scholarly journals PERICLASE-SPINEL REFRACTORY MODIFIED ТІО2

2021 ◽  
pp. 9-14
Author(s):  
Oksana Borysenko ◽  
Sergii Logvinkov ◽  
Halyna Shabanova ◽  
Igor Ostapenko ◽  
Olena Gaponova
Keyword(s):  
Solid Phase ◽  
Gas Permeability ◽  
Physical And Mechanical Properties ◽  
Structural Effect ◽  
Cement Clinker ◽  
High Alumina ◽  
Adaptation Mechanism ◽  
Spinel Refractory ◽  
Initial Charge ◽  
Rotary Kilns

Over the past decades, the development and improvement of refractory materials for lining high-temperature zones of rotary kilns continues. The main requirements for refractory products for lining rotary kilns for cement clinker roasting are: high density and ultimate compressive strength, low porosity and gas permeability, increased abrasion resistance, low thermal conductivity, high corrosion resistance and the ability to form a protective layer.Today, the main goal of modern researchers is to create a heat-resistant refractory with a flexible structure that ensures its integrity at high temperatures and mechanical loads, which have the ability to form a protective coating layer. In this work, a technological approach has been tested for introducing a vibro-milled modifier (briquette based on a high-alumina component and a titanium-containing additive) into the composition of the raw charge for periclase-spinel refractory in the form of a pre-synthesized product containing crystalline phases of the Al2O3 – TiO2 – FeO system. The basis for the production of periclase-spinel refractories modified with TiO2 is the four-component system MgO – Al2O3 – FeO – TiO2, on the basis of thermodynamic calculations of which the content of individual components of the charge was selected and the operational characteristics were predicted. The interrelation of physical and mechanical properties with the content of individual components in the initial charge warehouses is shown, and the directions of solid-phase processes with their participation are noted. The features of the microstructure of the sample material are noted in relation to the formation of an optimal set of properties. It is shown that the nature of the organization of micropores is favorable for increasing the thermal stability of the material, which complements the phase adaptation mechanism also with the structural effect of damping mechanical stresses during thermal cycling.

Thermodynamics of Solid-Phase Exchange Reactions Limiting the Subsolidus Structure of the System MgO-Al2O3-FeO-TiO2

2021 ◽  
Vol 1038 ◽  
pp. 177-184
Author(s):  
Oksana Borisenko ◽  
Sergey Logvinkov ◽  
Galina Shabanova ◽  
Oksana Myrgorod
Keyword(s):  
Materials Science ◽  
Solid Phase ◽  
Structural Materials ◽  
The State ◽  
Cement Clinker ◽  
Multicomponent Systems ◽  
Exchange Reactions ◽  
Chemical Corrosion ◽  
Physicochemical Basis ◽  
Rotary Kilns

The basis of modern materials science is multicomponent systems, on their basis it is possible to create various combinations of phases in structural materials with a set of specified properties. The investigated system MgO-Al2O3-FeO-TiO2 is promising for the production of periclase-spinel refractories used as lining of rotary kilns during cement clinker firing, which are highly resistant to chemical corrosion when exposed to a gas environment and cement clinker components; thermomechanical stresses. However, in the reference literature and scientific articles, no information was found on the structure of the four-component diagram of the state of the MgO-Al2O3-FeO-TiO2 system, partial elements of its structure are given only in the composition of multicomponent systems [1-3]. Thus, research to the study of the subsolidus structure of the MgO-Al2O3-FeO-TiO2 system, which is the physicochemical basis for the development of compositions of periclase-spinel refractories, is urgent.

Production of high-alumina cement clinker by fusion in an electric furnace

Refractories ◽  
1984 ◽  
Vol 25 (5-6) ◽  
pp. 293-296 ◽  
Author(s):  
I. N. Sorokin ◽  
T. M. Golovina ◽  
D. S. Rutman ◽  
A. D. Popov ◽  
V. M. Ust'yantsev ◽  
...  
Keyword(s):  
Electric Furnace ◽  
Cement Clinker ◽  
High Alumina ◽  
Alumina Cement ◽  
High Alumina Cement

scholarly journals THE EFFECT OF SODIUM SILICATE AND ITS SOLUTION ON THE PROPERTIES OF REFRACTORY COMPLEX BINDER/NATRIO SILIKATO KIEKIO IR JO TIRPALO TANKIO ĮTAKA KOMPLEKSINIO KAITRAI ATSPARAUS RIŠIKLIO SAVYBĖMS

