Microstructure and texture evolution in LZ91 magnesium alloy during cold rolling

LZ91 magnesium alloy extruded sheets were subjected to cold rolling.The microstructure and texture evolution were tracked using optical microscopy(OM)and X-ray diffraction(XRD).Theα-Mg andβ-Li phases were elongated along rolling direction(RD),contributing to the formation of a thin lamellar“sandwich”structure.This“sandwich”structure is favored for glissile dislocation ofα-Mg phase during rolling.Theα-Mg andβ-Li phases are near Burgers orientation relationship,resulting in an unusual RD texture component in(0002)pole figure.

Microstructure and electrolysis behavior of self-healing Cu-Ni-Fe composite inert anodes for aluminum electrowinning

The microstructure evolution and electrolysis behavior of(Cu_(52)Ni_(30)Fe_(18))–x Ni Fe_2O_4(x=40wt%,50wt%,60wt%,and 70wt%)composite inert anodes for aluminum electrowinning were studied.Ni Fe_2O_4 was synthesized by solid-state reaction at 950°C.The dense anode blocks were prepared by ball-milling followed by sintering under a N_2 atmosphere.The phase evolution of the anodes after sintering was determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy.The results indicate that a substitution reaction between Fe in the alloy phase and Ni in the oxide phase occurs during the sintering process.The samples were also examined as inert anodes for aluminum electrowinning in the low-temperature KF–NaF–AlF_3 molten electrolyte for 24 h.The cell voltage during electrolysis and the corrosion scale on the anodes were analyzed.The results confirm that the scale has a self-repairing function because of the synergistic reaction between the alloy phase with Fe added and the oxide phase.The estimated wear rate of the(Cu_(52)Ni_(30)Fe_(18))–50Ni Fe_2O_4 composite anode is 2.02 cm·a^(-1).

惰性阳极铝电解槽内的气泡行为（英文）

气泡的行为是惰性阳极铝电解槽设计和工艺控制必须考虑的重要因素。为了研究气泡的行为和电解质的流动形态,构建了透明铝电解槽以进行观察。试验结果表明:受阳极气体的驱动,槽内电解质围绕阴极作循环运动,并在局部区域形成旋涡。气体产生于阳极底掌和垂直工作面。在阳极底掌,能够观察到气泡的形成、长大、滑移和脱离等现象。然而,阳极垂直工作面产生的气体则迅速脱离,然后向上运动,途中与别的气泡碰撞,导致气泡的并聚或破碎。大部分气泡达到液面时立即逸出至空气中,少部分气泡被冲出水平液面的电解质携带着继续向上运动,形成一个波峰,然后作水平运动并最终逸出。在电解质表面,部分气泡能保持不破裂,并在电解质上滑动。通过对比分析,惰性阳极上产生的气泡比石墨阳极上产生气泡的直径小。另外,石墨阳极上的气泡不呈球形,而呈圆盘状或扁平状,惰性阳极上的气泡则近似呈球状。

Synthesis and characterization of a novel collector for the desulfurization of fine high-sulfur bauxite via reverse flotation

Bauxite is one of the main raw materials in the alumina industry.Fine high-sulfur bauxite flotation desulfurization is a great challenge presently.This study aims to synthesize nanoparticle collectors(NPCs)by emulsion polymerization to improve the abovesaid flotation desulfurization process.The physicochemical properties of high-sulfur bauxite were analyzed,and the experimental conditions for the synthesis of NPCs were optimized.The interaction mechanism between NPCs and pyrite was studied via fundamental analyses including SEM(Scanning Electron Microscope),FT-IR(Fourier Transform Infrared spectoscopy),Zeta-potential,XPS(X-ray Photoelectron Spectroscopy),and wettability.Under the closed-circuit flotation flowsheet of"one roughing-two cleaning-three scavenging",aluminum concen-trate with a yield of 85.91%and sulfur content of 0.56%were obtained using a common collector.However,with the addition of the novel NPC,aluminum concentrate with a yield of 85.70%and sulfur content of 0.36%could be obtained by a simpler flowsheet of"one roughing-one cleaning-two scav-enging".The improvement in flotation performance is suggested to be contributed by the addition of spherical NPC,which induced a rougher and more hydrophobic pyrite surface.