SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Beibei Liu,Baoyu Gao,Kangying Guo,Jingwen Pan,Qinyan Yue
Safe and effective coagulants are necessary for surface water treatment. The polyaluminum-titanium chloride (PATC) composite coagulant has promise but its application is limited due to the lack of fundamental theoretical research. We prepared a series of novel PATCs and investigated the effects of the interaction between Al (III) and Ti (IV) on the chemical species distribution, physicochemical properties and coagulation efficiencies. The Al-O-Ti bonds observed in the PATC infrared spectra were predicted by density functional theory computation to appear in 4-atom rings in the structure. The differences in Al species distribution of PATC and PAC illustrated that the introduction of Ti retarded the hydrolysis of monomeric Al species (Al a ) and medium polymerized Al species (Al b ) to colloidal Al species (Al c ) at low B levels, but the transformation was promoted at high basicities (B). PATCs exhibited higher charge densities and larger molecular weights than PAC at the same B levels, which contributed to their excellent coagulation efficiencies. PATC with low B values but high Al/Ti molar ratios mainly provided charge neutralization in removal of humic acid kaolin, while the dominant coagulation mechanism converted from charge neutralization to sweeping and bridging effects at high B values or low Al/Ti molar ratios.
研究领域:
环境科学
·
化学工程
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产品关联
DOI
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2023
·
IF 2.8
Guohua Li,Aimin Zhang,Xianjin Qi,Guizhi Yan,Gang Zhi
In the process of removing arsenic in an arsenic-containing aqueous solution, a large amount of harmful arsenic-containing waste is usually discharged. In this paper, a recyclable and environmentally friendly method of removing arsenic with Al/Ti-supported chitosan (ATC) was proposed. The results show that ATC has the best adsorption effect on arsenic at pH 8 at room temperature. In addition, the ratio of Al and Ti to chitosan (CB) affects the adsorption effect of ATC on arsenic. When Al: Ti: CB is 1:1:10, the removal rate of arsenic is as high as 99%. ATC can rapidly adsorb arsenic within 30 min. The adsorption kinetics shows that the adsorption of ATC on arsenic follows the joint action of physical adsorption and chemical precipitation. The adsorption isotherm shows that the adsorption process is multilayer adsorption. Finally, ATC has good recycling ability and is an efficient arsenic-removing agent in the treatment of arsenic-containing aqueous solutions. It shows great potential in the remediation of heavy metal-containing aqueous solutions.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Mengting Jiang,Xiaopeng Li,Tengfei Deng
In this study, aluminum titanate/anorthite (Al 2 TiO 5 -CaAl 2 Si 2 O 8 ) ceramics were fabricated from ferrotitanium slag through phase reconstruction. Stabilization of the ceramic was achieved by migration of Mg element into Al 2 TiO 5 phase. The results indicated that optimal performance was achieved with the addition of 4 wt% MgO and 60 wt% ferrotitanium slag at 1370°C. The ceramic exhibited bulk density of 3.11 ± 0.01 g/cm 3 , thermal storage density of 1.51 kJ/cm 3 , and thermal expansion coefficient of 3.40 × 10 −6 /°C (1000°C), respectively. Additionally, the solid solution of Mg 2+ in the Al 2 TiO 5 lattice reduced the formation of microcracks and enhanced the mass transfer process. Consequently, the sintering temperature decreased from 1415°C to 1370°C while the bending strength increased from 61.25 ± 1.05 MPa to 75.92 ± 7.72 MPa. Furthermore, finite element simulation demonstrated that higher thermal expansion led to concentrated thermal stress, potentially increasing the possibility of ceramic cracking. This research provides a new strategy for preparing low thermal expansion ceramics from titanium-containing solid waste.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2023
·Vol. 25
·期 19
·2300256
·
IF 3.6
Qian Ma,Anze Shui,Qingliang Shan,Changrong Chen,Chao He
ZrO 2 -modified aluminum titanate (Al 2 TiO 5 , AT) flexible ceramics are prepared by solid-state reaction method. The influence of sintering temperature and holding time on the microstructure and mechanical properties is investigated. Temperature-dependence behavior of the flexibility is observed. It is believed that temperature-dependence behavior of AT grain aspect ratio should take responsibility. However, average value of the aspect ratio remains unchanged regardless of holding time. Reasons are as follows: the formed zirconium titanate (ZrTiO 4 , ZT) grains could pin in AT grain boundaries, and internal stress generates between AT/ZT boundaries during grain growth process, thus inhibiting AT grain growth and reducing its growth rate, leading to AT grain refinement and increase of its aspect ratio. But, the increase of holding time reduces the inhibition effect and the increase of temperature strengthens the effect, resulting in rapid AT grain growth, especially its width. As a result, though the length and width of AT grains increase with the increase of holding time, its aspect ratio remains unchanged. On these bases, AT grain growth model related to holding time is proposed. It is expectable that the discovery of this study can deepen the research of particle pinning and provide a reference for abnormal grain growth.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Nan Zhang,Yang Yang,Lijing Fan,Xiaoxu Zheng,Jinglin Wang,Cancan Jiang,Shengjun Xu,Hui Xu,Dongsheng Wang
