Effect of mechanically activated raw materials on β-sialon formation by combustion synthesis

The influence of different raw material mixtures on β-sialon (Si6−zAlzOzN8−z, 1 ⩽ z ⩽ 4) formation through mechanical activation coupled combustion synthesis (MA-CS) was investigated in low nitriding atmosphere of 1 MPa without diluent inclusions. The MA-CS performed for the first time on sialon raw materials with milling time of 18 min obtained sialons more than three times as pure as those obtained by CS of mixtures ball milled to 1 h (z = 3). The starting materials containing silicon, aluminum, and alumina (z = 4) after MA-CS had an increment of sialon amounts up to 88 mass%.

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New data on flint processing of East Trypillia tribes of the Bug-Dnieper interfluve

Vita Antiqua ◽

10.37098/va-2021-13-113-128 ◽

2021 ◽

pp. 113-128

Author(s):

Ye.V. Pichkur ◽

Keyword(s):

Raw Materials ◽

Raw Material ◽

Production Waste ◽

The West ◽

Quantitative Ratio ◽

Lithic Industry ◽

Modern Level ◽

First Time ◽

Local Nature

For the first time, materials of such settlements of the East Trypillia culture as Trostyanchyk, Onopriyivka І are published. Despite approximately the same quantitative ratio, even at first glance, the materials of these two leaflets differ significantly from each other. The Trostyanchyk complex is actually blade-type: blades prevail both among production waste and among the tool kit. Flakes and tools on them dominate in Onopriyivka. If the Trostyanchyk complex can be regarded as "classic" in terms of the tool kit: retouched blades, end-scrapers, sickle inserts, perforators on blades, etc., then the Onopriyivka complex looks more primitive: retouched flakes, notched tools and scrapers on flakes, and others. In Onopriyivka, unlike Trostyanchyk, finds of weapons are completely absent. Products from Onopriyivka are made mainly of local raw materials, while in Trostyanchyk there are approximately equal parts of products from local and imported raw materials, and products from local flint are made as carefully as products from Volyn flint. At the same time, in both cases we can confidently speak of the local nature of production. This is evidenced by both the use of local flint raw material and the specific items present in both collections. In Trostyanchyk, as already mentioned, a hammerstone was found, in Onopriyivka — core-like fragments and chips of modify of cores. Such differences can be explained by both territorial and chronological discrepancies. Onopriyivka I is earlier, refers to the end of stage ВІ, Trostyanchyk — to the end of stage ВІІ. Trostyanchyk is located on the Southern Bug, Onopriyivka — in the Bugo-Dnieper interfluve. Although, perhaps, this situation is explained by the unevenness of the study of these sites. In addition, materials from the Vladyslavchyk settlement are published for the first time. Based on their analysis, using analogies from related and synchronous sites, the author tried to identify the features of the East Trypillia lithic industry in the Bug-Dnieper rivers interfluve. As it turned out, at the modern level, the identification of such features is not possible. The materials of the East Trypillia culture of the region are, on the whole, more similar to the materials of the settlements of the West Trypillia culture, than to related sites on the Southern Bug. Keywords: East Trypillia culture, Kukutenʹ-Trypillya, production, flint processing, Bug-Dnieper interfluve

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PYROMILLING SYNTHESIS OF NANOCRYSTALLINE TITANIUM CARBIDE

NANO ◽

10.1142/s1793292013500239 ◽

2013 ◽

Vol 08 (02) ◽

pp. 1350023 ◽

Cited By ~ 3

Author(s):

M. RAZAVI ◽

S. ZAMANI ◽

M. R. RAHIMIPOUR ◽

P. KHATIBZADEH

Keyword(s):

Titanium Carbide ◽

Crystallite Size ◽

Milling Time ◽

Raw Materials ◽

Lattice Parameter ◽

Stoichiometric Ratio ◽

Nanocrystalline Titanium ◽

Standard Value ◽

Increasing Temperature ◽

First Time

For the first time, pyromilling synthesis for production of nanocrystalline titanium carbide was presented in this research. Raw materials containing stoichiometric ratio of titanium and carbon were milled and heated simultaneously. Samplings were done at different times. Then, phase transformation, crystallite size and strain of samples were estimated by XRD technique. Microstructures of milled samples were studied by SEM and TEM. Results showed that by increasing temperature, milling time for synthesizing of titanium carbide was reduced. Crystallite size of milled samples were in nanometer scale which were reduced by increasing of milling time and decreasing of temperature while strain was intensified. Existence of created strain changed lattice parameter of synthesized titanium carbide from standard value.

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Agro-Morphological, Microanatomical and Molecular Cytogenetic Characterization of the Medicinal Plant Chelidonium majus L.

