In order to expand the application of the electrodeposited Ni-Fe alloy foil,their mechanical and magnetic properties were studied after heat treatment.The development of grain growth during annealing was in-situ online investigated using a heating stage microscope,and the texture was analyzed via X-ray diffraction（XRD）and electron back-scattered diffraction（EBSD）.The results indicated that abnormal grain growth usually occurred during annealing at 1000-1050°C.The{111}oriented grains preferentially grew as the annealing temperature and holding time increased.The plasticities of the electrodeposited Ni-Fe alloy foils after heat treatment were better than those of the original samples.The excellent ductility was obtained without a loss in magnetic properties after annealing at 1100°C for 6h.
The vanadium titano-magnetite （VTM） iron ore fines of 110--150/xm in diameter were reduced in a trans- parent quartz fluidized bed by 70 %CO-30 % H2 （volume fraction） mixtures. MgO powders served as coating agent to solve sticking problem. Two coating methods were introduced in this experiment： high temperature injection method and briquetting→oxidizing roast→crushing method. According to the experimental results, the minimum effective coating amount of MgO was 0. 1 mass%. The metallization ratio （MR） of the product rose from around 58% to above 90% with the above treatments. To investigate the sticking mechanism of fine ore, the morphology evolution was in- vestigated. Instead of iron whiskers, an interlaced fibrous porous surface formed. The ulvospinel （2FeO ： TiO2 ） in VTM is more difficult to be reduced than FeO according to thermodynamic calculation. XRD results showed that MgO diffused into Fe203 lattice before forming pleonaste （MgO · Fe2O3 ） during oxidizing roast at 1273 K. The melting point of the pleonaste is 1986 K and that made contribution to prevent the sticking problem.
Lei GUOJin-tao YUJing-kun TANGYin-he LINZhan-cheng GUOHui-qing TANG
