scholarly journals FEATURES OF THE FORMATION OF THE STRUCTURE OF A CEMENTLESS MATRIX COMPOSITE BASED ON MECHANICALLY ACTIVATED TECHNOGENIC RAW MATERIALS

2020 ◽  
Vol 11 (1) ◽  
pp. 102-114
Author(s):  
E. V Korneyeva ◽  
G. I Berdov ◽  
S. A Sozinov
Keyword(s):  
Composite Material ◽  
Large Scale ◽  
Raw Materials ◽  
Coal Industry ◽  
Matrix Structure ◽  
Oxide Systems ◽  
Relevant Today ◽  
The Matrix ◽  
Technogenic Raw Materials ◽  
Hardening System

The creation of composite materials using mechanically activated technogenic raw materials is relevant today as part of a large-scale task of construction and technological utilization of technogenic formations. The change in the crystal structure using mechanochemistry increases the activity of technogenic products: the number of coagulation contacts of dissimilar particles increases, increases the plastic strength of the hardening mixture, formation of hydration products is accelerated. The article is devoted to the study of the mechanism of structural and rheological transformations of a cementless hardening system based on activated steelmaking. Steel melting slags were used as raw materials - energy-saturated large-capacity waste of the West-Siberian Metallurgical Combine (Novokuznetsk). As components - activators - waste from the coal industry of the «Abashevskaya» mine (Novokuznetsk) - burnt rocks with heaps and slimes, obtained by neutralization of spent acid battery electrolytes with lime batteries for industrial vehicles. Based on used mechanically activated technogenic raw materials the binder composite material of the matrix structure is obtained. To assess structural and material changes in the hardening system comprehensive physical and chemical studies were carried out: IR - spectroscopy, thermogravimetric and x-ray phase analysis. Electron microscopy investigated the structure of the stone. It was found that the matrix structure of the composite material is a dispersion medium - matrix of dense fine-grained masses calcium sulfate hydrate; dispersed phase from lamellar crystals of quartz and magnesium oxide, and tubular crystals of calcium orthosilicate; and transitional interfacial layer from structured grains of calcium hydrosulfoaluminate. In the process of forming the structure interdependence of phases from each other was accompanied by a sequential transition of some types of structures to others: coagulation→ crystallization- condensation→ crystallization. The article presents the results of the self-organization of the structure, the interaction of oxide systems in the process of hydration is considered, major mineral neoplasms are established, possessing astringent properties and providing strong bonds between structure-forming components.

scholarly journals Using of Technogenic Raw Materials Based on Titanium-containing Slag and Aluminum Bronze for the Development of Composite Material

2020 ◽  
Author(s):  
Mikhail Nikolaevich Zakharov ◽  
Nina Iosifovna Ilinykh ◽  
Olga Vladimirovna Romanova ◽  
Olga Fedorovna Rybalko
Keyword(s):  
Composite Material ◽  
Raw Materials ◽  
Thermodynamic Simulation ◽  
Inert Atmosphere ◽  
Powder Materials ◽  
Aluminum Bronze ◽  
X Ray ◽  
Large Particles ◽  
Technogenic Raw Materials ◽  
Pressing Powder

In this study, the possibility of using of the following technogenic raw materials to obtain a composite material was considered: titanium-containing slag, with the addition of aluminum bronze grade PG-19M-01 (TU 48-4206-156-82) and aluminum powder grade PA-4 (GOST 6058-73). The percentage of components in the mixture were as follows (wt. %): slag - 40, PG-19M-01 - 30, PA-4 - 30. A thermodynamic simulation of the selected system was preliminarily carried out using TERRA program in the temperature range 273 - 4273 K. The chemical and granulometric composition of the initial powders was investigated. From the powder mixture there were compressed the tablets and then they were sintered in an inert atmosphere. Micro-X-ray analysis of sintered samples showed that they consist of large particles of various shapes, most likely containing titanium and iron aluminides, their compounds between themselves and with copper. Keywords: titanium-containing slag, composite material, thermodynamic modeling, intermetallic compounds, pressing, powder materials

Specifics of Structure Formation of Cement Stone with Silica Raw Material - A Substrate of Photocatalytic Composite Material