1999 ◽  
Vol 5 (3) ◽  
pp. 211-216
Author(s):  
Valentin Antonovič ◽  
Stasys Goberis ◽  
Romualdas Mačiulaitis
Keyword(s):  
Sodium Silicate ◽  
Liquid Glass ◽  
Solid Phase ◽  
Physical And Mechanical Properties ◽  
Alumina Cement ◽  
Hardening Mechanism ◽  
Temperature Range ◽  
Calcium Hydrosilicates ◽  
Higher Temperature ◽  
Complex Binder

In order to improve thermal and mechanical characteristics of a traditional binder with liquid glass a complex binder consisting of liquid glass, its hardener and alumina cement (“Gorkal 70” containing not less than 70 per cent of AI2O3) was tested. Sodium silicate and its solution effect on physical and mechanical properties of a new refractory complex binder (Table 1, Fig 2) were investigated. The results obtained show that compressive strength of binding compound with high quantity of sodium silicate (N3) is the lowest after it had been cured, dried and fired at 300–600°C (Fig 3). It was also found that the strength of a complex binder with small quantity of sodium silicate (N1) in the temperature range of 20–600°C is 2–3 times as high as that of a traditional binder with dispersed fire-clay. The study in the formation of the structure of a complex binders dilatometric tests have also been made. After initial heating at 80–500°C the compositions contracted (Fig 4) due to dehidratation. At the temperature range of 580–750°C the contraction of compositions continue due to reactions at the solid phase. The hypothesis of the hardening mechanism in the complex binder was proposed. Liquid glass tends to restrain the hydration of the alumina cement though hardeners and sodium silicate interaction result in the intense formation of sodium calcium hydrosilicates. Therefore, a complex binder contains less sodium silicate than a traditional one while being used at higher temperature.

Process of Shaped Metal Billets Production from Compositions Based on Iron Powder, Iron Oxide, and Binder

2017 ◽  
Vol 265 ◽  
pp. 250-258
Author(s):  
V.A. Dovydenkov ◽  
O.S. Zvereva ◽  
S.Ya. Alibekov
Keyword(s):  
Iron Oxide ◽  
Thermal Treatment ◽  
Solid Phase ◽  
New Technology ◽  
Physical And Mechanical Properties ◽  
Dimensional Accuracy ◽  
Uniform Density ◽  
Protective Medium ◽  
Experimental And Theoretical Studies ◽  
Mim Technology

A new technology of metal billets production by molding and thermal treatment of compositions based on iron powders of medium dispersion, fine powders of iron oxide, and the thermosetting binder, which provides for the required physical and mechanical properties of the material, is proposed. It is found that, at a certain concentration and dispersion of the components of the solid phase, the injection and direct compression molding of parts of complex shape (similar to the MIM-technology) is possible at pressures from 70 MPa to 100 MPa ensuring uniform density over the cross section. The established stages of thermal treatment of compositions, thermal behavior and protective medium ensuring uniformity of products, and chemical composition of the product material are presented in the paper. The experimental and theoretical studies of the dimensional accuracy of steel products obtained by the developed technology were carried out, and it was discovered that the produced parts were of the precision of steel parts produced by MIM-technology.

Nano Titania Reinforced Limestone Cement: Physico-Mechanical Investgation

2018 ◽  
Vol 786 ◽  
pp. 248-257
Author(s):  
Mohmoud A. Abuelseoud ◽  
Asmaa S. Hamouda ◽  
Ibrahim M. Ismail ◽  
M.A. El-Sheikh
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Cement Clinker ◽  
Titanium Silicate ◽  
Cement Pastes ◽  
Limestone Cement

Studying physical and mechanical properties of limestone cement pastes blended by TiO2 nanoparticles (i.e., particle size less than 100 nm). Three mixes are prepared for this study (5.00, 10.00 and 25.00 wt. % of limestone) partially replaced cement/clinker by TiO2 nanoparticles. Fillers are carefully selected which reinforcing cement workability or water retention they could be inert or have slightly hydraulic properties. Limestone is most common filler that fills the pores between cement particles due to the formation of monocarboaluminate, while nanoparticles increase the hydration C-S-H gel product and calcium titanium silicate which hardened the cement pastes. Nanoparticles show a great effect in reinforcing the mechanical strength of cement pastes due to the fact that TiO2-nanoparticles act as active nuclei site forming C-S-H gel observed as honeycomb-like plus improving cement to water demined (W/C) ratio. SEM analysis proves that the morphology of cement structure is well arranged and compacted.

