水熱ホットプレス法による高炉スラグを原料とした微細孔を有する固化体の作製および熱伝導率測定

摘要

To produce insulating construction materials using hydrothermal reaction from blast furnace slag (BF slag) such as air-cooled, air granulated, and water-cooled slags, we investigated the fabrication of porous solidified materials from BF slag by a hydrothermal hot-pressing method. The thermal conductivity of the solidified materials was also investigated. The experimental conditions were; hydrothermal holding time from 0 to 120min, hydrothermal temperature from 250 to 350℃, hydrothermal pressure from 20 to 80MPa, and slag powder sizes less than 15μm, 39±24μm, 84±21μm, 178±72μm, 375±125μm and more than 500μm. It was found that growth of the hydrothermally reacted phase led to a higher density and higher thermal conductivity of the solidified materials. It was noteworthy that the thermal conductivity of the hydrothermal solidified materials became smaller when the size of the slag powder was larger. This was because the more porous structure introduced into the solidified materials resulted in a lower density of the solidified materials. It was also found that glassy slag such as water-cooled and air granulated slags can be solidified even if the size of the slag powder was more than 500μm.%日本の粗鋼生産量は年間1億トン程度であるが，その過rn程では約3500万トンものスラグが副生している。高炉スrnラグはこれまで100％近くが再利用されてきたが，他のリrnサイクル資材との競合などもあり，更なる高付加価値再生rn化が望まれている。大量に生成するスラグに見合った需rn要を考えると，機能性建材への応用がその候補として挙げrnられる。