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Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrometallurgy of China is the property of Hydrometallurgy of China Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Secondary aluminum ash is a byproduct in the aluminum industry that contains valuable components, such as aluminum nitride (AlN) and aluminum oxide (Al2O3). AlN has excellent thermal and electrical properties and is widely used in various applications, making the recovery of AlN from secondary aluminum ash essential for both economic and environmental reasons. In this study, we developed a novel triboelectric separation technique to recover AlN from aluminum ash by investigating the tribocharging characteristics of the main components of secondary aluminum ash, Al2O3 and AlN. We studied the effects of tribocharging ball ratio, friction time, and stirring speed on the tribocharging of pure Al2O3 and AlN, using various materials such as polytef (PTFE), polypropylene (PP), polyvinyl chloride (PVC), copper (Cu), and stainless steel (SS) as tribocharging materials. We also examined the effects of friction medium ball ratio, friction medium material, rotational speed, and voltage on the triboelectric separation process. Our results showed that the charge-to-mass ratio for Al2O3 and AlN was 1.96 and −15.56 nC/g, respectively, the difference is largest, with a PTFE ball, a 1:5 ratio, a stirring speed of 290 n/min, and a tribocharging duration of 30 s. The triboelectric sequence of these friction materials was (+)PTFE, PP, Al2O3, SS, Cu, PVC, and AlN (-). To recover AlN from aluminum ash, PTFE should be chosen as the friction medium, and a friction medium ball ratio of 1:3, rpm rotation speed of 50, and voltage of 40kV should be used, resulting in an AlN grade of 89.25% and a significant increase in the recovery rate of AlN in the positive and negative electrode. Our findings demonstrate the feasibility of effective triboelectric separation of Al2O3 and AlN. [ABSTRACT FROM AUTHOR]

Secondary aluminum ash (SAA) is a type of common solid waste which leads to pollution without treatment. Due to its chemical reactivity, the application of SAA to reactive powder concrete (RPC) may help solidify this solid waste while increasing its performance. However, RPC is usually in active service when used with steel bars. NaCl can corrode the steel bars when reinforced RPC is used in a coastal environment. In this study, the corrosion resistance of reinforced RPC was investigated. The specimens were exposed to an environment of NaCl with freeze–thaw cycles (F-Cs) and dry–wet alternations (D-As). The corresponding mass loss rates (MRs), the electrochemical impedance spectroscopy (EIS) curves and the dynamic modulus of elasticity (DME) were measured. The results show that the MR and the DME of reinforced RPC decrease with increasing values of F-C and D-A. F-C and D-A increases lead to increased electrical resistance (R). The real part value corresponding to the extreme point of the EIS curve is increased by 0~213.7% when the SAA is added. The relationship between the imaginary part and the real part of the EIS fits the quadratic function. The equivalent circuit of the reinforced RPC is obtained from the EIS curves. The R of the rust is calculated by using the equivalent circuit. The rust's R decreases in the quadratic function with the mass ratio of the SAA. After 200 NaCl F-Cs, the MR, the DME and the R vary within the ranges of 23.4~113.6%, −2.93~−4.76% and 4.92~13.55%. When 20 NaCl D-As are finished, the MR, the DME and the R vary within the ranges of 34.7~202.8%, −13.21~−14.93% and 120.48~486.39%. The corrosion area rates are 2.3~68.7% and 28.7~125.6% higher after exposure to 200 NaCl F-Cs and 20 NaCl D-As. When the SAA is mixed, the MR is decreased by 0~13.12%, the DME increases by 0~3.11%, the R of the reinforced RPC increases by 26.01~152.43% and the corrosion area rates are decreased by 21.39~58.62%. This study will provide a novel method for solidifying SAA while improving the chlorine salt resistance of RPC. [ABSTRACT FROM AUTHOR]

Secondary aluminum ash is a kind of common solid waste which will pollute the environment without any treatment. In this study, the influence of secondary aluminum ash on the rheological properties and the initial setting time of fresh reactive powder concrete (RPC) are researched. Meanwhile, the mechanical properties and the drying shrinkage rates of RPC with the secondary aluminum ash are determined. The electrical parameters of RPC with the secondary aluminum ash are measured. Scanning electron microscopy is obtained to reflect the internal structure of RPC. Results show that the addition of secondary aluminum ash can lead to decreasing the fluidity and increase the yield shear stress of fresh RPC paste by varying rates of 16.1% and 58.3%, respectively. The addition of secondary aluminum ash can decrease the flexural and compressive strengths of RPC cured for 1 day by the decreasing rates of 0~18.7% and 0~19.3%. When the curing age is 28 days, the flexural and compressive strengths of RPC are increased by 0~9.1% and 0~19.1% with adding the secondary aluminum ash. The secondary aluminum ash can promote the condensation of RPC. The addition of the secondary aluminum ash can decrease the electrical resistance of RPC by an order of magnitude. The relationship between the electrical resistance and the electrical reactance fits the quadratic function equation. The electrical resistance of the pore solution increases in the form of a quadratic function with the mass ratio of the secondary aluminum ash. The dry shrinkage rates of RPC cured for 1 day and 28 days are decreased by 0~36.4% and 0~41.3% with the increasing dosages of secondary aluminum ash. As obtained from the microscopic testing results, the secondary aluminum ash can improve the compactness of hydration products. [ABSTRACT FROM AUTHOR]

Secondary aluminum ash (SAA) is a common waste that, without reasonable treatment, results in pollution to the environment. A large amount of CO2 is emitted by human activities every day. If the CO2 cannot be treated in a timely manner, it will accelerate the greenhouse effect and pollute the environment. The CO2 curing on the surface of SAA can reduce excess CO2 emissions while improving the performance of the SAA. The application of CO2-cured SAA can simultaneously consume the emitted CO2 and solidify the SAA. In this article, the effect of CO2-cured secondary aluminum ash on the rheological properties, the initial setting time, the flexural strength (ft), the compressive strength (fcu) of reactive powder concrete (RPC), and the corresponding dry shrinkage rate (DSR) are investigated. Meanwhile, the capillary water absorption, the chloride ion migration coefficient (CMC), and the carbonization depth of RPC are determined. Scanning electron microscope (SEM) and the X-ray diffraction spectrum curves are selected to reveal the mechanism of the macro performance. Results indicate that CO2-cured secondary aluminum ash can increase the fluidity and decrease the plastic viscosity of fresh RPC. The initial setting time is increased by the CO2 curing. CO2-cured secondary aluminum ash can increase the ft and fcu by (0%~26.3% and 0% to 68.7%), respectively. The DSR is increased by adding secondary aluminum ash with an increasing rate of 0% to 91.3%. The capillary water absorption of RPC increases in the form of a linear function. The CMC and the carbonization depth of RPC are decreased by adding the CO2-cured secondary aluminum ash with decreasing rates of 0%~46.7% and 0%~45.7%. The CO2-cured secondary aluminum ash can make the hydration more compact and increased increase the hydration products (Ca(OH)2). [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals Engineering is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)