scholarly journals PROSPECTS FOR THE INTEGRATED USE OF SLAG WASTES FROM FERROCHROME PRODUCTION FOR HEAT-RESISTANT MATERIALS

2020 ◽  
Vol 6 (444) ◽  
pp. 111-118
Author(s):  
Т.S. Bazhirov ◽  
◽  
V.S. Protsenko ◽  
N.S. Bazhirov ◽  
M.S. Dauletiyarov ◽  
...  
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Mineralogical Composition ◽  
Average Particle ◽  
Low Carbon ◽  
High Carbon ◽  
Heat Resistant ◽  
Carbon Ferrochrome ◽  
Ferrochrome Production

The research results of physicochemical and physicotechnical properties of slag wastes from ferrochrome production as raw materials for heat-resistant materials are presented. Chemical and mineralogical composition of slag from high-carbon ferrochrome production and slag from low-carbon ferrochrome production, as well as their constituent main crystalline phases, represented by magnesium and calcium aluminosilicates of complex composition, have been determined by physicochemical research methods. According to X-ray phase analysis, the slag from the high-carbon ferrochrome production is represented mainly by forsterite Mg2SiO4, spinel MgAl2O4, partially amorphous glass phase and admixture of calcium orthosilicate Ca2SiO4. In the slag from the low-carbon ferrochrome production, the main crystalline phase is calcium orthosilicate γ-Ca2SiO4, as well as magnesium orthosilicate forsterite Mg2SiО4. The research results of specific surface area, average particle size determination and sieve analysis have shown that the slag from the low-carbon ferrochrome production is a finely dispersed gray powder with the following characteristics: the specific surface area – 295 m2 /kg, the average particle size – 6.8 μm, the true density – 3.01 g/cm3 , the bulk density – 739 kg/m3 . The research of the physicochemical and physicotechnical properties has established that in terms of chemical, mineralogical composition and refractoriness indices, the slags from the high-carbon ferrochrome and low-carbon ferrochrome productions can be valuable raw materials for heat-resistant materials.

scholarly journals PHYSICAL AND CHEMICAL STUDIES OF SLAG OF PRODUCTION OF LOW-CARBON FERROCHROME - COMPONENT OF HEAT-RESISTANT BINDER MATERIAL

2020 ◽  
Vol 63 (6) ◽  
pp. 58-64
Author(s):  
Tynlybek S. Bazhirov ◽  
Muhtar S. Dauletiyarov ◽  
Nurlybek S. Bazhirov ◽  
Bolatzhan E. Serikbayev ◽  
Kamshat N. Bazhirova
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Average Particle Size ◽  
Average Particle ◽  
Sieve Analysis ◽  
Low Carbon ◽  
Heat Resistant ◽  
Carbon Ferrochrome ◽  
Chemical Studies ◽  
Physical And Chemical

The aim of the work is physicochemical studies of chemical and mineralogical composition of the slag from the production of low-carbon ferrochrome proposed to use as a component of heat-resistant binder. As a result of studies, it was found that the main crystal phase in the slag is calcium orthosilicate in the form of γ-Ca2SiO4 modification, which is also partially in the form of α-Ca2SiO4, and magnesian silicates in the form of forsterite Mg2SiО4. The main properties of the slag such as density, specific surface, dispersiveness, refractoriness are determined by the properties of the dominant mineral- calcium orthosilicate. Under conditions of slow cooling of the slag melt, the main mineral in the slag composition, i.e. calcium orthosilicate β-Ca2SiO4 passes into γ-Ca2SiO4 modification with increase in the volume of crystal lattice by ~ 12%, which leads to self-destruction and transition of the slag to a dust state. The results of studies of the specific surface, determination of the average particle size, the results of sieve analysis showed that the slag from the production of low-carbon ferrochrome is a finely dispersed gray powder with the following characteristics: the specific surface is 2955 cm2/g, the average particle size is 6.8 μm, the true density is 3.01 g/cm3, the bulk density is 739 kg/m3. When using the finely dispersed slag from the production of low-carbon ferrochrome as a component of composite binders, the energy-consuming process of its fine grinding can be eliminated. Currently, the slag from the production of low-carbon ferrochrome is practically not used as a secondary mineral raw material. However, the physicochemical properties of the minerals making up the slag allow to recommend it as a component for the manufacture of heat-resistant materials. The results of physical and chemical studies can be used to develop effective technologies for integrated processing of low-carbon ferrochrome slags.

Minimum Particle Diameter of the Vanadium/Iron Co-Doped Nano TiO2 Transparent Hydrosol at Room Temperature

2014 ◽  
Vol 989-994 ◽  
pp. 611-614
Author(s):  
Ling Li ◽  
Wen Ming Zhang ◽  
Hua Yan Zhang ◽  
Zi Hao Xu ◽  
Sen Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Ferric Nitrate ◽  
Average Particle ◽  
Hydrolysis Method ◽  
Vanadium Iron ◽  
Co Doped

Vanadium/iron co-doped nanoTiO2 transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, ferric nitrate, ammonium metavanadate, etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, EDS, nanolaser particle size analyzer, and UV-Vis spectrophotometer. The photocatalytic properties of V/Fe doped TiO2 were studied through degrading acid 3R dye, and the results show that when the content of V/Fe was 0.5%, the degradation rate reached more than 96% under irridation for 60 min.

