Characterization of Industrial Wastes, Glass and Ceramic Wool

2012 ◽  
Vol 727-728 ◽  
pp. 1585-1590
Author(s):  
Neuza Evangelista ◽  
Jorge Alberto Soares Tenório ◽  
José Roberto Oliveira ◽  
Paulo R. Borges ◽  
Taiany Coura M. Ferreira
Keyword(s):  
Average Particle Size ◽  
Amorphous Structure ◽  
Glass Wool ◽  
Industrial Wastes ◽  
Average Particle ◽  
X Rays ◽  
Ceramic Fibers ◽  
High Concentrations ◽  
Reduction Of Energy Consumption ◽  
Superior Corrosion Resistance

Ceramic fibers are characterized by their light weight, high degree of purity, low heat storage, low thermal conductivity, thermal shock resistance and superior corrosion resistance in high-temperature environments. In addition, they can be produced extensively in substitution to all materials used in the coating of almost all heating equipment as well as contributing to the reduction of energy consumption. Such characteristics make them ideal in the coating of distributors, mufflers, heating ovens, among others, as highly demanded by the mining and metallurgical industries, among others. After use in the process of industrial production, generated waste will lose their insulation capacity and thus require safe disposal. The present work focuses specifically on ceramic and glass wools aiming at an evaluation of their recycling prospect of incorporation into cement mortars and concrete. This residues were pulverized and displayed ~30µm average particle size. The scan electronic microscopy (SEM) presented elongated, thin and straight particles, which is very different than flocular structure of cement. The X-rays diffraction revealed amorphous structure for glass wool and crystalline structure for ceramics wool. The chemical analysis showed high concentrations of Al2O3 and silica in both residues, with higher percentage of calcium oxide in glass wool.

Iodine-Rich Biocidal Reactive Materials

2013 ◽  
Vol 1521 ◽  
Author(s):  
Curtis E. Johnson ◽  
Kelvin T. Higa
Keyword(s):  
Average Particle Size ◽  
Amorphous Structure ◽  
Average Particle ◽  
Acid Solutions ◽  
Nitric Acid Solutions ◽  
Reactive Materials ◽  
Biocidal Products ◽  
Addition Rate ◽  
Mixed Material ◽  
Rapid Reaction

ABSTRACTThe objectives of this work are to prepare and characterize iodine-rich thermites and reactive materials for potential application in bio-agent defeat. Iodine-rich compositions were prepared using metal iodate oxidizers in combination with aluminum fuel. Higher iodine contents were achieved using iodine-rich additives, tetraiodoethylene and tin tetraiodide. Reactivity during rapid combustion was evaluated for both nanoscale and micron-scale materials. The nanoscale materials were evaluated directly using a spark-initiated pan dent test. The micron-scale materials were mixed with 50% of nano Al/MoO3 and also evaluated with the pan dent test. The results for the mixed material were shown to fit well to a linear combination of the expected dent for each component, based on a rapid reaction. Results of the pan dent test were used to down-select micron thermites for further testing. Bismuth iodate was synthesized by precipitation from nitric acid solutions. The average particle size was controlled by the addition rate, and sizes included 95 nm (amorphous structure), and 330 nm and 3 micron (both crystalline). Additional sizes were produced by ball milling the 3 micron material, giving 1 micron and 350 nm sizes. Fluoropolymers were included in some compositions to provide additional biocidal products, namely HF, that could be produced from reaction of AlF3 product with water.

