赤泥制备碱激发胶凝材料的性能

Properties of alkali-activated cementitious materials synthesized with red mud

分别以拜耳法赤泥、烧结法赤泥为原料,进行碱激发胶凝材料的制备研究,并对其制备碱激发胶凝材料的可行性进行了评价。研究结果表明,拜耳法赤泥的胶凝活性极低,不适宜用作碱激发胶凝材料的制备原料;烧结法赤泥因含有具有一定胶凝活性的β-硅酸二钙,因此可用作碱激发胶凝材料的制备原料。以烧结法赤泥和矿渣组成二元复合体系,以模数2.40的液体水玻璃为激发剂制备碱激发胶凝材料,在矿渣掺量30%、赤泥掺量70%的条件下,激发剂的最佳掺量为5.0%。所制备碱激发砂浆试样的3d、28d抗压强度可分别达到35.0 MPa、65.0 MPa以上。

Alkali-activated cementitious materials were synthesized with Bayer red mud and sintering red mud,respectively, and the feasibilities were evaluated.The results showed that the Bayer red mud had barely pozzolanic activity, and therefore was unsuitable for the synthesis of alkali-activated cementitious materials.The β-C2 S in sintering red mud offered the possibility of the synthesis of alkali-activated cementitious materials. When the sintering red mud-slag blend with a mass ratio of 7：3 was activated by sodium silicate（which had a module of 2.4）,the optimized content of sodium silicate was 5.0%.under this condition, the compressive strength of alkali-activated mortars synthesized reached 35.0 MPa at 3d and 65.0 MPa at 28 d,respectively.