Rheological, Structural and Mechanical Characterization of Monolithic Zircon-Alumina Bodies

2014 ◽  
Vol 793 ◽  
pp. 151-158 ◽  
Author(s):  
M. León-Carriedo ◽  
C.A. Gutiérrez Chavarría ◽  
J.L. Rodríguez Galicia ◽  
Jorge López-Cuevas ◽  
M.I. Pech Canul
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Mechanical Test ◽  
Average Particle Size ◽  
Young Modulus ◽  
Particle Morphology ◽  
Ceramic Materials ◽  
Transgranular Fracture ◽  
Average Particle

In the present work, the characterization of monolithic materials formulated at different weight concentrations was conducted; employing two of the ceramic materials most used in the refractory industry, zircon and alumina. These monolithic materials were fabricated using colloidal techniques, specifically plaster casting mold, in order to obtain pieces with a higher particle consolidation and density, reducing porosity to lower values than the obtained using traditional shaping process of these materials. The monoliths were obtained employing two ceramic powders with different average particle size and morphology to achieve better packing in the green body. This characterization was carried out, firstly, determining the particle size of the raw materials by laser diffraction and the evaluation of particle morphology by scanning electron microscopy. Aqueous suspensions were formulated by containing both ceramic materials, which were dispersed with Tamol 963, and analyzed by rheometric techniques. Subsequently, bars were manufactured having the following dimensions; 4 mm wide, 3 mm thick and 45 mm in length, according to ASTM C1161-02cc, to be characterized microstructural and mechanically, also was observed the fracture habit after the mechanical test. As a final result, the materials formulated at higher alumina content showed higher density values, reaching 94.95% of the theoretical density, also showed a higher thermal expansion coefficient and high rupture modulus, reaching up to 600 MPa and Young modulus of 230 GPa. From the microstructure characterization it was observed that alumina matrix shows a transgranular fracture across the grains and zircon particles exhibited intergranular fracture among the grain boundaries.

Synthesis of Dispersed Y2O3 Nanopowder from Yttrium Stearate

2013 ◽  
Vol 544 ◽  
pp. 3-7 ◽  
Author(s):  
Jin Sheng Li ◽  
Xu Dong Sun ◽  
Shao Hong Liu ◽  
Di Huo ◽  
Xiao Dong Li ◽  
...  
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Ceramic Materials ◽  
Average Particle ◽  
Water Medium ◽  
Nitrate Hexahydrate ◽  
Yttrium Nitrate ◽  
Ft Ir ◽  
Yttrium Nitrate Hexahydrate

Fine yttrium stearate powder was produced at a relatively low temperature using yttrium nitrate hexahydrate, ammonia and stearic acid as the raw materials. Dispersed Y2O3 nanopowder was synthesized by calcining the yttrium stearate. The formation mechanism of the precursor and the Y2O3 nanopowder was studied by means of XRD, TG-DTA, FT-IR, BET, FE-SEM and HR-TEM. Pure and dispersed Y2O3 nanopowder with an average particle size of 30 nm was produced by calcining the precursor at 600 °C. The particle size increases to about 60 nm with the increase of the calcination temperature to 1000 °C. In the preparation of Y2O3 from yttrium stearate, no water medium is involved, thus capillarity force and bridging of adjacent particles by hydrogen bonds can be avoided, resulting in good dispersion of the particles. The dispersed Y2O3 nanopowder prepared in this work has potential application in phosphors and transparent ceramic materials.

scholarly journals Preparation of the monodispersed carboxyl-functionalized polymer microspheres with disproportionated rosin moiety and adsorption of methylene blue

2018 ◽  
Vol 36 (5-6) ◽  
pp. 1260-1273 ◽  
Author(s):  
Cai-Li Yu ◽  
Feng Bian ◽  
Shu-Fen Zhang ◽  
Xu Xu ◽  
Peng Ren ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Average Particle ◽  
Polymer Microspheres ◽  
Carboxyl Content ◽  
Methylene Blue Adsorption

Carboxyl-functionalized polymer microspheres with a rosin moiety were prepared through dispersion polymerization using styrene, disproportionated rosin ester, and methylacrylic acid as raw materials. The effects of dispersion medium (ethanol/water) ratio, monomer mass proportion and initiator concentration on the polymer microspheres were studied. Scanning electron microscopy, laser particle size analysis, thermogravimetric analysis and Fourier transform infrared spectroscopy were used to characterize the microspheres, and their carboxyl contents were determined by the conductance titration method. The adsorption of methylene blue of the microspheres was also investigated. The results showed that rosin-based carboxyl-functionalized polymer microspheres were successfully synthesized. The microspheres exhibited smooth, spherical shapes with good monodispersity and high thermal stability. The carboxyl content of the microspheres prepared under optimum conditions was 0.089 mmol·g−1, with the average particle size approximately 950 nm. With increasing carboxyl contents of the polymer microspheres, their methylene blue adsorption capacities increased. The maximum methylene blue adsorption capacity of the microspheres was 59.55 mg·g−1 in the highest carboxyl content.