Excessive discharge of fluoride can lead to environmental pollution and human hazards. Coagulation is a widely used process for the removal of fluoride. Existing research on the interaction between coagulants and fluoride has primarily concentrated on the removal of fluoride and the selection of coagulants, while studies on floc aging are lacking. Understanding the aging process of flocs can provide valuable insights into the mechanisms of interaction between coagulants and fluoride and further provide guidance for coagulation as well as sludge return processes. This study compares the fluoride removal efficiencies of two coagulants: polyaluminum-titanium chloride (PATC) and polyaluminum chloride (PACl), and examines the change patterns of fluoride ion during aging (0–120 h). Additionally, the study characterizes the impact of Ti or Al-Ti on the aging process using FTIR, XPS, XRD, and ESI-TOF-MS analyses. The results of the study demonstrate that the fluoride removal efficiency of PATC is 20.2% higher than that of PACl at a dosage of 0.8 mmol/L. The introduction of titanium provides additional binding sites for F − , resulting in a more intricate floc structure. Moreover, titanium promotes the hydrolytic polymerization of aluminum, increasing its positive charge and making it more attractive to F − . Upon the complete precipitation of the flocs, F − in the supernatant of PATC (0–6 h) and PACl (6–72 h) competes with -OH for binding sites, while F − attacks the Al-O or Al-O-Ti bond, leading to the disruption of the polymer. As time progresses, PATC flocs (6–120 h) are less affected by aging than PACl flocs (72–120 h). Throughout the aging process, PATC releases less F − at a slower rate, presumably because the introduction of titanium inhibited the dehydration and crystallization of the flocs to delay the release of F − .
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qian Ma,Anze Shui,Hulei Yu
The thermal shock behaviors of the multiple crack system based on aluminum titanate (Al 2 TiO 5 , AT) flexible ceramics are investigated. Two (fine/coarse-grained) systems are employed in this study to observe the influence of the grain size and microcrack size on the thermal shock behaviors of AT flexible ceramics. The findings reveal that these two systems exhibit markedly different adversarial strategies against high-temperature thermal shock. The coarse-grained system disperses the thermal stress by introducing new cracks and making stress evenly dispersed, while the fine-grained one can only concentrate thermal stress on limited microcracks. This is because almost all the grain boundaries in the coarse-grained system could serve as crack source sites, while that was only approximately 1/3 in the fine-grained one. Consequently, as the thermal shock temperature increases, the strain of the coarse-grained system first increases and then decreases, while its strength shows double peaks and double valleys. As for the fine-grained one, the strain decreases with the temperature increase, while its strength first increases and then decreases. Therefore, it can be concluded that the mechanical properties of AT flexible ceramics are closely related to microcracks' size and stress state. And, the conclusion that there exists a favorable state of internal stress and a favorable influence of microcracks that is beneficial to the mechanical performance of AT flexible ceramics could be drawn.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
RARE METALS
·
2020
·Vol. 40
·期 7
·1940-1948
·
IF 2.161
Li Jia-Xin,Chen Yu-Hong,Bai Zhang-Jun,Zhao Bao-Jun,Jiang Liang,Wu Lan-Er
Ta–W alloys have unique properties but their applications at high temperatures are restricted due to their poor oxidation resistances. The addition of Al and Ti decreases the oxidation rate of the alloy, as Al-contained protective oxide layer could be formed. In this study, ternary and quaternary Ta–W alloys containing Al and Ti were prepared by hot press sintering. The microstructures and oxidation behaviors of the alloys were studied at 1173 K. The results show that the oxidation kinetics of all alloys follows a parabolic law at short oxidation periods. After cyclic oxidation, the kinetics of quaternary alloys still obeys the parabolic law but that of ternary alloy has been changed into linear law kinetics after 8-h oxidation. For ternary alloy, an outer layer with dense and continuous alumina was formed during the initial stage, and phase transformation caused the oxides to peel off. By comparison, the quaternary alloys depicted continuously solid solution of the oxides layer. Overall, Al and Ti played key roles in oxidation degree and affected the oxidation kinetics of ternary and quaternary alloys.
