More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. Howeve...More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. However, most of fly ash is currently landfilled as waste due to lack of efficient purification technologies to separate unburned carbon from fly ash. A rotary triboelectrostatic separator has been developed and patented recently at the University of Kentucky with unique features. Several fly ash samples have been used to understand the effects of major process parameters on the separation performance. The results show that compared to existing triboelectrostatic separators, the rotary triboelectrostatic separator has significant advantages in particle charging efficiency, solids throughput, separation efficiency, applicable particle size range.展开更多
This study was performed to investigate the feasibility of applying a Rotary Triboelectrostatic Separator(RTS) to the beneficiation of Eshidiya phosphate minerals.RTS separation tests were carried out on phosphatic ...This study was performed to investigate the feasibility of applying a Rotary Triboelectrostatic Separator(RTS) to the beneficiation of Eshidiya phosphate minerals.RTS separation tests were carried out on phosphatic bed A_1,phosphatic bed A_3 and slime samples.The bed A_1 and slime samples were tested without desliming.Two sets of tests were performed using the A_3 sample: one was performed without desliming and the other with the A_3 sample deslimed.RTS separation tests as initially performed on the bed A_1 and slime samples gave products that had essentially the same P_2O_5 content.This indicated that adsorbed clay particles on the phosphate surface are responsible for the poor separation of un-deslimed phosphates.Better triboelectrostatic separation was observed with the undeslimed A_3 phosphate sample;these tests resulted in a highest product grade of 26%P_2O_5.The deslimed A_3 sample showed far more effective separation than the undeslimed A_3 one.In fact,a concentrate of 34%P_2O_5 was obtained from the triboelectrcstatic separation of deslimed A_3.The results indicate that with deslimed A_3 P_2O_5 recovery was about 65%for a concentrate of 28%P_2O_5 and about 45%for a concentrate of 30%P_2O_5.These results clearly show the importance of desliming for effective beneficiation of phosphate by the RTS.A more efficient separation can be expected from optimized operating conditions and circuit configuration.展开更多
Accurate solid concentration measurement plays a key role in the process industry. Measurements analyzed offline can be used to estimate process efficiencies, to identify problems in a flow, and to validate computatio...Accurate solid concentration measurement plays a key role in the process industry. Measurements analyzed offline can be used to estimate process efficiencies, to identify problems in a flow, and to validate computational models. Online measurements can be used for active control. Electrical capacitance tomography (ECT) is a unique measuring technique with great potential in multiphase flow measurement. Experimental studies are carried out on a solid concentration measurement in a cyclone separator dipleg, using ECT. In this experiment eight electrodes are selected for the ECT sensor that is placed on the straight tube of the dipleg. The fluctuating characteristics according to the screw feeder and the effect of the airflow rate from the top of the cyclone are analyzed. The feasibility andreliability of the method are verified by the experimental results.展开更多
A simple, sensitive, and rapid analytical method is reported for the determination of surfactants. This is based on the use of an oppositely charged dye as the ion pair to form an ionic associate with the surfactant i...A simple, sensitive, and rapid analytical method is reported for the determination of surfactants. This is based on the use of an oppositely charged dye as the ion pair to form an ionic associate with the surfactant in a vessel, thus affording ion-associated adhesion on the inner wall of the vessel. After the adhesion, the remaining solution in the vessel is removed, and the ionic associate is dissolved in a suitable solvent. The absorbance of the resulting solution is measured spectrophotometrically to determine the concentration of the surfactant. Further, the mechanism of adhesion is elucidated.展开更多
The microstructure and properties of the coke samples collected from 4 different wall regions of the cyclone in the reactor of a residue fluid catalytic cracking unit(RFCCU) were analyzed by using the scanning-electro...The microstructure and properties of the coke samples collected from 4 different wall regions of the cyclone in the reactor of a residue fluid catalytic cracking unit(RFCCU) were analyzed by using the scanning-electron microscope(SEM), and the possible coke formation processes were investigated as well. The results showed that some of the heavy nonvolatile oil droplets entrained in the flowing oil and gas mixture could possibly deposit or collide on the walls by gravity settling or turbulence diffusion, and then were gradually carbonized into solid coke by condensing and polymerization along with dehydrogenation. Meanwhile some of fine catalyst particles also built up and integrated into the solid coke. The coke can be classified into two types, namely, the hard coke and the soft coke, according to its property, composition and microstructure. The soft coke is formed in the oil and gas mixture's stagnant region where the oil droplets and catalyst particles are freely settled on the wall. The soft coke appears to be loose and contains lots of large catalyst particles. However, the hard coke is formed in the oil and gas mixture's flowing region where the oil droplets and catalyst particles diffuse towards the wall. This kind of coke is nonporous and very hard, which contains a few fine catalyst particles. Therefore, it is clear that the oil and gas mixture not only carries the oil droplets and catalyst particles, but also has the effects on their deposition on the wall, which can influence the composition and characteristics of deposited coke.展开更多
The paper analyzes John Presper Eckert and John William Mauchly's endeavours to design, sell, and build the revolutionary new technology of the first-large and commercial computers. It discusses how Eckert and Mauchl...The paper analyzes John Presper Eckert and John William Mauchly's endeavours to design, sell, and build the revolutionary new technology of the first-large and commercial computers. It discusses how Eckert and Mauchly's conceptualization of the computer grew out of their Electronic Numerical Integrator and Calculator (ENIAC) and Electronic Discrete Variable Automatic Computer (EDVAC) projects at University of Pennsylvania. They incorporated their own business to gain profit from production and attain the freedom needed to develop their revolutionary new computer technology through a series of small and separate computer projects with private and government customers. The paper approaches innovation as a chaotic process and uses uncertainty to conceptualize the basic relations between actors and organizations.展开更多
文摘More than 80 million metric tons of fly ash is produced annually in the U.S. as coal combustion by-product. Coal fly ash can be converted to value-added products if unburned carbon is reduced to less than 2.5%. However, most of fly ash is currently landfilled as waste due to lack of efficient purification technologies to separate unburned carbon from fly ash. A rotary triboelectrostatic separator has been developed and patented recently at the University of Kentucky with unique features. Several fly ash samples have been used to understand the effects of major process parameters on the separation performance. The results show that compared to existing triboelectrostatic separators, the rotary triboelectrostatic separator has significant advantages in particle charging efficiency, solids throughput, separation efficiency, applicable particle size range.