Ceramic Membrane Made with Inorganic Residue

2017 ◽  
Vol 14 ◽  
pp. 60-85
Author(s):  
H. Lucena Lira ◽  
R.C. de Oliveira Lima ◽  
Iliana Oliveira Guimarães ◽  
G. Araújo Neves ◽  
R. Nóbrega Tavares ◽  
...  
Keyword(s):  
Pore Size ◽  
Water Flow ◽  
Ceramic Membrane ◽  
Average Particle Size ◽  
Ceramic Membranes ◽  
Industrial Wastes ◽  
Effluent Treatment ◽  
Average Particle ◽  
Flow Measurements ◽  
Mineralogical Characterization

Industrial wastes reuse becomes attractive to raw materials economy and to avoid environmental problems. The aim of this study is to develop and characterize tubular ceramic membranes using in their composition inorganic residues generated in the industries, such as, granite, alumina residue from calcination process and kaolin. Initially, it was performed the physical chemical and mineralogical characterization of the residues. Different formulations of ceramic masses have been studied with incorporation of residue, clay and additives for producing tubular membranes through the extrusion process. The membranes were characterized by SEM and flow measurements with distilled water. The membranes were applied to effluent treatment from textile and oil industry. The granite residue showed a high content of SiO2and Al2O3in its chemical composition and significant amount of iron and calcium oxides resulting from the granite processing. The granite residue presented average particle size of 13.98 µm. The residue from alumina process contain gibbsite and α-alumina, and average particles size of 15.68 µm. The residue from kaolin processing presented high content of quartz and alumina and average particles size of 29.0 µm. The tubular membrane produced with granite residue presented porosity from 17 to 30%, pores size in the range of 0.06 to 0.14µm and water flow from 10 (at 2 Bar) to 24 L/h.m2(at 4 Bar). These membranes retained 100% of indigo particles and was effective in the separation of indigo. The membrane prepared with alumina residue presented porosity close to 58% , pore size of 0.96 µm and water flow from 68 to 80 L/h.m2(at 2 Bar). These membranes were applied with successes in the separation of water from emulsion (100 ppm oil/water) with rejection above 96%. The membrane prepared with kaolin residue presented pore size from 0.16 to 0.22 µm, porosity from 41 to 44% and water flow from 53 to 70 L/h.m2. The ceramic membranes with industrial residues were successfully produced and applied in the treatment of industrial effluents.

scholarly journals Synthesis of submicronic α-alumina from local aluminum slags

2021 ◽  
pp. 53-53
Author(s):  
A. Benkhelif ◽  
M. Kolli ◽  
M. Hamidouche
Keyword(s):  
Particle Size ◽  
Extraction Efficiency ◽  
Average Particle Size ◽  
Alumina Powder ◽  
Average Particle ◽  
Ceramic Fibers ◽  
Transition Alumina ◽  
Future Studies ◽  
Refractory Ceramic ◽  
Precipitation Ph

In this study, a high valued product submicronic ?-alumina is successfully extracted from aluminum slags generated by the local aluminum industry. The extraction technique is based on the leaching of slags by H2SO4 followed by precipitation. The coarser aluminum-rich fractions of the slags are used in this study instead of the finer oxide-rich fractions that were commonly used in previous studies. The precipitation of the leached slags by NH4OH is controlled by zetameter in order to determine the optimal precipitation pH. Then, the obtained gel showing the higher precipitation rate and the finer particle size is calcined at 1200 ?C and characterized by XRF, XRD, FTIR, SEM, EDS and laser granulometry. Even without any pretreatment of slags, the XRF analysis reveals that a high purity and high extraction efficiency of 99.2% and 93.75% respectively can be achieved just at a leaching acid concentration of 15%. XRD spectrum shows that the produced alumina is a pure a-corundum, which is confirmed by FTIR spectrum showing only the Al-O bonds. The laser granulometry shows that the recovered powder exhibit a wide particle size distribution. It is between 50 nm and 20 ?m while the average particle size (d50) is about 400 nm. SEM observations reveal that the grains are in the form of submicronic whiskers. The above characteristics allow the obtained alumina powder in this study to be used in the usual applications of alumina such as refractory, ceramic fibers, abrasive, etc. The obtained powders may assume also applications as a thermally stable substitute for the commonly used transition alumina powders, which need further investigations in future studies.

