Development of High Strength Materials from Steel Slags

有许多副产品还没有被使用。随着工业活动的增加，这些材料的数量变得越来越多。从节约能源和资源的角度来看，这些材料的使用是可取的。日本每年生产的钢渣约为1000万吨，由于其化学成分多种多样，很难用作工业材料。控制人类活动产生的CO_2气体排放也是保护温室效应的世界性难题之一。另一方面，3CaO-SiO_2、2CaO-SiO_2等含CaO较多的化合物通过碳化反应可制得高强度材料。钢渣的主要成分是3CaO-SiO_2和2CaO-SiO_2。本研究项目的目的是开发利用钢渣副产物和固化CO_2气体制备高强度材料。玻璃纤维混凝土应用于玻璃纤维混凝土和人造砂两大类。由于基质的高碱度，玻璃纤维混凝土需要昂贵的高耐碱玻璃纤维。由碳酸盐矿渣制成的基质碱度低，可以用普通的低成本玻璃纤维代替昂贵的高耐碱玻璃纤维用于GFRC，基质质量分数约为10×10。普通碱性钠玻璃的耐久性是水化基质的5倍左右。天然砂和骨料资源量减少，海砂的收集在日本许多地区受到抑制。高质量的人工砂是人们所期望的。结果表明，碳化渣是一种人工砂，由矿渣粉碳化而成，当使用日本生产的1/3的钢渣作为原料时，日本1995年的二氧化碳排放量将减少0.03%。

There are many by-products which has not been used. The amount of these materials become more and more with high industrial activity. The use of these materiarls has been desired on the point of view of saving energy and resourses. The steel slags are produced about 10 million tons in a year in Japan, and they are not easy to use for industrial materials because of variety in their chemical composition. The regulation of CO_2 gas emission owing to high human activity is also one of very important world wide problems for protection of Green House Effects. On the other hand, it has been known that the compounds which contains much amount of CaO such as 3CaO SiO_2 and 2CaO SiO_2 makes high strength materials by carbonation. The main components of steel slags are 3CaO SiO_2 and 2CaO SiO_2.The aim of this research project is in the development of manufacturing high strength materials with using by-product of steel slags and solidifying the CO_2 gas. It has been applied in two category as GFRC and artificial sand.Glass fiber reinforced concrete needs expensive high-alkaline-resistant glass fiber because of high alkalinity of matrix. The matrix which is made from carbonated slag has low alkalinity, so usual low-cost glass fiber instead of expensive high-alkaline-resistant glass fiber can be used for GFRC.The matrix is about 10 in pH.The usual alkaline sodium glass showed longer durability about 5 times than in hydrated matrix.The amount of resources of natural sand and aggregate becomes small and the collection of sea sand becomes to inhibit in many regions in Japan. The artificial sand with high quality is desired. It was shown that the carbonated slag is available as artificial sand, which is obtained by carbonation of granulated slag powder.When the one third of steel slags produced in Japan is used as these materials, the 0.03% of the amount of CO_2 gas emission at 1995 in Japan will be reduced.