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

Author(s):  
Tynlybek S. Bazhirov ◽  
Muhtar S. Dauletiyarov ◽  
Nurlybek S. Bazhirov ◽  
Bolatzhan E. Serikbayev ◽  
Kamshat N. Bazhirova

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.

2020 ◽  
Vol 6 (444) ◽  
pp. 111-118
Author(s):  
Т.S. Bazhirov ◽  
◽  
V.S. Protsenko ◽  
N.S. Bazhirov ◽  
M.S. Dauletiyarov ◽  
...  

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.


2019 ◽  
Vol 19 (02) ◽  
pp. 1950014
Author(s):  
Sabereh Nazari ◽  
Sadegh Nazari ◽  
Fariba Mansourizadeh ◽  
Gholamreza Karimi

In this study, high purity gamma-alumina nanopowders with crystalline structures have been prepared via a sol–gel process by waste metal aluminum, HCl, NaOH, Polyethylene glycol (PEG) and polyvinyl alcohol (PVA). Polyethylene glycol and polyvinyl alcohol have been used as stabilizing agents. The characterization of the samples has been performed utilizing XRD, FTIR, SEM, N2 adsorption/desorption techniques. Prepared samples of gamma-alumina at 800∘C with PEG has an average crystallite size of 2.58[Formula: see text]nm, average particle size of 21[Formula: see text]nm, specific surface area (SSA) of 65.55[Formula: see text]m2/g, and pore volume of [Formula: see text]0.06[Formula: see text]cm3/g. The average crystallite size of 3.07[Formula: see text]nm, average particle size of 31[Formula: see text]nm, specific surface area of 131.25[Formula: see text]m2/g, and pore volume of [Formula: see text]0.14[Formula: see text]cm3/g, were obtained using PVA surfactant.


2016 ◽  
Vol 7 ◽  
pp. 721-732 ◽  
Author(s):  
Jacek Wojnarowicz ◽  
Roman Mukhovskyi ◽  
Elzbieta Pietrzykowska ◽  
Sylwia Kusnieruk ◽  
Jan Mizeracki ◽  
...  

Mn-doped zinc oxide nanoparticles were prepared by using the microwave solvothermal synthesis (MSS) technique. The nanoparticles were produced from a solution of zinc acetate dihydrate and manganese(II) acetate tetrahydrate using ethylene glycol as solvent. The content of Mn2+ in Zn1− x Mn x O ranged from 1 to 25 mol %. The following properties of the nanostructures were investigated: skeleton density, specific surface area (SSA), phase purity (XRD), lattice parameters, dopant content, average particle size, crystallite size distribution, morphology. The average particle size of Zn1− x Mn x O was determined using Scherrer’s formula, the Nanopowder XRD Processor Demo web application and by converting the specific surface area results. X-ray diffraction of synthesized samples shows a single-phase wurtzite crystal structure of ZnO without any indication of additional phases. Spherical Zn1− x Mn x O particles were obtained with monocrystalline structure and average particle sizes from 17 to 30 nm depending on the content of dopant. SEM images showed an impact of the dopant concentration on the morphology of the nanoparticles.


2010 ◽  
Vol 92 ◽  
pp. 163-169
Author(s):  
Hong Xia Qiao ◽  
Zhi Qiang Wei ◽  
Ming Ru Zhou ◽  
Zhong Mao He

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Hongxia Qiao ◽  
Zhiqiang Wei ◽  
Hua Yang ◽  
Lin Zhu ◽  
Xiaoyan Yan

NiO nanoparticles with average particle size of 25 nm were successfully prepared by anodic arc plasma method. The composition, morphology, crystal microstructure, specific surface area, infrared spectra, and particle size distribution of product were analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED), Fourier transform infrared (FTIR) spectrum, and Brunauer-Emmett-Teller (BET)N2adsorption. The experiment results show that the NiO nanoparticles are bcc structure with spherical shape and well dispersed, the particle size distribution ranging from 15 to 45 nm with the average particle size is about 25 nm, and the specific surface area is 33 m2/g. The infrared absorption band of NiO nanoparticles shows blue shifts compared with that of bulk NiO.