The Method of Obtaining Amorphous Nanosized Silicon Dioxide from Rice Production Waste

2019 ◽  
Vol 23 (4) ◽  
pp. 30-35
Author(s):  
Ngo Hong Nghia ◽  
L.A. Zenitova ◽  
Le Quang Dien ◽  
Dao Ngoc Truyen
Keyword(s):  
Silicon Dioxide ◽  
Rice Husk ◽  
Black Liquor ◽  
Average Particle Size ◽  
Amorphous Structure ◽  
Rice Production ◽  
Raw Material ◽  
Production Waste ◽  
Average Particle ◽  
Naoh Solution

The method of using rice husk, which is a rice production waste, as a raw material for the production of silicon dioxide as an alternative to synthetic silicon dioxide – aerosil is considered. A low-energy process for extracting silicon dioxide and cellulose from the husk by alkaline digestion in an NaOH solution was proposed, followed by treating the black liquor with an acid solution and calcining the precipitate at 575 °C during 5 hours. The yield of inorganic products from rice husk is determined based on the ash content of the pulp. It was shown that the product obtained mainly consists of silicon dioxide (SiO2) of amorphous structure, has an average particle size of less than 100 nm, which makes it possible to characterize it as nanosilica. At the same time, silicon dioxide consists of 51.7 % silicon and 48.3% oxygen against theoretical amounts of 30.4 % silicon and 69.6 % oxygen, respectively. The output of silicon dioxide is 8.8 % by weight of rice husk. At the same time, the process allows to obtain another valuable nanocellulose product.

scholarly journals Promising Cathode Material for Lithium Power Sources LaFe0.5Cr0.5O3

2017 ◽  
Vol 18 (4) ◽  
pp. 444-448
Author(s):  
I. P. Yaremiy ◽  
M. L. Mokhnatskyi ◽  
L. V. Mokhnatska ◽  
S. I. Yaremiy ◽  
A. I. Kachmar
Keyword(s):  
Cathode Material ◽  
Sol Gel ◽  
Average Particle Size ◽  
Combustion Method ◽  
Test Material ◽  
Specific Power ◽  
Average Particle ◽  
X Rays ◽  
Power Sources ◽  
Average Size

Nanoscale powders of LaFe0.5Cr0.5O3 with perovskite structure were synthesized by the sol-gel combustion method in this work. From X-rays phase analysis obtained material consisted of one phase LaFe0.5Cr0.5O3 (space group P m -3 m). The average size of RCS of test material is 21 nm. The specific surface area is 14 m2/g. The average particle size is 63.7 nm by approximation that particles form is spherical. Nanoscale powders of LaFe0.5Cr0.5O3were tested as cathode material for lithium power sources. The cathode material demonstrates the specific power capacity of 571 A•h/kg when the discharge of the source is up to 0.5V.

scholarly journals Specific surface, crystalite size of AlB12-nano of products of interaction "BN-Al" in vacuum

Surface ◽  
2021 ◽  
Vol 13(28) ◽  
pp. 175-181
Author(s):  
V. A. Petrova ◽  
◽  
V. V. Garbuz ◽  
V. B. Muratov ◽  
M. V. Karpets ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Boron Carbide ◽  
Specific Surface ◽  
Liquid Aluminum ◽  
Average Particle Size ◽  
Weight Ratio ◽  
Shear Stresses ◽  
Average Particle ◽  
X Rays ◽  
Wide Range

