortar, Portland cement additives), ceramic industry, geopolymer, synthesis of new materials such as zeolites, mesoporous silica, carbon nanotubes, adsorbents, catalysts for different reactions, in batteries and in fuel cells. It was also carried out an analysis of patents related to IOT applications and the main technological and market barriers that hinder the industrial and commercial uses of these wastes.


2020 ◽  
Vol 8 (4) ◽  
pp. 1258-1267

The objective of this work was the physicochemical characterization of a Moroccan natural clay from the Jorf Arfoud region (Lampert Coodinates: x = 595610, y = 101578) and its valorization in the elimination of organic pollutants (methyl orange MO and methylene blue MB) from aqueous solutions, with the adsorption technique on raw and calcined clay at 500°C. The clay was characterized by chemical analysis such as X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron microscopy (SEM). Crude and purified clays, consisting essentially of silica and alumina, are a characteristic property of phyllosilicates and also contain amounts of quartz, kaolinite and calcite as associated minerals. The experiments were performed after optimization of the parameters influencing the system, such as pH, adsorbent mass, initial dye concentration and temperature. The clays used absorb better the MB than MO, for an initial concentration of 10 mg/L and 20 mg/L respectively. Langmuir and Freundlich models of adsorption isotherms were applied to fit experimental equilibrium data. Results have showed that the adsorption of MB and MO followed very well the second order kinetic model on raw clay. The adsorption process was found to be exothermic in the case of MB. However, the adsorption of MO was endothermic.


2015 ◽  
Vol 70 (10) ◽  
pp. 719-725 ◽  
Author(s):  
Cristian Villa-Pérez ◽  
Isabel C. Ortega ◽  
Angélica M. Payán-Aristizábal ◽  
Gustavo Echeverría ◽  
Gloria C. Valencia-Uribe ◽  
...  

AbstractA new complex of Hg(II) with 6-methoxyquinoline (C10H9NO-6MQ) has been synthesized and characterized. The structure of the complex Hg(6MQ)Cl2 was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/c with a = 3.9139(3), b = 26.3400(2), c = 10.9090(9) Å, β = 89.833(6)°, V = 1124.6(1) Å3 and Z = 4 molecules per unit cell. The coordination geometry of the mercury(II) center can be described as a distorted square pyramid formed by one nitrogen atom of the 6MQ and four chlorine atoms. Fourier transform infrared, Raman and UV/Vis spectroscopic studies have been carried out to characterize the compound, using theoretical calculations for the assignment of the experimentally observed bands. The thermal behavior was investigated by thermogravimetric analysis. The quantum yield of singlet molecular oxygen production ΦΔ was measured with steady-state methods in ethanol, using 9,10-dimethylanthracene (DMA) as actinometer and Bengal rose as reference photosensitizer. The resultant singlet molecular oxygen was detected indirectly by photooxidation reactions of DMA. The luminescence properties have also been studied.


1994 ◽  
Vol 57 (9) ◽  
pp. 817-819
Author(s):  
ROBIN Y.-Y. CHIOU ◽  
WEN-CHING TZENG ◽  
KUO-FONG HUANG

Material with the appearance of mold mycelium was formed on salt stock prunes during drying. The moisture-free mycelium-like material consisted of 98.5 to 98.7% sodium chloride (NaCl), 1.67% organic matter and 0.165% acidity expressed as citric acid. X-ray diffraction analysis of the material revealed a diffraction pattern similar to that of NaCl. Formation of the material was dependent upon the efficiency and extent of drying. However, the material was not observed on deskinned salt stock prunes subjected to drying.


2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Giordano T. Paganoto ◽  
Deise M. Santos ◽  
Tereza C. S. Evangelista ◽  
Marco C. C. Guimarães ◽  
Maria Tereza W. D. Carneiro ◽  
...  

This paper is consisted in the synthesis of platinum-based electrocatalysts supported on carbon (Vulcan XC-72) and investigation of the addition of gallium in their physicochemical and electrochemical properties toward ethanol oxidation reaction (EOR). PtGa/C electrocatalysts were prepared through thermal decomposition of polymeric precursor method at a temperature of 350°C. Six different compositions were homemade: Pt50Ga50/C, Pt60Ga40/C, Pt70Ga30/C, Pt80Ga20/C, Pt90Ga10/C, and Pt100/C. These electrocatalysts were electrochemically characterized by cyclic voltammetry (CV), chronoamperometry (CA), chronopotentiometry (CP), and electrochemical impedance spectroscopy (EIS) in the presence and absence of ethanol 1.0 mol L−1. Thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM) were also carried out for a physicochemical characterization of those materials. XRD results showed the main peaks of face-centered cubic Pt. The particle sizes obtained from XRD and TEM analysis range from 7.2 nm to 12.9 nm. The CV results indicate behavior typical of Pt-based electrocatalysts in acid medium. The CV, EIS, and CA data reveal that the addition of up to 31% of gallium to the Pt highly improves catalytic activity on EOR response when compared to Pt100/C.


BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 4200-4211
Author(s):  
Ulises Carranza-Nuñez ◽  
Salomon Ramiro Vasquez-Garcia ◽  
Nelly Flores-Ramirez ◽  
Hamdy Ahmed Abdel-Gawwad ◽  
José Luis Rico ◽  
...  

Characterization of Ceiba aesculifolia (CA) fibers by various techniques is herein reported. The seed pods were collected, and the fibers surrounding the seeds were characterized or treated in an oven at 100 °C prior to characterization by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis coupled with a differential scanning calorimeter (TGA-DSC). The SEM micrographs showed that the natural material is comprised of tubes of external diameter of approximately 27 μm and a mean wall thickness of about 0.62 μm. The results also indicated that the tubes begin to decompose at approximately 220 °C.


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