研究领域:
材料科学
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金属学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Junhua Chen,Guo Feng,Feng Jiang,Li Yin,Qianqian Zhao,Shanfang Lan,XiaoJun Zhang,Jianmin Liu,Qing Hu,Weihui Jiang
Novel Ni-doped Al 2 TiO 5 emerald green ceramic pigments were successfully synthesized for the first time. Several characterization techniques (XRD, XPS , SEM, TEM, UV–Vis, and automatic colorimeters) were used to determine the phase composition and stability of the pigments, as well as the valence state of the doped nickel ion . The results show that nickel ion replaces the Al 3+ in the aluminum titanate lattice in the form of Ni 2+ , which reduces the distortion of the octahedral structure. Ni-doping of the aluminum titanate lattice produces an excellent coloring effect and significantly promotes the synthesis and stabilization of aluminum titanate. The novel pigments have excellent color stability while maintaining exceptional coloring performance and thermal stability in a base glaze synthesized at 1200 °C. These pigments show considerable potential for high-temperature applications.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yawen Cai,Yapeng Ma,Jinghua Feng,Mingyu Zhu,Xin Wang,Zhimin Lv,Ming Fang,Xiaoli Tan,Xiangke Wang
The efficient treatment of uranium (U) is an important and challenging issue regarding radioactive wastes management. Adsorbent with high efficacy, low-cost is urgently needed for alleviating the contamination of U-containing wastewaters. To solve these issues, we report a series of phytic acid (PA) modified Zn-Al-Ti layered mixed metal oxides (Zn-Al-Ti LMO@PAs) in this work, which shows the adsorption capacity as high as ∼1486 mg/g and could be easily obtained through a facile post-modification method. The adsorption performance of Zn-Al-Ti LMO@PAs for U(VI) are carefully estimated through batch experiments. With the aid of batch experiments and various characterization techniques, PA in Zn-Al-Ti LMO@PAs is found to make the most contribution for the chelation of U(VI), which favors for the adsorption selectivity and capability. The Zn-Al-Ti LMO@PAs are potential cost-effective adsorbents to remove the U(VI) in wastewaters.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Mengting Jiang,Chenying Shi,Yuling Liu,Xiaopeng Li,Tengfei Deng
The mechanism of Mg 2+ introduction on the thermal expansion properties of Al 2 TiO 5 ceramics was elucidated through experimental characterization and theoretical calculation for Mg x Al 2(1-x) Ti 1+x O 5 (x = 0, 0.25, 0.50, 0.75). Results showed that as x increased from 0 to 0.75, the calculated thermal expansion coefficient (single-crystal) exhibited minimal variation, while the apparent thermal expansion coefficient (polycrystalline) increased from 0.09 × 10 -6 K -1 to 3.85 × 10 -6 K -1 (1000 °C). The low apparent thermal expansion of Al 2 TiO 5 (x = 0) was attributed to microcrack healing and pore compensation effects. For x = 0.75, the enhanced apparent thermal expansion was correlated with reduced microcrack formation and improved densification. The incorporation of Mg 2+ reduced octahedral distortion and lattice stiffness, thereby suppressing transverse vibrations of bridging oxygen atoms and contraction along the c-axis. This reduced thermal expansion anisotropy and minimized microcrack formation. Additionally, as Mg 2+ content increased from x = 0 to x = 0.75, the porosity reduced from (11.23 ± 0.13) % to (3.96 ± 0.24) %, thereby weakening the pore compensation effect. These findings provide valuable insights for designing Al 2 TiO 5 -based ceramics with low thermal expansion.