Boron carbide (BC, B15-xCx B4C) has a unique combination of properties. This makes it a material for priority applications for a wide range of engineering solutions. The high melting point and heat resistance of the compound contribute to its use in refractory conditions. Due to its extreme abrasion resistance, B4C is used as an abrasive powder and coating. Due to its high hardness and low density, B15-xCx has ballistic characteristics. It is usually used in nuclear programs as an absorbent of neutron radiation Boron carbide ceramics (B15-xCx or BC) may lose strength and toughness due to the amorphization effect under high shear stresses. Aluminum dodecaboride AlB12 or B12Al, as well as boron carbide B12 [(CCC) x (CBC) 1-x] have common structural units B12 family of boron-icosahedral structures. The bond between icosahedrons is mainly due to atoms (Al, Si, O) or chains (CMC), where M is Al, Si, B, C. Doping BC powder with a small amount of AlB12, in cases of shock-shear stress, triggers the mechanism of "micro-cracking". Micro cracks and pores are formed in ceramics. The breakdown voltage decreases. AlB12 synthesis is associated with known difficulties. On the other hand. The production of metal-ceramic materials for several decades is associated with the interaction of liquid aluminum and boron nitride. The calculation of this reaction shows that it is exothermic. Avoiding oxidation in vacuum, the reaction occurs through the formation of aluminum nitride and aluminum dodeca-boride. In contrast to the liquid state, the process continues until the end, at conditional temperatures of evaporation of aluminum with slight changes in vacuum. The reaction product is a mixture of nanosized AlN/AlB12 powders with a weight ratio of 3/1 ready for baking without grinding. The acid-base properties of the nanosized powder mixture AlN + AlB12, the products of the interaction BN + Al in vacuum, which are used optionally, emit separate in pure phases of aluminum nitride and aluminum dodeca-boride. The yield of AlB12 is ~ 25%, boron reaches ~ 100%. The average particle size of the AlB12 powders according to TEM and ACS X-rays (area of coherent X-rays scattering), L (nm) is LTEM=110-150nm, LACS=51-70nm. The average specific surface area of the powder according to BET, TEM and ACS, SBET.m2/g=21,0-15,0; STEM.m2/g=21,4-15,4; SACS.m2/g=46,1-33,6; (at 1460 and 1640K, respectively).

Application of Amorphous Nanoparticle Fe-B Magnetic Fluid in Wastewater Treatment

NANO ◽  
2019 ◽  
Vol 14 (09) ◽  
pp. 1950119 ◽  
Author(s):  
Chuncheng Yang ◽  
Mengchun Yu ◽  
Xiuling Cao ◽  
Xiufang Bian
Keyword(s):  
Wastewater Treatment ◽  
Magnetic Fluid ◽  
Magnetic Particles ◽  
High Efficiency ◽  
Removal Rate ◽  
Average Particle Size ◽  
Oxygen Demand ◽  
Amorphous Structure ◽  
Average Particle ◽  
High Concentration

Amorphous magnetic particles demonstrate excellent comprehensive properties and outstanding characteristics for numerous applications. In this report, magnetic crystalline Fe3O4 and amorphous Fe-B nanoparticles were successfully synthesized and introduced to prepare water-based magnetic fluids. The Fe3O4 and Fe-B particles are homogeneous nanoparticles with an average particle size of [Formula: see text][Formula: see text]nm. The shape of Fe-B amorphous nanoparticles is regular. The saturation magnetizations of Fe-B and Fe3O4 particles are 74 emu/g and 69 emu/g. The use of crystalline Fe3O4 magnetic fluid and amorphous Fe-B magnetic fluid in advanced treatment of high concentration organic wastewater was presented. The removal rate of chemical oxygen demand by using the amorphous Fe-B magnetic fluid reached 96%, about 16% higher than that by using the Fe3O4 magnetic fluid. Moreover, compared with Fe3O4 magnetic fluid, the treatment results demonstrate that the decolorizing effect by using the amorphous Fe-B magnetic fluid was 20% higher. It has been found that the nano-size Fe-B particles in magnetic fluid with amorphous structure led to high efficiency of wastewater treatment due to the catalytic activity.

scholarly journals Microencapsulation of Vegetable Oil: Alternative Approaches Using Membrane Technology and Spray Drying

2017 ◽  
Vol 45 (2) ◽  
pp. 29-33 ◽  
Author(s):  
Krisztina Albert ◽  
Gyula Vatai ◽  
András Koris
Keyword(s):  
Spray Drying ◽  
Vegetable Oil ◽  
Membrane Fouling ◽  
Average Particle Size ◽  
Continuous Phase ◽  
Membrane Technology ◽  
Wall Material ◽  
Dispersed Phase ◽  
Average Particle ◽  
High Concentrations

