Aluminum foams were fabricated by melt-based route using ZrH2 as a foaming agent. The factors which affected the foaming of aluminum foams during casting process were investigated. The powdered zirconium hydride with ...Aluminum foams were fabricated by melt-based route using ZrH2 as a foaming agent. The factors which affected the foaming of aluminum foams during casting process were investigated. The powdered zirconium hydride with content of 0.6%-1.4% （mass fraction） was added to the molten pure aluminum and the foaming condition was controlled in a temperature range from 933 to 1 013 K, Ca amount of 1.5%-3.0% （mass fraction）, stirring time of 0.5-2.5 min and holding time of 1.5-4.0 min to obtain homogeneous aluminum foams. The fabricated aluminum foams were characterized by XRD, SEM and Image-pro plus. The mechanical properties of the aluminum foams with different relative density were tested. The result indicates that the foaming agent （ZrH2） is suitable for the preparation of small aperture aluminum foams with average pore diameter of 1 mm. Inter-metallic compounds and Al2O3 have effect on the melt viscosity. The aluminum foams experience linear elastic, platforms and densification process and had a higher efficiency of energy absorption.展开更多
One characteristic of electro-flotation is the presence of micro bubbles that are well known for improving the flotation performance of fine particles. An electro-flotation method was studied with fine scheelite and f...One characteristic of electro-flotation is the presence of micro bubbles that are well known for improving the flotation performance of fine particles. An electro-flotation method was studied with fine scheelite and fluorite particles sized into three different fractions. Experiments were performed in a modified Hallimond tube. We investigated the effects of gas holdup, particle size, and different mesh electrode apertures on mineral recovery. Flotation results show that two size fractions show increased flotation recovery as the gas holdup increases. For the sized scheelite and fluorite, the flotation effect is diverse for different sizes of the cathode aperture. Pictures of the bubbles taken by a high speed CCD were used to determine the hydrogen bubble size distribution generated as a function of collector, current density, and electrode size. The diameters of the hydrogen bubbles ranged from 12 to 117μm in alkaline conditions.展开更多
基金Project (2004AA33G060) supported by the National High-tech Research and Development Program of China
文摘Aluminum foams were fabricated by melt-based route using ZrH2 as a foaming agent. The factors which affected the foaming of aluminum foams during casting process were investigated. The powdered zirconium hydride with content of 0.6%-1.4% （mass fraction） was added to the molten pure aluminum and the foaming condition was controlled in a temperature range from 933 to 1 013 K, Ca amount of 1.5%-3.0% （mass fraction）, stirring time of 0.5-2.5 min and holding time of 1.5-4.0 min to obtain homogeneous aluminum foams. The fabricated aluminum foams were characterized by XRD, SEM and Image-pro plus. The mechanical properties of the aluminum foams with different relative density were tested. The result indicates that the foaming agent （ZrH2） is suitable for the preparation of small aperture aluminum foams with average pore diameter of 1 mm. Inter-metallic compounds and Al2O3 have effect on the melt viscosity. The aluminum foams experience linear elastic, platforms and densification process and had a higher efficiency of energy absorption.
基金National Natural Science Foundation of China (No. 51074184)
文摘One characteristic of electro-flotation is the presence of micro bubbles that are well known for improving the flotation performance of fine particles. An electro-flotation method was studied with fine scheelite and fluorite particles sized into three different fractions. Experiments were performed in a modified Hallimond tube. We investigated the effects of gas holdup, particle size, and different mesh electrode apertures on mineral recovery. Flotation results show that two size fractions show increased flotation recovery as the gas holdup increases. For the sized scheelite and fluorite, the flotation effect is diverse for different sizes of the cathode aperture. Pictures of the bubbles taken by a high speed CCD were used to determine the hydrogen bubble size distribution generated as a function of collector, current density, and electrode size. The diameters of the hydrogen bubbles ranged from 12 to 117μm in alkaline conditions.
