• Resources Recycling
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• v.26 no.5
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• pp.97-104
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• 2017

Nuclear fuel cladding tubes are manufactured through pilgering and the annealing process. In order to remove the oxidized layer and impurities on the surface of the tube, a pickling process is required. Zirconium (Zr) is dissolved in a HF and $HNO_3$ acid mixture during the process and the pickling waste acid, including the dissolved Zr, is completely discarded after neutralization. This study observes the effects of the residual impurities (Ba) in the pickling solution regenerated from the $BaF_2$ precipitation process on the waste pickling solution. In addition, the concentration of Ba and Zr for the actual nuclear fuel cladding tube process was optimized. The regenerated pickling solution was tested through a pilot plant pickling process device that simulates the commercial pickling process of nuclear fuel cladding tubes, and the pickling efficiency was analyzed through AFM analysis of the roughness of the cladding tube surface.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.109-116
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• 2021

In order to replace mineral aggregate used as road pavement materials with steel slag aggregate, this present study evaluated mechanical properties of SMA Concrete mixtures using steel slag aggregate as oxidized slag from electric furnace in iron works. The variables of this experiment are the aggregate type of mineral and steel slag and the sieve sized of 10mm and 13mm. The physical properties inclu ding the specific gravity and absorption rate etc. of the slag aggregate mixtu res satisfied the KS standard as asphalt mixtu re. As a resu lt of evalu ating the mechanical properties of the asphalt mixtures, the optimum asphalt content of the slag aggregate mixtures were lower than that of the mineral aggregate mixtures, but other quality standards were all satisfied. In the deformation strength evaluation, the slag aggregate mixtures were measu red slightly higher than that of the mineral aggregate mixtu res, and the dynamic stability test satisfied the 2,000pass/mm standard value in all specimens. And, the moduli of resilient of the slag aggregate mixtures showed an improved value compared with the mineral aggregate mixtures. Therefore, as the resilient rate of the slag aggregate mixtures improved, it is speculated that there will be an effect of improving public performance according to the repeated traffic load of the vehicle.