Aluminum titanate was in-situ synthesized by using industrial waste-residue in the aluminum factory and TiO2 as the main raw materials and the influence of different reaction temperatures on the purity and microstruct...Aluminum titanate was in-situ synthesized by using industrial waste-residue in the aluminum factory and TiO2 as the main raw materials and the influence of different reaction temperatures on the purity and microstructures of synthesized products were mainly discussed. The obtained Al2TiO5 was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and relevant analytical software. The results show that elevating the sintering temperature can increase the content of aluminum titanate; and at 1420 ℃, it reaches the highest in the synthesized ceramic. When the sintering temperature continues to increase, the produced aluminum titanate will decompose resulting in the drop of its content. Therefore, the optimum sintering temperature of in-situ synthesis of aluminum titanate is determined as 1420 ℃, at which the grains of aluminum titanate grow completely, the purity of aluminum titanate is 89.3wt%., the highest density is 2.75 g/cm^3, and the porosity is 9%.展开更多
By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The e...By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.展开更多
The influence of Fe2O3 impurity on the crystalline structure of cordierite synthesized from waste aluminum slag is discussed. XRD and SEM techniques were employed to characterize the crystalline structure and micros...The influence of Fe2O3 impurity on the crystalline structure of cordierite synthesized from waste aluminum slag is discussed. XRD and SEM techniques were employed to characterize the crystalline structure and microstructure of each specimen. Philips X’pert plus software was used to determine the lattice parameters of each specimen. The results show that the Fe2O3 content of 0.8～1.6wt% is beneficial to the formation of cordierite, with the cordierite amount reaching 90wt%. So 0.8～1.6wt% is considered as the allowable Fe2O3 content in the specimens and 0.8wt% is determined to be the best after overall analysis. Plus software analysis shows that the cordierite in each specimen has the same symmetrical hexagonal structure as the single crystal, and the lattice parameters as well as the lattice dimensions change slightly.展开更多
Waste aluminum slag and oyster shell were used as raw materials to synthesize calcium hexaluminate（CA6）. The effects of different source materials of CaO and sintering temperature on the structures and properties of...Waste aluminum slag and oyster shell were used as raw materials to synthesize calcium hexaluminate（CA6）. The effects of different source materials of CaO and sintering temperature on the structures and properties of CA6 were investigated,respectively. The results show that compared to calcium oxide,oyster shell can lower the formation temperature of CA6,hence CA6 can be detected at 1300 ℃ by using oyster shell as the starting raw materials. Increasing the sintering temperature can promote the crystal growth. CA6 crystals show typical platelet shape,and its optimum sintering temperature falls in the 1450～1550 ℃ region. The bulk density is 1.54～1.83 g/cm^3,the apparent porosity is 44.1～55.2% and the flexural strength is 10.8～25.3 MPa.展开更多
By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The e...By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.展开更多
In order to explore the relationship between the macroscopic properties and pore structure characteristics of baking-free slag-sludge bricks,the compressive strength and water absorption rate using aluminum industrial...In order to explore the relationship between the macroscopic properties and pore structure characteristics of baking-free slag-sludge bricks,the compressive strength and water absorption rate using aluminum industrial slag and sludge of different substitution rates were tested.Optical instruments and image analysis software were used to measure the parameters of the pore structure.Specifically,a fractal model was built based on the fractal theory,in which the fractal dimension was used as the characteristic index of the pore structure to analyze the correlation and interaction mechanism between the fractal dimension and the macroscopic mechanical properties.Based on this study,conclusions were drawn as follows:(1)The plane pore structure of baking-free bricks shows good fractal characteristics.With the increase of the aluminum industrial slag content,the fractal dimension becomes smaller and the pore structure develops well;with the increase of the sludge content,the fractal dimension becomes larger and the pore structure becomes worse;(2)As the fractal dimension of the plane pore structure increases,the compressive strength of baking-free bricks falls,and the porosity and water absorption rise;(3)The optimum content of baking-free slag-sludge bricks is aluminum industrial slag 30%and sludge 10%.After 7 days of curing,baking-free bricks boast higher performance,and fully meet the performance requirements of solid concrete bricks(MU40),which can reduce time costs,and enhance enterprise revenue.展开更多