Plants ◽

10.3390/plants9101396 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1396

Author(s):

Tatiana E. Samatadze ◽

Olga Y. Yurkevich ◽

Firdaus M. Hazieva ◽

Elena A. Konyaeva ◽

Alexander I. Morozov ◽

...

Keyword(s):

Medicinal Plant ◽

Raw Materials ◽

Morphological Variability ◽

5S Rdna ◽

Raw Material ◽

Chelidonium Majus ◽

Diagnostic Features ◽

Molecular Cytogenetic ◽

Cytogenetic Characterization ◽

First Time

Chelidonium majus L. is a medicinal plant well-known as a valuable source of isoquinoline alkaloids, which has a variety of pharmacological properties including anti-viral and anti-bacterial effects. However, considerable intraspecific bio-morphological variability in C. majus complicates raw material identification and verification. For the first time, we have brought into cultivation five populations of C. majus subsp. majus originated from different regions, and performed their agro-morphological, microanatomical and molecular cytogenetic characterization. All examined populations produced high seed (18.6–19.9 kg/ha) and raw material (0.84–1.08 t/ha) yields; total alkaloid contents were within 0.30–0.38%. Nevertheless, significant differences in plant morphology and yield-contributing traits were observed. The performed microanatomical analysis of leaves and flowers in double- and normal-flowered plants revealed micro-diagnostic features (including tissue topography, types of stomata, laticifers, structure of leaf mesophyll, hairs, sepals and petals) important for identification of C. majus raw materials. The analysis of chromosome morphology, DAPI-banding patterns, FISH mapping of 45S and 5S rDNA and also chromosome behavior in meiosis allowed us to identify for the first time all chromosomes in karyotypes and confirm relative genotype stability of the studied plants. Our findings indicate that the examined C. majus populations can be used in further breeding programs.

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Ti-Al-Nb Material for High-Temperature Applications: Combustion Synthesis from Oxide Raw Materials

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.746.262 ◽

2017 ◽

Vol 746 ◽

pp. 262-266

Author(s):

D.E. Andreev ◽

V.I. Yukhvid ◽

Denis M. Ikornikov ◽

Vladimir N. Sanin

Keyword(s):

High Temperature ◽

Combustion Synthesis ◽

Raw Materials ◽

High Gravity ◽

Target Product ◽

Oxide Materials ◽

Centrifugal Shs ◽

First Time ◽

Metallic Impurities ◽

Temperature Applications

This work is focused on preparation of Nb-doped Ti–Al material (Ti–29.3Al–17.6Nb wt %) by centrifugal SHS. Results of studying of combustion and synthesis regularities of intermetallic material on γ-TiAl base from oxide materials under high gravity are presented in the article. For the first time is used a reduction mixture on Al/Ca base which markedly increases the yield of Ti–Al–Nb and decreases the amount of non-metallic impurities (oxygen, nitrogen, carbon) in target product.

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The Potential for REE and Associated Critical Metals in Karstic Bauxites and Bauxite Residue of Montenegro

Minerals ◽

10.3390/min11090975 ◽

2021 ◽

Vol 11 (9) ◽

pp. 975

Author(s):

Slobodan Radusinović ◽

Argyrios Papadopoulos

Keyword(s):

Raw Materials ◽

Bauxite Residue ◽

Raw Material ◽

Late Triassic ◽

Critical Metals ◽

Critical Elements ◽

Secondary Raw Material ◽

Increasing Demand ◽

First Time ◽

Critical Raw Materials

Research for critical raw materials is of special interest, due to their increasing demand, opulence of applications and shortage of supply. Bauxites, or bauxite residue after alumina extraction can be sources of critical raw materials (CRMs) due to their content of rare earth elements and other critical elements. Montenegrin bauxites and bauxite residue (red mud) are investigated for their mineralogy and geochemistry. The study of the CRM’s potential of the Montenegrin bauxite residue after the application of Bayer process, is performed for the first time. Montenegrin bauxites, (Jurassic bauxites from the Vojnik-Maganik and Prekornica ore regions from the Early Jurassic, Middle Jurassic-Oxfordian and Late Triassic paleorelief) are promising for their REE’s content (around 1000 ppm of ΣREE’s). More specifically, they are especially enriched in LREEs compared to HREEs. Regarding other CRMs and other elements, Ti, V, Zr, Nb, Sr and Ga could also be promising. In bauxite residue, the contents of Zr, Sr, V, Sc, La, Ce, Y, Ti and Nb are higher than those in bauxites. However, raw bauxites and bauxite residue as a secondary raw material can be considered as possible sources of CRMs.