A Study on Structure and Phase Composition of Cellular Ceramic Materials from Dispersed Silica-Rich Rocks

2018 ◽  
Vol 284 ◽  
pp. 893-898
Author(s):  
Andrey Yu. Stolboushkin ◽  
A.I. Ivanov ◽  
O.A. Fomina
Keyword(s):  
Phase Composition ◽  
Cellular Structure ◽  
Solid Phase ◽  
Foam Glass ◽  
Physical And Mechanical Properties ◽  
Ceramic Materials ◽  
Average Density ◽  
Crystalline Material ◽  
Pore Glass ◽  
Cellular Ceramic

Studies on structure, phase composition and properties of ceramic wall materials with a glass-crystalline framework from dispersed silica-rich rocks are described. The results of chemical, mineralogical and granulometric compositions of tripolite and granulated foam-glass crystalline material (GFGCM) are presented. The dependence of physical and mechanical properties of cellular ceramic materials on GFGCM content in the composition in the amount from 5 to 75% is determined. Test samples of cellular ceramic materials with dimensions 250 × 120 × 65 mm, having a compressive strength 16.2-20.8 MPa, water absorption 7.1-7.9 % and an average density 0.99-1.32 g/m3 were produced at the factory. At the macroscale level the cellular structure of the ceramic material consists of closed pores with a vitrified inner surface pore, glass-crystalline outer shell of the pores and solid phase of the framework walls. It was established that after firing in the temperature range 850-900 °C the walls of the framework are represented by quartz, feldspar and hematite, a pronounced halo is indicating a significant amount of glass phase.

Influence of Acid Soil Stabilizer on the Acid-Basic Properties of Drill Cuttings

2019 ◽  
Vol 23 (10) ◽  
pp. 29-33
Author(s):  
L.V. Rudakova ◽  
E.A. Pichugin ◽  
M.V. Zilberman ◽  
E.V. Zyryanova
Keyword(s):  
Building Materials ◽  
Solid Phase ◽  
Acid Soil ◽  
Physical And Mechanical Properties ◽  
Environmental Safety ◽  
Engineering Structures ◽  
Drill Cuttings ◽  
Road Building ◽  
Physicomechanical Characteristics ◽  
Soil Stabilizer

One of the most promising areas of disposal of drill cuttings is their use as a component for the manufacture of mixtures used for the construction of engineering structures, such as road foundations. One of the limitations of the disposal of drill cuttings in this direction is the presence of alkaline components in the slimes, which worsen the physicomechanical characteristics of the mixtures obtained and create the threat of negative environmental impacts. In this article, the authors studied the dynamics of changes in the pH of the slurry sludge-water, and also conducted experiments to study the effects of additions of hydrochloric acid and acid soil stabilizer Polybond. It was established that the buffering capacity of the solid phase of drill cuttings in relation to maintaining pH at a level exceeding the value of 9 is low, and maintaining pH = 6÷8 units. is high. This fact suggests that when obtaining road-building mixtures based on drill cuttings, it is possible to do with small additions of acid soil stabilizer, at the same time the risk of obtaining products with unacceptably low pH values is negligible. The use of acid soil stabilizer in the manufacture of road-building materials based on drilling sludge helps ensure environmental safety of products, as well as improve the physical and mechanical properties of the material.

scholarly journals Silicon carbide liquid-phase sintering with various activating agents

2018 ◽  
pp. 24-30
Author(s):  
S. N. Perevislov ◽  
M. V. Tomkovich ◽  
A. S. Lysenkov
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Liquid Phase ◽  
Mechanical Characteristics ◽  
Solid Phase ◽  
Physical And Mechanical Properties ◽  
Liquid Phase Sintering ◽  
Sintered Materials

The liquid-phase sintering at 1860‒2100 °C was used to prepare the silicon-carbide materials with the 5‒10 weigh percent of oxide additions. The SiC material with the 20 weigh percent of three-component MgO‒Y2O3‒Al2O3system addition showed the ultimate physical and mechanical properties. The mechanical characteristics of the liquidphase sintered materials with the 15 weigh percent of the three-component oxides addition exceed those of both the reactive-sintered and the solid-phase sintered materials and approach to those of the hot-pressed materials.Ill. 5. Ref. 31. Tab. 2.

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