2021 ◽  
Vol 1017 ◽  
pp. 153-162
Author(s):  
Viktoriya V. Nelyubova ◽  
Yulia N. Ogurtsova ◽  
M.N. Sivalneva ◽  
Valeria V. Strokova ◽  
P. Zhao
Keyword(s):  
Composite Material ◽  
Structure Formation ◽  
Urban Areas ◽  
Raw Materials ◽  
Raw Material ◽  
Cement Matrix ◽  
Cement Stone ◽  
Silica Substrate ◽  
Technogenic Raw Materials ◽  
Quantitative Assessments

The increasing urbanization of urban areas poses the challenge of the development of materials capable of self-cleaning from organic pollutants formed. Previous papers substantiated the possibility of the coating of titanium oxide as the main agent of the photocatalytic method of cleaning structural materials on silica raw materials in order to increase the degree of its distribution in the volume of cement matrix and, as a result, increase its efficiency.It is obvious that a silica substrate will affect the processes of structure formation during hardening of a cement matrix. During the research, the processes of phase transformations of cement stone modified with silica raw materials of natural and technogenic origin were studied. As a result, the influence of siliceous modifiers on the strength characteristics of the cement stone was determined, which allowed ranking them according to the degree of decrease in efficiency as follows: technogenic raw materials; natural raw materials of silicate composition; natural raw materials of aluminosilicate composition. Quantitative assessments of the degree of efficiency showed the irrationality of using aluminosilicate composition as a silica modifier of natural raw materials, which is explained by its low pozzolanic activity.

Investigation of the Decorative Ceramics of Matrix Structure from Iron-Ore Waste with Vanadium Component Addition

2018 ◽  
Vol 931 ◽  
pp. 520-525 ◽  
Author(s):  
Andrey Y. Stolboushkin ◽  
Danil V. Akst
Keyword(s):  
Iron Ore ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Ceramic Materials ◽  
Matrix Structure ◽  
Vanadium Slag ◽  
The Matrix ◽  
Color Form ◽  
Decorative Ceramic ◽  
Component Addition

Results of the study of bulk coloring of decorative ceramic materials with matrix structure based on the slurry part of the iron ore tailings by vanadium slag additive are represented. Chemical, mineralogical and granulometric compositions of the raw materials are presented. The characteristic of their ceramic-technological properties is given. A new method of obtaining decorative ceramic specimens with matrix structure is described. The dependence of physical and mechanical properties and ceramic specimen color form the vanadium slag amount in charge is established. The results of studies of the matrix structure of decorative ceramic specimens with different contents of the coloring additive are represented.

scholarly journals SYNTHESIS AND PROPERTIES OF A COMPOSITE MATERIAL BASED ON COAL MINING WASTE

2020 ◽  
Vol 2 (440) ◽  
pp. 6-13
Author(s):  
A.Kh. Zhakina ◽  
O.V. Arnt ◽  
Ye.P. Vassilets ◽  
Т.S. Zhivotova ◽  
Z.M. Muldahmetov ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Raw Materials ◽  
Waste Product ◽  
Coal Industry ◽  
Proton Acceptor ◽  
Formaldehyde Resin ◽  
Coal Waste ◽  
Natural Polymers ◽  
Sodium Humate