研究领域:
材料科学
·
无机非金属材料
·
热物理性能
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Shuai Tang,Xianwei Hu,Jiangyu Yu,Aimin Liu,Zhongning Shi,Zhuo Li,Yifan Zhang,Zhaowen Wang
The NaF-AlF 3 -TiO 2 ternary system is often used in the molten salt electrolysis process to produce Al-Ti alloys. In order to explore the dissolution reaction of TiO 2 in NaF-AlF 3 melts, the ionic structure of (6.58NaF-AlF 3 )-TiO 2 molten salts was examined by Raman spectroscopy combined with computational simulation in the present study. The results indicated that when TiO 2 was added to 6.58NaF-AlF 3 molten salt, it first reacted with F - or AlF 6 3- with the following reactions: 2F - +2TiO 2 = Ti 2 O 4 F 2 2- , 4AlF 6 3- +6TiO 2 = 2Al 2 O 3 + 3Ti 2 O 2 F 6 2- +6F - , and then the generated Al 2 O 3 reacted with TiO 2 and F - or AlF 6 3- with the following reactions: Al 2 O 3 + 3TiO 2 + 21F - =3TiO 3 F 3 5- +2AlF 6 3- , Al 2 O 3 + 4AlF 6 3- =3Al 2 OF 8 4- , Al 2 O 3 + 4AlF 6 3- =3Al 2 OF 6 2- +6F - . In addition, Ti 2 O 2 F 6 2- , TiO 3 F 3 5- and Ti 2 O 4 F 2 2- clusters belonged to Cs, C2v and C1 point group, and the main characteristic Raman bands of these clusters were due to the stretching vibration of O 1 -Ti 3 -O 2 -Ti 4 , Ti 1 -O 7 and O 6 -Ti 2 -O 5 and/or O 7 -Ti 1 -O 8 , respectively. What’ more, the main characteristic Raman bands of Ti 2 O 2 F 6 2- , TiO 3 F 3 5- and Ti 2 O 4 F 2 2- were located at 790, 850 and 900 cm −1 , respectively.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2016
·Vol. 70
·期 12
·1632-1641
·
IF 1.326
Hui-Hong Lü,Min-Zhi Wu,Zheng-Li Zhang,Xing-Rong Wu,Liao-Sha Li,Zhi-Fang Gao
The co-precipitation behaviour of a simulated Al 2 (SO 4 ) 3 –TiOSO 4 –Na 2 SiO 3 solution that imitated the lixivium of Ti-bearing blast furnace slag (Ti-slag) leached by sulphuric acid was investigated in this study. Various chemical analyses were employed to study the selective precipitation of multiple target components. Based on the high-added-value applications of Ti-slag, a new method was developed to prepare aluminium titanate composites from titanium-containing silicates. The findings demonstrate that the onsets of Ti and Al precipitation occur at pH values of 3.5 and 5.0, respectively, followed by Si precipitation. The particle sizes of the co-precipitates were greatly influenced by the precipitants, pH and the initial Al/Ti mole ratio. The results also show that the precipitation ratio of Ti, Al and Si generally increases with the pH and temperature, regardless of the Al/Ti mole ratio. The Si-O-Al, Ti-O-Al, and Ti-O-Si bonds that were formed were dependent on the pH and the initial Al/Ti mole ratio. There was a synthesis path for β -Al 2 TiO 5 (AT) from the solid-state reaction between rutile and α -Al 2 O 3 at 1362.5°C. The AT composites were successfully prepared by sintering the co-precipitates at 1450°C, which exhibited good thermal stability as estimated by the XRD measurements of the sample annealed at 1200°C for 4 hours.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）