In this article we report a new chelating fiber that was prepared from a hydrolyzate of poly(N-vinylformamide/acrylonitrile) by a wet-spinning method. This fiber contains chelating groups, such as amidine groups, amino groups, cyano groups, and amide groups, with high densities. We examined the chelating abilities for several metal ions with this fiber, and present the morphological merit of the fibrous product compared with the globular resin. Based on the research results, it is shown that the fiber has higher binding capacities and better adsorption properties for heavy metal ions than the resin. The pH value of the metal ion solution shows strong influences on the adsorption of the metal ions. The maximum adsorption capacities of the fiber for Cu 2ϩ , Cr 3ϩ , Co 2ϩ , Ni 2ϩ , and Mn 2ϩ are 112.23, 88.11, 141.04, 108.06, and 73.51 mg/g, respectively. In mixed metal ions solution, the fiber adsorbs Cr 3ϩ , Cu 2ϩ and Co 2ϩ efficiently. The adsorbed metal ions can be quantitatively eluted by hydrochloric acid.
To introduce feature and microstructure of edge crack of rolled coil, character and distribution of transverse corner crack of continuous cast slab (hereafter referred to as transverse corner crack), trace out rolling process of defective continuous cast slab, transverse corner crack of slab causes edge crack of rolled coil, the corner inclusions of slab and rolling process are also significant factors. To give some suggestions to resolve two dimensional heat transfer and high cooling intensity about control of transverse corner cracks. Inclusions cause stress concentration to lead to edge cracks of coils. Edge cracks of coils are related to transverse corner cracks of slabs, but not an exact one-for-one relation. Tiny transverse corner cracks may be removed by scarfing or furnace. Uneven or low temperature of the edge of rolled piece cause uneven extension of edge metal to form “fold”, namely “edge filament”. By research and practice, the quality of slab has been substantially improved in Shougang Qiangang.
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