The article presents the results of a study of the synthesis of composite materials based on coal waste combined with coal and polymer raw materials, using ultrasonic chemistry methods and determining the possibility of their use as an active mineral additive for replacing part of cement in fine-grained concrete. By varying the composition of the matrix and the filler, a composite material is obtained whose properties are quantitatively and qualitatively different from the properties of each of its components. As a filler in the composition of the composite material, burned rock is used - the product of oxidative self-firing of waste rock, extracted together with coal to the surface. Burned rocks contain an organic part (unburned carbonaceous impurities) and a mineral part (calcined clay-sandy part). Features of the material composition of burned rocks, coal industry waste allows us to consider them as secondary mineral raw materials. The binder in the composite material used is thiourea-formaldehyde resin. The resin was obtained by the standard method of polycondensation of thiourea with formaldehyde at a molar ratio of thiocarbamide:formaldehyde = 1:2. The choice of thiourea-formaldehyde resin is due to the availability, water solubility and the presence of a sufficient number of proton acceptor centers capable of complexation with a modifier. The modifier for composite materials used a coal waste product related to promising natural polymers in nanotechnology, sodium humate, extracted by alkaline extraction from oxidized coal from the Shubarkol deposit. Sodium humate refers to polyfunctional polymers with a unique combination of hydrophobic and hydrophilic sites, a variety of oxygen-containing functional groups, aromatic, heterocyclic and other groups. All this suggests a high ability of sodium humate to intermacromolecular interactions with both the burned rock and thiourea-formaldehyde resin. Composite material based on burned rock, sodium humate with thiourea-formaldehyde resin was synthesized by impregnation using ultrasonic treatment. The decisive role of ultrasonic activation is shown and the effectiveness of its application to the process of producing composites is noted. The modern physicochemical and physicomechanical methods have characterized the composition and structure of the obtained composite materials. The mineralogical composition of composite materials was studied using x-ray phase analysis, and surface morphology based on microscopic analysis using a scanning electron microscope. Filling the composite material with burnt rock provides higher physical and mechanical properties. The strength of burnt-filled composites is higher than that of samples of a similar composition without burnt rock. The resulting composite can be used as a building material. Key words: composite material, filler, binder, burned rock, thiourea-formaldehyde resin.

Research of Composite Material Properties Based on Waste Glass and Scrap Aluminum

2012 ◽  
Vol 468-471 ◽  
pp. 2868-2871 ◽  
Author(s):  
Jin Zhou Zhang
Keyword(s):  
Wear Resistance ◽  
Composite Material ◽  
Material Properties ◽  
Raw Materials ◽  
Waste Glass ◽  
Mechanical Mixing ◽  
Aluminum Composite ◽  
The Matrix ◽  
Mixing Method ◽  
Scrap Aluminum

Considered waste glass and scrap aluminum as raw materials, preparation of waste glass and scrap aluminum composite materials by using mechanical mixing method. Composite material properties were studied by experiments. With the increase of the glass particles, the composite tensile strength and hardness are improved, wear resistance is increased much more than the matrix, it provides useful help of the use of waste.

Formation of Persistent Slip Band in Fatigued Copper Single Crystals

1982 ◽  
Vol 40 ◽  
pp. 470-471
Author(s):  
N. Y. Jin
Keyword(s):  
Volume Fraction ◽  
Fatigue Cracks ◽  
Wall Structure ◽  
Matrix Structure ◽  
Dislocation Dipole ◽  
Slip Bands ◽  
Persistent Slip Bands ◽  
The Matrix ◽  
Hard Shell ◽  
Copper Single Crystals

Localised plastic deformation in Persistent Slip Bands(PSBs) is a characteristic feature of fatigue in many materials. The dislocation structure in the PSBs contains regularly spaced dislocation dipole walls occupying a volume fraction of around 10%. The remainder of the specimen, the inactive "matrix", contains dislocation veins at a volume fraction of 50% or more. Walls and veins are both separated by regions in which the dislocation density is lower by some orders of magnitude. Since the PSBs offer favorable sites for the initiation of fatigue cracks, the formation of the PSB wall structure is of great interest. Winter has proposed that PSBs form as the result of a transformation of the matrix structure to a regular wall structure, and that the instability occurs among the broad dipoles near the center of a vein rather than in the hard shell surounding the vein as argued by Kulmann-Wilsdorf.

The microstructure of a TiB2/Ti-47 Al composite material

1989 ◽  
Vol 47 ◽  
pp. 674-675
Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz
Keyword(s):  
Composite Material ◽  
Ion Beam ◽  
Chemical Properties ◽  
Intermetallic Alloys ◽  
Transmission Electron ◽  
Diamond Polishing ◽  
Al Composite ◽  
The Matrix ◽  
Argon Ion ◽  
And Chemical Properties

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.