Unilateral sulfate attack of cementitious materials containing 40% slag with different water to binder ratios was investigated. The results showed that the degradation of slag blended cement pastes was nearly from the...Unilateral sulfate attack of cementitious materials containing 40% slag with different water to binder ratios was investigated. The results showed that the degradation of slag blended cement pastes was nearly from the corners of paste surface with cracking and spallings, water-to-binder（w/b） ratio made a significant sense to the damage that low w/b ratio led to little weight loss, less cracking and spalling damage and vice versa. Microstructural experimental results demonstrated that in the three different stages of sulfate attack, degradation of pastes was primarily associated with the migration behavior and bonding configuration of aluminum, in the early ages Al was mostly present in C-（A）-S-H, and thus, the damage of pastes hardly appeared while at later ones Al had been largely transferred from C-（A）-S-H into AFt, leading to expansive damage.展开更多
Aluminum recycling is an important activity that allows returning this metal to the market saving energy and resources. This activity generates slag and dross, both hazardous materials, which are recovered by other in...Aluminum recycling is an important activity that allows returning this metal to the market saving energy and resources. This activity generates slag and dross, both hazardous materials, which are recovered by other industries (tertiary sector). In that process, new wastes are produced, but most of them are disposed in security storage facilities because of their hazardousness and scarce marketable value. In Spain, the statistical data analysis on waste reveals that this sector is increasing every year. This study aims to characterize the wastes generated by the tertiary aluminum industries in Spain. Samples were collected in different aluminum recycling industries and characterized by chemical analyses, X-ray fluorescence, X-ray diffraction and particle size determination. Wastes rich in aluminum oxide and alkaline elements also comprise metallic aluminum and aluminum nitride. Such components are the main responsible for the waste hazardousness since they generate toxic gases in the presence of water. Besides, their fine granulometry (x50 < 30 μm) also contributes highly to the hazardousness.展开更多
Composites are most promising materials of recent interest. Metal matrix composites (MMCs) possess significantly improved properties compared to unreinforced alloys. There has been an increasing interest in composites...Composites are most promising materials of recent interest. Metal matrix composites (MMCs) possess significantly improved properties compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. In view of the generation of large quantities of solid waste by products like fly ash and slags, the present expensive manner in which it is discarded, new methods for treating and using these solid wastes are required. Hence, composites with fly ash and granulated blast furnace (GBF) slag as reinforcements are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications. In the present investigation, AA 2024 alloy-5 wt% fly ash and GBF slag composites separately were made by stir casting route. Phase identification and structural characterization were carried out on fly ash and GBF slag by X-ray diffraction studies. Scanning electron microscopy with energy dispersive X-ray spectroscopy EDS was used for microstructure analysis. The hardness and compression tests were carried out on all these alloy and composites. The SEM studies reveal that there was a uniform distribution of fly ash and GBF slag particles in the matrix phase and also very good bonding existed between the matrix and reinforcement. Improved hardness and mechanical properties were observed for both the composites compared to alloy;this increase is higher for Al-fly ash composite than Al-GBF slag composite.展开更多
基金The project was supported by the Natural Science Foundation of Fujian Province (No T08J0129)the Science and Technology Developing Foundation of Fuzhou University (No 2008-XQ-001)2007-year New Century Talents Supporting Program of Fujian Province (No XSJRC2007-17)
文摘Aluminum titanate was in-situ synthesized by using industrial waste-residue in the aluminum factory and TiO2 as the main raw materials and the influence of different reaction temperatures on the purity and microstructures of synthesized products were mainly discussed. The obtained Al2TiO5 was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and relevant analytical software. The results show that elevating the sintering temperature can increase the content of aluminum titanate; and at 1420 ℃, it reaches the highest in the synthesized ceramic. When the sintering temperature continues to increase, the produced aluminum titanate will decompose resulting in the drop of its content. Therefore, the optimum sintering temperature of in-situ synthesis of aluminum titanate is determined as 1420 ℃, at which the grains of aluminum titanate grow completely, the purity of aluminum titanate is 89.3wt%., the highest density is 2.75 g/cm^3, and the porosity is 9%.
基金This project was supported by the 863 Project (2003AA322020)
文摘By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.
基金This work was supported by the '863' Project (2003AA322020)
文摘The influence of Fe2O3 impurity on the crystalline structure of cordierite synthesized from waste aluminum slag is discussed. XRD and SEM techniques were employed to characterize the crystalline structure and microstructure of each specimen. Philips X’pert plus software was used to determine the lattice parameters of each specimen. The results show that the Fe2O3 content of 0.8～1.6wt% is beneficial to the formation of cordierite, with the cordierite amount reaching 90wt%. So 0.8～1.6wt% is considered as the allowable Fe2O3 content in the specimens and 0.8wt% is determined to be the best after overall analysis. Plus software analysis shows that the cordierite in each specimen has the same symmetrical hexagonal structure as the single crystal, and the lattice parameters as well as the lattice dimensions change slightly.
