Increase in concentration of carbon dioxide in air, which is one of the greenhouse gases, causes the global warming. The study and development on the separation, absorption and fixation of carbon dioxide have been performed. On the other hand, slag is constantly discharged from the steel industries, and a large quantity of concrete (cement) will be wasted in future. Those materials contain calcium oxide which is easily reacted carbon dioxide. Therefore, I develop the technology to fix carbon dioxide in them.
The quantity of absorption of carbon dioxide in steel making slag under wet grinding is larger than that under dry grinding. The quantity of absorption and fixation of carbon dioxide is larger than the quantity of carbon dioxide which is exhausted from the reactor under operation. (Figure 1).

1) M.N.N.Hisyamudin（博士課程）, S.Yokoyama and M.Umemoto:”Storage of CO2 in Low Al2O3 EAF Oxidizing Slag by Grinding with Vibration Mill”, Materials Science Forum, Vol.634-636 (2010), p.2927-2930
2) S.Yokoyama, R.Sato, N.H.B.M.Nor（博士課程）, M.Umemoto: “Behavior of CO2 Absorption in Wet-grinding of Electronic Arc Furnace Reduction Slag by Vibration Ball Mill”, ISIJ International, Vol.50 (2010), No.3, p.482-489

A large amount of slag is drained as a by-product from iron and steel industries. The development of is the new practical use technology of the slag demanded due to lack of the last disposal ground. As one of the usages, it is thought to use the slag as cover sand materials to ooze in waters. In this study, I perform an elution test of the slag to check the safety of the slag and to investigate the dissolution behavior of the slag into fresh and sea water. In addition, the slag contains valuable and harmful components. Separation and extraction of them from the slag have been studied.

1) S.Yokoyama, A.Suzuki, N.H.B.M.Nor（博士課程）, H.Kanematsu, A.Ogawa, T.Takahashi, M.Izaki and M.Umemoto: “Serial Batch Elution of Electronic Arc Furnace Oxidizing Slag Discharged from Normal Steelmaking Process into Fresh Water”, ISIJ International, Vol.50 (2010), No.4, p.630-638
2) S.Yokoyama，A.Suzuki，M.Izaki，M.Umemoto：“Elution behavior of Electric Arc Furnace Slag in Fresh Water”，Tetsu-to-Hagane，Vol.95 (2009), No.5, p.434-443

About 5,000,000 cars a year become the end of life vehicles now in Japan. As recycling of them, I perform the development of the dismantling tool for removal of the windshields from a car (Figure 3). In addition, I develop the new process using a rolling machine or mixer to separate copper wire mechanically from a wire harness that is used in a car. I investigate the effect of temperature, length and etc. of the wire harness on the recovery ratio.

1) S. Yokoyama, S. Takeuchi, M.N.N.Hisyamudin（博士課程）:“Mechanical Separation of Metallic Copper from Polymer-Insulated Copper Wire”, International Conference on Advanced Materials and Processing Technology (AMPT2010), Paris, (France), 24?27 October 2010，AIP Conference Proceedings Vol. 1315, p.1527-1532
2) S. Yokoyama, S. Takeuchi, H. Hashimoto, S. Maki: “Mechanical Separation of Metallic Copper from PVC(polyvinylchloride) Coated Copper Wire of Wire Harness by Rolling”, Proceedings of the International Federation of Automotive Engineering Societies (FISITA-2006), Yokohama, (CD ROM)