The sugar and alcohol industry in the biofuels and cogeneration era: a paradigm change (part II)

2014 ◽  
pp. 97-104 ◽  
Author(s):  
Electo Eduardo Silv Lora ◽  
Mateus Henrique Rocha ◽  
José Carlos Escobar Palacio ◽  
Osvaldo José Venturini ◽  
Maria Luiza Grillo Renó ◽  
...  
Keyword(s):  
Large Scale ◽  
New Technologies ◽  
Process Integration ◽  
Animal Feed ◽  
Raw Materials ◽  
Biofuel Production ◽  
New Paradigm ◽  
Alcohol Industry ◽  
Feed Production ◽  
Steam Parameters

The aim of this paper is to discuss the major technological changes related to the implementation of large-scale cogeneration and biofuel production in the sugar and alcohol industry. The reduction of the process steam consumption, implementation of new alternatives in driving mills, the widespread practice of high steam parameters use in cogeneration facilities, the insertion of new technologies for biofuels production (hydrolysis and gasification), the energy conversion of sugarcane trash and vinasse, animal feed production, process integration and implementation of the biorefinery concept are considered. Another new paradigm consists in the wide spreading of sustainability studies of products and processes using the Life Cycle Assessment (LCA) and the implementation of sustainability indexes. Every approach to this issue has as an objective to increase the economic efficiency and the possibilities of the sugarcane as a main source of two basic raw materials: fibres and sugar. The paper briefly presents the concepts, indicators, state-of-the-art and perspectives of each of the referred issues.

scholarly journals Synthesis of Metal Organic Frameworks by Ball-Milling

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Cheng-An Tao ◽  
Jian-Fang Wang
Keyword(s):  
Ball Milling ◽  
Large Scale ◽  
Raw Materials ◽  
Metal Organic Frameworks ◽  
Research Topic ◽  
Mass Ratio ◽  
Time Consumption ◽  
Metal Organic ◽  
Short Time ◽  
Made In

Metal-organic frameworks (MOFs) have been used in adsorption, separation, catalysis, sensing, photo/electro/magnetics, and biomedical fields because of their unique periodic pore structure and excellent properties and have become a hot research topic in recent years. Ball milling is a method of small pollution, short time-consumption, and large-scale synthesis of MOFs. In recent years, many important advances have been made. In this paper, the influencing factors of MOFs synthesized by grinding were reviewed systematically from four aspects: auxiliary additives, metal sources, organic linkers, and reaction specific conditions (such as frequency, reaction time, and mass ratio of ball and raw materials). The prospect for the future development of the synthesis of MOFs by grinding was proposed.

scholarly journals On Randomized Trace Estimates for Indefinite Matrices with an Application to Determinants

2021 ◽  
Author(s):  
Alice Cortinovis ◽  
Daniel Kressner
Keyword(s):  
Large Scale ◽  
Gaussian Process Regression ◽  
Likelihood Estimation ◽  
Random Vectors ◽  
Symmetric Positive Definite ◽  
Matrix Logarithm ◽  
The Matrix ◽  
Trace Estimation ◽  
Scale Matrix ◽  
Existing Result

AbstractRandomized trace estimation is a popular and well-studied technique that approximates the trace of a large-scale matrix B by computing the average of $$x^T Bx$$ x T B x for many samples of a random vector X. Often, B is symmetric positive definite (SPD) but a number of applications give rise to indefinite B. Most notably, this is the case for log-determinant estimation, a task that features prominently in statistical learning, for instance in maximum likelihood estimation for Gaussian process regression. The analysis of randomized trace estimates, including tail bounds, has mostly focused on the SPD case. In this work, we derive new tail bounds for randomized trace estimates applied to indefinite B with Rademacher or Gaussian random vectors. These bounds significantly improve existing results for indefinite B, reducing the number of required samples by a factor n or even more, where n is the size of B. Even for an SPD matrix, our work improves an existing result by Roosta-Khorasani and Ascher (Found Comput Math, 15(5):1187–1212, 2015) for Rademacher vectors. This work also analyzes the combination of randomized trace estimates with the Lanczos method for approximating the trace of f(B). Particular attention is paid to the matrix logarithm, which is needed for log-determinant estimation. We improve and extend an existing result, to not only cover Rademacher but also Gaussian random vectors.

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