scholarly journals INVESTIGATIONS OF LOW-CEMENT CASTABLES WITH SHAMOTTE AGGREGATE/MAŽACEMENČIO KAITRAI ATSPARAUS BETONO SU ŠAMOTO UŽPILDU TYRIMAI

1999 ◽  
Vol 5 (1) ◽  
pp. 32-35
Author(s):  
Stasys Goberis ◽  
Liutauras Merlinskaja ◽  
Ina Pundienė
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
High Water ◽  
Furnace Lining ◽  
High Water Absorption ◽  
Cold Crushing Strength ◽  
Normal Quantity ◽  
Shock Resistance

The castables with low-cement and normal quantity cement in its composition physical and mechanical properties was investigated. Aggregates of recycled shamotte waste, which are characterised by high water absorption, were used for castables. The results of influence of firing temperature on density and cold crushing strength for three series castables were determined (Fig 1 and 2). Thermal shock resistance, bending strength and deformations of the castables were investigated additionally (Table 2 and Fig 4). The results of investigations showed the advantage of low-cement castables: better thermal shock resistance, higher cold crushing and bending strength after firing at high temperature. The properties of developed low-cement and traditional castables produced with schamotte waste aggregates were compared with the data from German, Danish and Polish castables, a special quality shamotte aggregate was used (Table 1). Low-cement castable based on shamotte waste aggregates were developed and used for producing “Ipsen” furnace lining items.

Preparation of ZrO2 Composite Ceramics with High Thermal Shock Resistance

2012 ◽  
Vol 455-456 ◽  
pp. 650-654 ◽  
Author(s):  
He Yi Ge ◽  
Jian Ye Liu ◽  
Xian Qin Hou ◽  
Dong Zhi Wang
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Sintering Temperature ◽  
Fiber Composite ◽  
Physical And Mechanical Properties ◽  
Composite Ceramics ◽  
Shock Resistance ◽  
Absorption Measurements

The physical and mechanical properties of nanometer ZrO2-ZrO2fiber composite ceramics were studied by introduction of ZrO2fiber. ZrO2composite ceramics at different sintering temperature was investigated by porosity and water absorption measurements, flexual strength and thermal shock resistance analysis. Results showed that ZrO2composite ceramics containing 15 wt% ZrO2fiber with sintering temperature of 1650°C exhibited good mechanical properties and thermal shock resistance. The porosity and the water absorption were 8.84% and 1.62%, respectively. The flexual strength was 975 MPa and the thermal shock times reached 31 times. Scanning electron microscope (SEM) was used to analyze the microstructure of ZrO2composite ceramics.

The Limitation of Evaluating Thermal Shock Resistance of Al2O3-SiO2 Refractory by Measuring Strength Loss Rate

2011 ◽  
Vol 295-297 ◽  
pp. 2309-2313
Author(s):  
Xin Liu ◽  
Dian Li Qu ◽  
Zhi Jian Li
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Loss Rate ◽  
Strength Loss ◽  
X Ray Diffraction ◽  
Initial State ◽  
X Ray ◽  
Cold Crushing Strength ◽  
Shock Experiment ◽  
Shock Resistance

This paper deeply studied the limitation of evaluating the thermal shock resistance of Al2O3-SiO2 refractory by measuring Strength Loss Rate (SLR). By means of supersonic, X-ray diffraction (XRD), the results were drawn as followed.1)After the thermal shock experiment for mullite based A-S refractory, which were composed by mullite and corundum, the supersonic velocity slowed down as it going through the sample while the cold crushing strength abnormally increased at initial state.2) The strength increased remarkably with the ascending of mullite fraction.3)It is inadequate to evaluate the thermal shock resistance of mullite based A-S refractory by strength loss rate.

scholarly journals Influence of an addition amount of a new type of alumina on the properties of ramming mullite-corundum mixes and samples from them

2020 ◽  
Vol 120 ◽  
pp. 66-82
Author(s):  
V. V. Primachenko ◽  
I. G. Shulik ◽  
I. V. Khonchik ◽  
T. G. Tishina
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Chemical Properties ◽  
Size Composition ◽  
Synthesis Process ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance ◽  
Spherical Alumina ◽  
Addition Amount