基金the staff of the Jordan Phosphate Mines Company for supplying the sample used in the present work.
文摘This study was performed to investigate the feasibility of applying a Rotary Triboelectrostatic Separator(RTS) to the beneficiation of Eshidiya phosphate minerals.RTS separation tests were carried out on phosphatic bed A_1,phosphatic bed A_3 and slime samples.The bed A_1 and slime samples were tested without desliming.Two sets of tests were performed using the A_3 sample: one was performed without desliming and the other with the A_3 sample deslimed.RTS separation tests as initially performed on the bed A_1 and slime samples gave products that had essentially the same P_2O_5 content.This indicated that adsorbed clay particles on the phosphate surface are responsible for the poor separation of un-deslimed phosphates.Better triboelectrostatic separation was observed with the undeslimed A_3 phosphate sample;these tests resulted in a highest product grade of 26%P_2O_5.The deslimed A_3 sample showed far more effective separation than the undeslimed A_3 one.In fact,a concentrate of 34%P_2O_5 was obtained from the triboelectrcstatic separation of deslimed A_3.The results indicate that with deslimed A_3 P_2O_5 recovery was about 65%for a concentrate of 28%P_2O_5 and about 45%for a concentrate of 30%P_2O_5.These results clearly show the importance of desliming for effective beneficiation of phosphate by the RTS.A more efficient separation can be expected from optimized operating conditions and circuit configuration.
基金Supported by the National Natural Science Foundation of China (60672151, 60532020).
文摘Accurate solid concentration measurement plays a key role in the process industry. Measurements analyzed offline can be used to estimate process efficiencies, to identify problems in a flow, and to validate computational models. Online measurements can be used for active control. Electrical capacitance tomography (ECT) is a unique measuring technique with great potential in multiphase flow measurement. Experimental studies are carried out on a solid concentration measurement in a cyclone separator dipleg, using ECT. In this experiment eight electrodes are selected for the ECT sensor that is placed on the straight tube of the dipleg. The fluctuating characteristics according to the screw feeder and the effect of the airflow rate from the top of the cyclone are analyzed. The feasibility andreliability of the method are verified by the experimental results.
文摘A simple, sensitive, and rapid analytical method is reported for the determination of surfactants. This is based on the use of an oppositely charged dye as the ion pair to form an ionic associate with the surfactant in a vessel, thus affording ion-associated adhesion on the inner wall of the vessel. After the adhesion, the remaining solution in the vessel is removed, and the ionic associate is dissolved in a suitable solvent. The absorbance of the resulting solution is measured spectrophotometrically to determine the concentration of the surfactant. Further, the mechanism of adhesion is elucidated.
基金financial support from the National Natural Science Foundation of China (No. 21176250, No. 21566038)
文摘The microstructure and properties of the coke samples collected from 4 different wall regions of the cyclone in the reactor of a residue fluid catalytic cracking unit(RFCCU) were analyzed by using the scanning-electron microscope(SEM), and the possible coke formation processes were investigated as well. The results showed that some of the heavy nonvolatile oil droplets entrained in the flowing oil and gas mixture could possibly deposit or collide on the walls by gravity settling or turbulence diffusion, and then were gradually carbonized into solid coke by condensing and polymerization along with dehydrogenation. Meanwhile some of fine catalyst particles also built up and integrated into the solid coke. The coke can be classified into two types, namely, the hard coke and the soft coke, according to its property, composition and microstructure. The soft coke is formed in the oil and gas mixture's stagnant region where the oil droplets and catalyst particles are freely settled on the wall. The soft coke appears to be loose and contains lots of large catalyst particles. However, the hard coke is formed in the oil and gas mixture's flowing region where the oil droplets and catalyst particles diffuse towards the wall. This kind of coke is nonporous and very hard, which contains a few fine catalyst particles. Therefore, it is clear that the oil and gas mixture not only carries the oil droplets and catalyst particles, but also has the effects on their deposition on the wall, which can influence the composition and characteristics of deposited coke.
文摘The paper analyzes John Presper Eckert and John William Mauchly's endeavours to design, sell, and build the revolutionary new technology of the first-large and commercial computers. It discusses how Eckert and Mauchly's conceptualization of the computer grew out of their Electronic Numerical Integrator and Calculator (ENIAC) and Electronic Discrete Variable Automatic Computer (EDVAC) projects at University of Pennsylvania. They incorporated their own business to gain profit from production and attain the freedom needed to develop their revolutionary new computer technology through a series of small and separate computer projects with private and government customers. The paper approaches innovation as a chaotic process and uses uncertainty to conceptualize the basic relations between actors and organizations.