Abstract Microencapsulation technology is a method that is widely used in the food industry. By comparing the latest encapsulation techniques, a significant number of publications concern membrane technology. The term “membrane- based encapsulation” entails that the first step of the technique is the preparation of emulsion with the help of microporous membranes. Generally, in microencapsulation technologies, the wall material is dissolved in a continuous phase and oil is dispersed within it. In the present investigation, a new method of preparing microcapsules composed of vegetable oil and maltodextrin was developed. In the first step, the wall material (maltodextrin) was dissolved in oil and considered as a dispersed phase, subsequently, it was introduced into a continuous phase (water) through a microporous membrane. A comparative study was conducted between conventional microencapsulation techniques and one developed in our laboratory. The average particle size of microcapsules prepared by our method is smaller than the size allowed by other methods. After encapsulation preparation, fine-tuned microcapsules were produced by spray drying. However, the main disadvantage of our proposed technology is rapid membrane fouling, because of high concentrations of solute in the dispersed phase. This problem can be eliminated by judicious and systematic investigations.

Enhanced catalytic activity of low-Pt content nanocatalysts supported on hollow carbon spheres for the ORR in alkaline media

MRS Advances ◽  
2020 ◽  
Vol 5 (57-58) ◽  
pp. 2961-2972
Author(s):  
P.C. Meléndez-González ◽  
E. Garza-Duran ◽  
J.C. Martínez-Loyola ◽  
P. Quintana-Owen ◽  
I.L. Alonso-Lemus ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Anion Exchange ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Alkaline Media ◽  
High Catalytic Activity ◽  
Average Particle ◽  
Carbon Spheres ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

In this work, low-Pt content nanocatalysts (≈ 5 wt. %) supported on Hollow Carbon Spheres (HCS) were synthesized by two routes: i) colloidal conventional polyol, and ii) surfactant-free Bromide Anion Exchange (BAE). The nanocatalysts were labelled as Pt/HCS-P and Pt/HCS-B for polyol and BAE, respectively. The physicochemical characterization of the nanocatalysts showed that by following both methods, a good control of chemical composition was achieved, obtaining in addition well dispersed nanoparticles of less than 3 nm TEM average particle size (d) on the HCS. Pt/HCS-B contained more Pt0 species than Pt/HCS-P, an effect of the synthesis method. In addition, the structure of the HCS remains more ordered after BAE synthesis, compared to polyol. Regarding the catalytic activity for the Oxygen Reduction Reaction (ORR) in 0.5 M KOH, Pt/HCS-P and Pt/HCS-B showed a similar performance in terms of current density (j) at 0.9 V vs. RHE than the benchmark commercial 20 wt. % Pt/C. However, Pt/HCS-P and Pt/HCS-B demonstrated a 6 and 5-fold increase in mass catalytic activity compared to Pt/C, respectively. A positive effect of the high specific surface area of the HCS and its interactions with metal nanoparticles and electrolyte, which promoted the mass transfer, increased the performance of Pt/HCS-P and Pt/HCS-B. The high catalytic activity showed by Pt/HCS-B and Pt/HCS-P for the ORR, even with a low-Pt content, make them promising cathode nanocatalysts for Anion Exchange Membrane Fuel Cells (AEMFC).

A New Method for Direct Determination of the Recoilless Fraction with Application to Magnetic Nanoparticles

2002 ◽  
Vol 721 ◽  
Author(s):  
Monica Sorescu
Keyword(s):  
Room Temperature ◽  
Average Particle Size ◽  
Direct Determination ◽  
Average Particle ◽  
Lattice Method ◽  
Recoilless Fraction ◽  
Single Room ◽  
Magnetite Particles ◽  
Physical Mixtures

AbstractWe propose a two-lattice method for direct determination of the recoilless fraction using a single room-temperature transmission Mössbauer measurement. The method is first demonstrated for the case of iron and metallic glass two-foil system and is next generalized for the case of physical mixtures of two powders. We further apply this method to determine the recoilless fraction of hematite and magnetite particles. Finally, we provide direct measurement of the recoilless fraction in nanohematite and nanomagnetite with an average particle size of 19 nm.

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