Effect investigation of an addition amount of spherical alumina on the properties of ramming mullite-corundum mixes of the MMK-90 (on a binder of an aqueous solution of orthophosphoric acid) and MMKPBF (with a MgO addition on a borophosphate binder) brands, as well as samples from them, have been carried out. As a result of the carried out studies, it was found that the use of an optimal amount (4 %) of spherical alumina in the composition of ramming mullite-corundum mixes provides an increase in by 30 % in the cold crushing strength of samples made from them, fired at a temperature of 1580 °C, while maintaining at sufficiently high level indicators of their thermal shock resistance and slag resistance. The indicated alumina use in the composition of the MMK-90 mix during high-temperature firing of samples leads to an intensification of the mullite synthesis process. In fired samples from the MMKPBF mix, the spherical alumina forms a dense intergrowth of "felt-like" structure, which reinforces the structure, increasing the strength and thermal shock resistance of the samples. Indicators of physical and chemical properties of ramming mullite-corundum mixes of improved composition and samples made from them (for MMK-90 and MMKPBF mixes, respectively): chemical composition, wt. %: Al2O3 — not less than 90.0 and 85.0; SiO2 — within 3.2-5.0 and no more than 2.5; Fe2O3 — no more than 1.0 and 0.6; P2O5 — in the range of 2.5-3.5 and 0.5-1.0; grain size composition, mm — 3-0; cold crushing strength after firing at a temperature of 1580 °С — 110 and 70 N/mm2; thermal shock resistance — > 20 thermal cycles 950 °С — water. Ramming mullite-corundum mixes of improved composition are recommended for use in various heating units with high specific mechanical loads on the lining.

scholarly journals High Temperature Bending Strength and Thermal Shock Resistance of Carbon-Ceramics Composites

TANSO ◽  
1985 ◽  
Vol 1985 (120) ◽  
pp. 21-27 ◽  
Author(s):  
Kenji Miyazaki ◽  
Hisayoshi Yoshida ◽  
Kazuo Kobayashi
Keyword(s):  
High Temperature ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Shock Resistance

Thermal Shock Resistance of ZrO2 Fiber/Al2O3 Ceramics

2011 ◽  
Vol 306-307 ◽  
pp. 754-757 ◽  
Author(s):  
Xian Qin Hou ◽  
Jian Ye Liu ◽  
He Yi Ge
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Water Absorption ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Shock Resistance ◽  
Scanning Electron ◽  
Absorption Measurements

The physical and mechanical properties of alumina (Al2O3) ceramics by introduction of zirconia (ZrO2) fiber were studied. ZrO2/Al2O3ceramics at different sintering temperature was investigated by porosity and water absorption measurements, flexual strength and thermal shock resistance analysis. Results showed that Al2O3 ceramics containing 15 wt% ZrO2fiber with sintering temperature of 1650°C exhibited good mechanical properties and thermal shock resistance. The porosity and water absorption were 7.4% and 0.69%, respectively. The flexual strength was 613 MPa and the thermal shock times reached 29 times. Scanning electron microscope (SEM) was used to analyze the microstructure of Al2O3 ceramics.

Optimizing Performance of Magnesia-Spinel Brick Used at Cement Rotary Kiln

2011 ◽  
Vol 250-253 ◽  
pp. 588-594 ◽  
Author(s):  
Dong Wang ◽  
Yong Li ◽  
Yang Li ◽  
Rui Li ◽  
Yue Li
Keyword(s):  
Grain Size ◽  
Thermal Shock ◽  
Rotary Kiln ◽  
Thermal Shock Resistance ◽  
Raw Material ◽  
Crushing Strength ◽  
Magnesia Spinel ◽  
Cold Crushing Strength ◽  
Comprehensive Performance ◽  
Shock Resistance

Using high pure magnesia and magnesia-spinel as the main raw material, keeping the same quantity of spinel, specimens were made with different spinel size distribution (≤0.044mm, 1-0mm, 2-1mm, 3-2mm and 3-1mm). Dextrin and brine are the binder. Specimens were dried at the temperature of 110°C for 24 hours, sintered at the temperature of 1680°C holding 8 hours in a tunnel kiln. The properties and microstructure of the specimens were analyzed. The results are shown that the addition of spinel with grain size of 3-1mm improves sintering of magnesia-spinel brick, with the thermal shock resistance reaching 18 cycles, the cold crushing strength reaching 54 MPa, improving the comprehensive performance of the magnesia-spinel brick.

scholarly journals EVALUATION AND CHARACTERIZATION OF GAKEM AND ABOUCHICHE CLAY SAMPLES IN BEKWARRA LGA OF CROSS RIVER STATE FOR USE AS REFRACTORY MATERIALS

2017 ◽  
Vol 36 (3) ◽  
pp. 844-848
Author(s):  
FA Ovat ◽  
DE Ewa ◽  
EA Egbe
Keyword(s):  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Linear Shrinkage ◽  
Apparent Porosity ◽  
Refractory Materials ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance

The characterization of some clay as refractory materials for furnace lining has become relevant to find solutions to the cost involved in the purchase and importation of these refractory materials. This work investigated the refractory properties of clay samples for their suitability for use in the industries. Clay samples were collected from Gakem and Abouchiche areas and analysed for physical and chemical properties to determine the suitability of the clays as refractory materials. The results showed cold crushing strength (21.46MN/m2), thermal shock resistance (27 cycles), bulk density (3.52g/cm3), linear shrinkage(3.80%), apparent porosity (28.84%) and permeability (80%) for Gakem; and cold cold crushing strength (18.40MN/m2), thermal shock resistance (25 cycles), bulk density(2.81g/cm3), linear shrinkage (3.70%), apparent porosity (25.86%) and permeability (77%) for Abouchiche respectively. The chemical compositions of these clay samples were also investigated. The results showed that the samples fall under Aluminosilicate type of clay because of their high values of Aluminium Oxide and Silicon Oxide. Tests showed that clay from these areas can be used to produce refractory materials that can withstand a furnace temperature of about 1600°C. http://dx.doi.org/10.4314/njt.v36i3.26

Effect of Gezawa Clay on the Properties of Silica Stone for Refractory Brick

2013 ◽  
Vol 315 ◽  
pp. 11-14 ◽  
Author(s):  
I.A. Rafukka ◽  
B. Onyekpe ◽  
Y. Tijjani
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Apparent Porosity ◽  
Chemical Compositions ◽  
Refractory Brick ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance ◽  
Made In ◽  
Fire Clay

The investigations centered on how addition of Gezawa clay (GC) affects the refractory properties of the Gezawa stone (GS) (Silica Stone) with a view to finding the optimum percentage of the blend that will give good refractory properties. The samples were crushed, ground, sieved and the chemical compositions were determined. Test samples were produced by blending the Gezawa stone with various proportions of Gezawa clay. The refractoriness of the samples was measured, and the samples were then fired to 1100and standard properties such as thermal shock resistance, cold crushing strength and apparent porosity were determined. The result shows that addition of Gezawa clay to Gezawa stone improves its thermal shock resistance but reduces the refractoriness, while the porosity was found to be within the specified range for fire clay and the cold crushing strength of the samples was high. Compromise could be made in selecting the percentage that would suit certain application.

Influence of Additives on Performance of Silicon Carbide Refractory

2012 ◽  
Vol 538-541 ◽  
pp. 2277-2280
Author(s):  
You Fu Guo ◽  
Ming Yue Zheng ◽  
Jing Long Bu ◽  
Yue Jun Chen ◽  
Li Xue Yu ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Thermal Expansion ◽  
Bulk Density ◽  
Thermal Shock ◽  
Silica Fume ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Carbide Refractory ◽  
Shock Resistance ◽  
Silicon Carbide Refractory

Silicon carbide with diffierent granularity was used as raw material, quartz, silica fume, aluminum powder or alumina was used as additive with dosages of 1% (in mass, similarly hereinafter), 3% and 5%. Silicon carbide refractory material was prepared in oxidizing atmosphere at 1400 °C for 3 h. Performence of samples were researched by measurements of apparent porosity, bulk density, bending strength at room temperature, thermal shock resistance and thermal expansion rate, and analyzed by SEM. The results showed that samples added silica fume have low thermal expansion rate and apparent porosity, high bending strength and bulk density, good thermal shock resistance, compact texture as well. It can be deduced that 5% silica fume plays the excellent role to improve integrated performance of silicon carbide refractory material.

Microstructure and Thermal Shock Behaviour of Alumina Composite Ceramic for Heat Transmission Pipeline

2014 ◽  
Vol 692 ◽  
pp. 217-223 ◽  
Author(s):  
Xiao Hong Xu ◽  
Xiao Yang Xu ◽  
Jian Feng Wu ◽  
Yang Zhou ◽  
De Zhi He
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Raw Materials ◽  
Composite Ceramic ◽  
Alumina Powder ◽  
Monoclinic Zirconia ◽  
Heat Transmission ◽  
Transmission Pipeline ◽  
Shock Resistance

Al2O3 composite ceramics materials used for heat transmission pipeline were prepared by pressureless sintering in air. Calcined bauxite, talc and commercial alumina powder were used as the main raw materials, partially stabilized zirconia was also added to improve the thermal shock resistance of the samples. The effects of composition and sintering temperature on density, phase composition, microstructure and thermal shock behavior of samples were evaluated. It shows that the B2 sample which was sintered at 1400 °C for 2 h has optimal properties with porosity 0.4%, bulk density 3.2 g•cm-3.The bending strength increases 19.46 MPa after 30 times thermal shock cycles from 1100 °C to room temperature. The main phases of B2 are corundum and spinel, meanwhile, a small amount of monoclinic zirconia and α-quartz are also detected according to XRD pattern. Microstructure analysis reveals that spinel crystals are interlocked by prismatic corundum crystals, bright white beaded monoclinic zirconia particles are distributed uniformly, and it is beneficial to improve the thermal shock resistance of sample.

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