2014 ◽  
Vol 698 ◽  
pp. 452-456 ◽  
Author(s):  
Ekaterina A. Nosova ◽  
Antonina A. Kuzina ◽  
Anna V. Kuts

Compacting after pressing and sintering of briquettes made from an aluminum powder with an average particle size from 50 to 150 microns, the specific surface area Ssp=0.26 m2/g and a nickel powder with an average particle size from 25 to 100 microns, the specific surface area Ssp= 0.03 m2/g has been investigated. Pressing load varied from 15 to 25 MPa for the aluminum powder and from 20 to 45 MPa for the nickel powder. Sintering of aluminum powder briquettes was carried out at temperatures (0.5-0.83) of melting temperature, (0.3-0.46) of melting temperature from the nickel powder. It is shown that the application of high pressure, low temperatures and short time makes it possible to receive pseudo-ligatures from an aluminum powder with porosity about 32% and a nickel powder with porosity about 30%.


2018 ◽  
Vol 22 (4) ◽  
pp. 43-49
Author(s):  
Marcin Natoniewski ◽  
Leszek Rydzak ◽  
Agata Wyciszkiewicz ◽  
Tomasz Guz

AbstractIn recent years, a dynamic development of brewing has been observed. Increasingly, production of malt and beer takes place even in smaller industrial factories, breweries restaurants or at home. Extraction is a process applied in a variety of industries, including food production, as a way of extracting specific ingredients from their mixtures. As a result of this process, not only sugars, proteins, fats, enzymes, vitamins, colorants, fragrances and flavors, but also malt and hop extracts are being isolated. In the process of mashing, in which the malt ingredients are being extracted, many biochemical, physical and chemical changes take place. The aim of the study was to analyze the effect of the degree of fragmentation of pilsner type malt on the amount of extract obtained and the pH of the mash. It has been observed that the degree of malt fragmentation has a significant effect on the content of the extract in the mash: the more fragmented malt, the more malt extract in mash produced using the malt. It has also been found that the pH of the mash increases with the average particle size of malt.


2007 ◽  
Vol 119 ◽  
pp. 43-46
Author(s):  
Sang Jin Lee ◽  
Choong Hwan Jung

Nano scaled mullite (3Al2O3·2SiO2) powders had been fabricated by an organic-inorganic solution technique using a polyvinyl alcohol (PVA) as an organic carrier. PVA polymer contributed to a soft and porous powder microstructure, and ball milling with the porous powder was effective in making nano-sized mullite powders. In addition, the degree of polymerization of PVA affected the crystallization behavior. The fully crystallized and ball-milled mullite powders had an average particle size of 120 nm with a specific surface area of 67.0 m2/g. In this paper, the simple solution technique and milling process for the fabrication of nano scaled mullite powders are introduced. And the effects of PVA on the crystallization behavior and powder specific surface area are also studied. The characteristics of the synthesized powders are examined by using XRD, TEM, particle size analyzer and nitrogen gas adsorption.


2011 ◽  
Vol 415-417 ◽  
pp. 751-755
Author(s):  
Zhi Qiang Wei ◽  
Xiao Juan Wu ◽  
Li Gang Liu ◽  
Ge Zhang

In the protecting inert gas, Aluminum nanoparticles were successfully prepared by anodic arc discharge plasma method. The morphology, particle size, crystal microstructure and specific surface area of the particles by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller(BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experimental results indicate that the crystal structure of the samples is face centered cubic (fcc) structure as same as the bulk materials, the particle size distribution ranging from 20 to 70 nm, with an average particle size about 44 nm obtained by TEM and confirmed by XRD and BET results. The specific surface area is 41 m2/g, the nanopowders distributed uniformly in spherical chain shapes with uniform size and monodisperse particles.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5486
Author(s):  
Shuangping Yang ◽  
Tiantian Zhang ◽  
Shouman Liu ◽  
Haixing Sun

The effect of microwave activation on the properties of oxidation roasting for molybdenite was investigated under the protection of inert gas, and the specific surface area, the oxidation properties, lattice constant, microstructure, and shape of molybdenite were analyzed and characterized by a laser particle size analyzer, thermogravimetry (TG), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that microwave activation could effectively reduce the residual amount of sulfur in the molybdenum calcine and decrease the average particle size of molybdenite while increasing the specific surface area of molybdenite. On increasing the microwave activation power, the crystal cell volume and grain size of MoS2 reduced, and the microstrain increased slightly. At the same time, the surface shape of molybdenite became looser, but the layered structure is not changed. In addition, the oxidation property changed significantly; microwave activation promoted the oxidation reaction of molybdenite above 538 °C, and the rate of weight loss increased from 6.177% to 7.718% at 620 °C.


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