基金Supported by the National Natural Science Foundation of China(Nos.51102047 and 51472050)
文摘Waste aluminum slag and oyster shell were used as raw materials to synthesize calcium hexaluminate（CA6）. The effects of different source materials of CaO and sintering temperature on the structures and properties of CA6 were investigated,respectively. The results show that compared to calcium oxide,oyster shell can lower the formation temperature of CA6,hence CA6 can be detected at 1300 ℃ by using oyster shell as the starting raw materials. Increasing the sintering temperature can promote the crystal growth. CA6 crystals show typical platelet shape,and its optimum sintering temperature falls in the 1450～1550 ℃ region. The bulk density is 1.54～1.83 g/cm^3,the apparent porosity is 44.1～55.2% and the flexural strength is 10.8～25.3 MPa.
基金This work was supported by the "863" project (2003AA322020)
文摘By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.
基金Science and Technology Project of Henan Water Resources Department support program.No.GG202040Fund of Innovative Education Program for Graduate Students at North China University of Water Resources and Electric Power,China.No.YK2020-04.
文摘In order to explore the relationship between the macroscopic properties and pore structure characteristics of baking-free slag-sludge bricks,the compressive strength and water absorption rate using aluminum industrial slag and sludge of different substitution rates were tested.Optical instruments and image analysis software were used to measure the parameters of the pore structure.Specifically,a fractal model was built based on the fractal theory,in which the fractal dimension was used as the characteristic index of the pore structure to analyze the correlation and interaction mechanism between the fractal dimension and the macroscopic mechanical properties.Based on this study,conclusions were drawn as follows:(1)The plane pore structure of baking-free bricks shows good fractal characteristics.With the increase of the aluminum industrial slag content,the fractal dimension becomes smaller and the pore structure develops well;with the increase of the sludge content,the fractal dimension becomes larger and the pore structure becomes worse;(2)As the fractal dimension of the plane pore structure increases,the compressive strength of baking-free bricks falls,and the porosity and water absorption rise;(3)The optimum content of baking-free slag-sludge bricks is aluminum industrial slag 30%and sludge 10%.After 7 days of curing,baking-free bricks boast higher performance,and fully meet the performance requirements of solid concrete bricks(MU40),which can reduce time costs,and enhance enterprise revenue.
基金Funded by the National Key Research Program(973 Program)(No.2015CB655101)National Natural Science Foundation of China(No.51379163)
文摘Unilateral sulfate attack of cementitious materials containing 40% slag with different water to binder ratios was investigated. The results showed that the degradation of slag blended cement pastes was nearly from the corners of paste surface with cracking and spallings, water-to-binder（w/b） ratio made a significant sense to the damage that low w/b ratio led to little weight loss, less cracking and spalling damage and vice versa. Microstructural experimental results demonstrated that in the three different stages of sulfate attack, degradation of pastes was primarily associated with the migration behavior and bonding configuration of aluminum, in the early ages Al was mostly present in C-（A）-S-H, and thus, the damage of pastes hardly appeared while at later ones Al had been largely transferred from C-（A）-S-H into AFt, leading to expansive damage.
文摘Aluminum recycling is an important activity that allows returning this metal to the market saving energy and resources. This activity generates slag and dross, both hazardous materials, which are recovered by other industries (tertiary sector). In that process, new wastes are produced, but most of them are disposed in security storage facilities because of their hazardousness and scarce marketable value. In Spain, the statistical data analysis on waste reveals that this sector is increasing every year. This study aims to characterize the wastes generated by the tertiary aluminum industries in Spain. Samples were collected in different aluminum recycling industries and characterized by chemical analyses, X-ray fluorescence, X-ray diffraction and particle size determination. Wastes rich in aluminum oxide and alkaline elements also comprise metallic aluminum and aluminum nitride. Such components are the main responsible for the waste hazardousness since they generate toxic gases in the presence of water. Besides, their fine granulometry (x50 < 30 μm) also contributes highly to the hazardousness.
文摘Composites are most promising materials of recent interest. Metal matrix composites (MMCs) possess significantly improved properties compared to unreinforced alloys. There has been an increasing interest in composites containing low density and low cost reinforcements. In view of the generation of large quantities of solid waste by products like fly ash and slags, the present expensive manner in which it is discarded, new methods for treating and using these solid wastes are required. Hence, composites with fly ash and granulated blast furnace (GBF) slag as reinforcements are likely to overcome the cost barrier for wide spread applications in automotive and small engine applications. In the present investigation, AA 2024 alloy-5 wt% fly ash and GBF slag composites separately were made by stir casting route. Phase identification and structural characterization were carried out on fly ash and GBF slag by X-ray diffraction studies. Scanning electron microscopy with energy dispersive X-ray spectroscopy EDS was used for microstructure analysis. The hardness and compression tests were carried out on all these alloy and composites. The SEM studies reveal that there was a uniform distribution of fly ash and GBF slag particles in the matrix phase and also very good bonding existed between the matrix and reinforcement. Improved hardness and mechanical properties were observed for both the composites compared to alloy;this increase is higher for Al-fly ash composite than Al-GBF slag composite.
