scholarly journals Transformation of grains of technological raw materials in the process of obtaining fine powders

2021 ◽  
Vol 249 ◽  
pp. 401-407
Author(s):  
Irina Gembitskaya ◽  
Maria Gvozdetskaya
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sample Preparation ◽  
Raw Materials ◽  
Morphological Changes ◽  
X Ray ◽  
Technological Processes ◽  
Fine Powders ◽  
Ultrafine Grinding ◽  
Scanning Electron

Crushing and grinding of materials are the most common processes of sample preparation for subsequent analysis and industrial application. Recently, grinding has become one of the most popular methods for producing nano-sized powders. This study investigates certain features of grain transformation in the process of grinding ores with finely dispersed valuable components in order to liberate them, as well as specifics of grinding metallurgical raw materials, metals and their mixtures for using them as initial components in metallurgical and other technological processes. We identified and examined structural and morphological changes of various powders after ultrafine grinding using the methods of scanning electron microscopy and X-ray microanalysis. It was proved that in order to take into account sample preparation artifacts during analytic studies of solid samples and development of technological processes, fine grinding of heterogeneous materials, especially if they contain metals, requires monitoring of the ground product by methods of scanning electron microscopy and X-ray microanalysis.

Controlled Synthesis LaPO4 Nanorods via a Hydrothermal Route

2013 ◽  
Vol 873 ◽  
pp. 195-199
Author(s):  
Jie Dai ◽  
Kai Li Liu ◽  
Xia Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Morphological Changes ◽  
Photo Luminescence ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
X Ray ◽  
Scanning Electron

LaPO4nanorods have been selectively synthesized via a hydrothermal route, using La (NO3)3·6H2O and NaH2PO4as raw materials, without using any catalyst or template. X-ray diffraction (XRD), scanning electron microscopy (SEM), IR spectra (IR) and photo-luminescence (PL) spectra were used to characterize the as-prepared samples. The morphological changes of the products due to the different mole ratios of La (NO3)3·6H2O and NaH2PO4were studied. The effect of the thermal treatment on the structure of the LaPO4nanorods was also investigated. In addition, the emission intensity of LaPO4nanorods with different Eu doped concentration was compared and discussed.

scholarly journals Sintering of anorthite based ceramics prepared from kaolin DD2 and calcite

Cerâmica ◽  
2016 ◽  
Vol 62 (364) ◽  
pp. 317-322 ◽  
Author(s):  
S. Zaiou ◽  
A. Harabi ◽  
E. Harabi ◽  
A. Guechi ◽  
N. Karboua ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Raw Materials ◽  
Bimodal Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fine Powders ◽  
Different Temperatures ◽  
Scanning Electron

Abstract In this work, the preparation of anorthite based ceramics using a modified milling system and 80 wt% kaolin (DD2 type) and 20 wt% calcium oxide extracted from CaCO3 is shown. The choice of these raw materials was dictated by their natural abundance. Previous studies have shown that a simple and vibratory multidirectional milling system using a bimodal distribution of highly resistant ceramics can be successfully used for obtaining fine powders. The prepared samples were sintered at different temperatures ranging between 800 and 1100 °C. It has been found that the relative density of samples sintered at 900 °C for 1 h with a heating rate of 5 °C/min was about 96% of the theoretical density of anorthite (2.75 g/cm3). Finally, the prepared samples were also characterized by scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

Influence of Fly Ash on Corrosion Resistance of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Zones ◽  
Refractory Ceramics ◽  
Scanning Electron

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

Preparation and Properties of CaF2 Nano-Powder

2016 ◽  
Vol 680 ◽  
pp. 257-260
Author(s):  
Meng Yun Dong ◽  
Cheng Zhang ◽  
Jin Feng Xia ◽  
Hong Qiang Nian ◽  
Dan Yu Jiang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Sintering Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Direct Precipitation ◽  
Scanning Electron

CaF2 nano-power was prepared by direct precipitation methods with Ca(NO3)2 and KF as raw materials. The influences of presintering temperature and sintering temperature on the particle size and distribution of CaF2 nano-power were studied by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). This study provided an experimental method for preparation of CaF2 nano-power. The results show that the best presintering temperature of CaF2 nano-power is 500°C and the best sintering temperature of CaF2 ceramic is 900°C.

Preparation and Properties of Sintering Brick from Iron Tailings

2012 ◽  
Vol 512-515 ◽  
pp. 1023-1027
Author(s):  
Ran Fang Zuo ◽  
Gao Xiang Du ◽  
Le Fu Mei ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Raw Materials ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw ◽  
Scanning Electron

The main objective of this paper was to investigate the addition of iron tailing sintering brick production, in the presence of clay, coal refuses and bentonite. Mixtures containing raw materials of sintering brick and iron tailings were prepared at different proportions (up to 55 wt %), fired at 980°C. Freeze/thaw durability, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density and compressive strength of the fired samples. Their mechanical and microstructure properties were also investigated by differential thermal analysis (DTA/TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the brick samples are higher than that required by the standards MU15 of GB5101-2003, up to 21.79Mpa with 40% iron tailings corresponding to its higher bulk density completely. Moreover, the results showed that it has such advantages as no lime blowing, uniform color, good freeze/thaw resistance and slight universal frost.

Sign in / Sign up

Export Citation Format

Share Document