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Effect of Mechanical Activation on the Synthesis of Ba-Celsian and Sr-Celsian using Precursor Mixtures Containing Coal Fly Ash

MRS Proceedings ◽

10.1557/opl.2016.23 ◽

2016 ◽

Vol 1812 ◽

pp. 89-94

Author(s):

Claudia M. Lopez-Badillo ◽

Jorge López-Cuevas ◽

Carlos A. Gutiérrez-Chavarría ◽

José L. Rodríguez-Galicia ◽

Elia M. Múzquiz-Ramos

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Solid State ◽

Mechanical Activation ◽

Solid State Reaction ◽

Milling Time ◽

Coal Fly Ash ◽

Raw Material ◽

Attrition Mill ◽

Sintered Materials

ABSTRACTBaAl2Si2O8 and SrAl2Si2O8 were synthesized by solid-state reaction of stoichiometric mixtures of either BaCO3 or SrCO3 with coal fly ash and Al2O3. The mixtures were mechanically activated in an attrition mill for up to 12 h and then reaction-sintered at 900-1300 °C, aiming to promote the formation of BaAl2Si2O8 and SrAl2Si2O8 as well as the conversion from their hexagonal (Hexacelsian) into their monoclinic (Celsian) forms, which is associated with improved mechanical properties in the sintered materials. Especially in the case of SrAl2Si2O8, the formation of Celsian was favored at relatively low sintering temperatures by increasing milling time. Although only the SrAl2Si2O8 composition was fully converted into Celsian, the Hexacelsian to Celsian conversions obtained for the mechanically-activated BaAl2Si2O8 composition were significantly higher than those previously reported in the literature for this compound. This could be attributed to the use of coal fly ash as raw material, which contains mineralizers that promote the mentioned conversion.

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Combustion Synthesis of β-SiAlON Using 3D Ball Milling

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1717 ◽

2017 ◽

Vol 898 ◽

pp. 1717-1723 ◽

Cited By ~ 1

Author(s):

Xue Mei Yi ◽

Shota Suzuki ◽

Xiong Zhang Liu ◽

Ran Guo ◽

Tomohiro Akiyama

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Combustion Synthesis ◽

Ball Mill ◽

Raw Materials ◽

Raw Material ◽

Size Distributions ◽

Particle Size Distributions ◽

Material Particle

Combustion synthesis (CS) of β-SiAlON was conducted using a 3D ball mill, with a focus on the effect of the 2D/3D ball mill premixing conditions on the CS raw material particle size as well as on the yield and grain shape of the final products. The results showed that the particle size distribution of the raw materials was significantly affected by the premixing conditions. Various particle sizes and particle size distributions could easily be obtained by using a 3D mill instead of a 2D mill due to the complex biaxial rotation movement of 3D milling. The particle size was more sensitive to the rotation ratio (vertical spin/horizontal spin, Vv/Vh) than the rotation rate when using 3D milling. Finally, β-SiAlON with less than 5 mass% unreacted Si was obtained using premix milling conditions of 135×200 [vertical spin (rpm) × horizontal spin (rpm)]. The grain shapes of the final products were clearly influenced by the particle size distribution of the raw mixtures.

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New challenges in the study of lithic raw materials in central Italy at the dawn of metal working societies: La Pietra and other radiolarite quarry-workshops in Tuscany

Journal of Lithic Studies ◽

10.2218/jls.v3i2.1466 ◽

2016 ◽

Vol 3 (2) ◽

Cited By ~ 1

Author(s):

Sem Scaramucci ◽

Vanessa Volpi ◽

Armando Costantini ◽

Marco Giamello ◽

Alessandro Donati ◽

...

Keyword(s):

Raw Materials ◽

Methodological Approach ◽

Central Italy ◽

Raw Material ◽

Copper Age ◽

Field Surveys ◽

Archaeological Data ◽

Geochemical Analyses ◽

First Time ◽

Non Destructive

In central-southern Tuscany radiolarite has been used as a lithic raw material throughout prehistory. During the Copper Age it was selected for the local production of leaf-shaped artefacts. In the area considered, the Copper Age record is almost totally restricted to burials and virtually no settlements have been investigated so far. Radiolarite artefacts are found mostly as refined arrow and, possibly javelin, heads used as grave goods.Within this context, the discovery and recent investigation of the large radiolarite quarry of La Pietra (Roccastrada, Grosseto) and of the related workshops is of great interest. Our aim here is to integrate the record from this site with other contemporary evidence of radiolarite exploitation. A programme of surveys has thus begun on the other radiolarite outcrops of the area in order to verify the existence of further rock quarrying or working. The discovery of a previously unknown quarry-workshop and two previously unknown workshops on radiolarite outcrops is presented here for the first time. The geological and archaeological data coming from the quarry-workshops will be used, in a future stage of research, to source the radiolarite artefacts found in Copper Age graves of Central Italy. The Copper age armatures are valuable artefacts mostly kept in museums and fully non-destructive analyses must be applied to them. To tackle these challenges, we followed a methodological approach which integrates field surveys, the individuation of petrographic markers of the most exploited radiolarite horizons and geochemical analyses. For geochemical characterization, we made use of pXRF portable spectrometer and here we present some preliminary results in the light of current methodological debate.In conclusion, even if some methodological questions remain open, we verified the feasibility of this programme of geographical, geological and geochemical characterizations and need now to increase our dataset in order to reconstruct a viable picture of Copper age lithic economy in central-southern Tuscany.