Encapsulation of Pigment Using Natural Polysaccharides

2012 ◽  
Vol 441 ◽  
pp. 494-502
Author(s):  
Manal Moustafa Rekaby ◽  
Qin Guo Fan
Keyword(s):  
Particle Size ◽  
Maleic Anhydride ◽  
Raw Materials ◽  
Average Particle Size ◽  
Miniemulsion Polymerization ◽  
Average Particle ◽  
Chemical Crosslinking ◽  
Shell Material ◽  
Uv Curable ◽  
Polysaccharide Derivatives

With a view to developing UV curable systems from renewable biocompatible raw materials, the present work deals with the encapsulation of pigments with polysaccharide derivatives that can undergo crosslinking upon exposure to UV radiation. Maleate ester derivatives were prepared in anhydrous conditions using maleic anhydride in the presence of pyridine. Encapsulation of the pigment core in the prepared UV curable systems occurred by applying the prepared guar derivative as a shell material in a UV curable formulation that can be induced by a photoinitiator. Encapsulation is done by the o/w/o miniemulsion polymerization technique. In another approach, and for the sake of comparison, microencapsulation was performed via chemical crosslinking of the prepared guar maleate derivative in a W/O emulsion .The resultant nanocapsules were characterized using FTIR, DSC, and SEM. The nanocapsules were spherical with average particle size of 100 nm.

Minimum Particle Diameter of the Sulfur-Doped Nano-TiO2 Transparent Hydrosol at Room Temperature

2014 ◽  
Vol 587-589 ◽  
pp. 788-791
Author(s):  
Ling Li ◽  
Hua Yan Zhang ◽  
Xiao Wei Li ◽  
Zi Hao Xu ◽  
Sen Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Photocatalytic Performance ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Synthesis Process ◽  
Average Particle ◽  
Hydrolysis Method ◽  
Particle Size Analyzer

Sulfur-doped nanoTiO2transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, thiourea, organic carboxylic acid, NH3H2O, D-sorbitol etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, nanolaser particle size analyzer, ultraviolet-visible spectrophotometer. In addition, the influence of reaction conditions in the synthesis process was also studied. The results indicate that when nanoparticle doped with 0.5% S, and the reflux time was 15 min, the photocatalytic performance of sulfur-doped TiO2hydrosol was best.

Synthesis and Characterization of Monodisperse Nanocrystalline HZSM-5 Zeolite

2013 ◽  
Vol 423-426 ◽  
pp. 135-138
Author(s):  
Jun Fang Wei ◽  
Fang Zhu ◽  
Xiao Yan Zhang
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Ammonium Hydroxide ◽  
Crystallization Time ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Influence Of Crystallization

A monodisperse nanocrystalline HZSM-5 zeolite was prepared by varying-temperature synthesis method with aluminum nitrate (Al (NO3)3), tetraethyl orthosilicate (TEOS), and tetrapropyl ammonium hydroxide (TPAOH) as raw materials. X-ray diffraction (XRD) characterization results showed that the crystallinity of HZSM-5 prepared by varying-temperature synthesis method was higher than constant-temperature synthesis . The influence of crystallization temperature and time on morphology and particle size of HZSM-5 is represented by scanning electronic microscopy (SEM) characterization: nanocrystalline HZSM-5 with more regular morphology and smaller particle size can be prepared by varying-temperature synthesis method. The minimum average particle size is 0.3μm. The particle size will grow up to 3.0μm with the crystallization time prolonged.

The Preparation and Characteristics of Chitosan-Acetaminophen Drug-Loading Micropheres

2012 ◽  
Vol 586 ◽  
pp. 161-165 ◽  
Author(s):  
Hao Ran Zhou ◽  
Jing Yu Zhang ◽  
Hao Jiang
Keyword(s):  
Particle Size ◽  
Sustained Release ◽  
Raw Materials ◽  
Orthogonal Experiment ◽  
Drug Loading ◽  
Average Particle Size ◽  
Average Particle ◽  
Preparation Process ◽  
Structure And Morphology ◽  
Ft Ir

CS-ACAP drug-loading microsperes are prepared with using CS and ACAP as the main raw materials by emulsification-crosslinking method. Orthogonal experiment was designed to optimize the preparation process of the CS-ACAP drug-loading microspheres. FT-IR and SEM were applied to characterize the structure and morphology of microspheres. The sustained release effect of CS-ACAP microsphere was measured by sustained release measurement. The results showed that the CS-ACAP drug-loading micropheres were successfully prepared by emulsification-crosslinking method. Obtained microspheres as a perforated sphere, the average particle size of the microspheres was 30μm and the microspheres had a uniformly particle size distribution; the drug-loaded microspheres had good sustained release effect.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

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