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THERMAL DECOMPOSITION OF GRANULAR BIOFUEL OBTAINED BY DIFFERENT METHODS OF ACTIVATION

Thermophysics and Thermal Power Engineering ◽

10.31472/ttpe.4.2020.6 ◽

2020 ◽

Vol 42 (4) ◽

pp. 50-58

Author(s):

T.V. Korinchevska ◽

V.A. Mykhailyk

Keyword(s):

Thermal Decomposition ◽

Mechanical Activation ◽

Thermal Activation ◽

Raw Materials ◽

Average Rate ◽

Indirect Evidence ◽

Decomposition Process ◽

Raw Material ◽

Organic Substances ◽

Wood Sawdust

The article considers the effect of the granulometric composition of pine wood sawdust and granulation modes on the thermal decomposition of biofuel. Mechanical activation and thermal activation of raw materials before pressing were used in the study. Thermal decomposition of granular fuel was carried out by the methods of thermogravimetry and differential thermal analysis. The temperature ranges of dehydration, thermal decomposition of organic and mineral substances, moisture and ash content of the fuel have been determined. The rates of thermal decomposition of organic substances in granular fuel were also determined. The thermal effects of thermal decomposition of the granule samples were compared. It is registered that the equilibrium moisture content of granules obtained after thermal activation of the raw material is lower than that for granules made by cold pressing. This is indirect evidence of their increased density. It has been determined that most of the heat of thermal decomposition of organic substances in granular fuels is released in the high-temperature period at a decomposition rate of 1,12 to 1,37 % dry matter per minute. It was revealed that the thermal effect of thermal decomposition of granules depends on the fractional composition of the ground raw materials. This may be due to the difference in the chemical composition of the fractions. The analysis of obtained results made it possible to determine that the mechanical activation of raw materials increases the average rate of granule decomposition, and thermal activation reduces it. That is, the mechanical activation of raw materials has a positive effect on the thermal decomposition process. Grinding wood sawdust to particles smaller than 0,2 mm can lead to partial destruction of complex macromolecular compounds (hemicellulose, cellulose and lignin). Thus, this leads to a decrease in the degree of intermolecular interaction and intensification of the decomposition process.

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Synthesis, Characterization and Properties of Forsterite Refractory Produced from Thai Talc and Magnesite

Materials Science Forum ◽

10.4028/www.scientific.net/msf.940.46 ◽

2018 ◽

Vol 940 ◽

pp. 46-50

Author(s):

Surapattanapong Kullatham ◽

Sakdiphon Thiansem

Keyword(s):

Physical Properties ◽

Mechanical Activation ◽

Ball Mill ◽

Milling Time ◽

Raw Materials ◽

True Density ◽

X Ray Diffraction ◽

X Ray ◽

Xrf Scanning ◽

Subsequent Calcination

This paper reports the synthesis, characterizations, microstructure and properties of forsterite powder produced in Thailand from talc and magnesite as raw materials by using mechanical activation with subsequent calcination. The synthesis forsterite powder were mixed by using talc and magnesite at 1:5 mole ratio. The maximum milling time was 24 h in a planetary zirconia ball mill. Afterward, the mixtures were calcined in an electric furnace for 1 h at 900, 1000, 1100, 1200 and 1300°C respectively. The synthesized powder was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and physical properties. Results of the physical properties of synthesized forsterite showed an increased in density as the calcining temperature increased. In contrast, porosity was decreased with an increase of the calcining temperature. Therefore, forsterite that was calcined at 1300°C provided the best results which were 2.96 g/cm3 of true density and 15.41% of true porosity. Results of XRD of synthesized powder indicated that the forsterite crystallization was constant for which sharpen appeared after 5 h of mechanical activation. Fraction of forsterite was appeared after being calcined at 1000°C for 1 h with an increasing of calcination temperature, the fraction of forsterite phase increased. Based on the mentioned characteristics, the forsterite produced from Thai talc and magnesite exhibited properties of an insulator and can potentially be used as refractory devices.

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