铁尾矿替代粉煤灰制备蒸压加气混凝土试验研究

基于收集到的鞍钢、首钢、燕钢铁尾矿，在组成特性分析的基础上，以其为原料替代粉煤灰制备蒸压加气混凝土，并分别对试样干密度、抗压强度、导热系数、产物组成及微观形貌进行研究。结果表明，燕钢尾矿中SiO₂含量仅为45.1%，且主要以低活性的辉石形式存在。相比之下，鞍钢尾矿、首钢尾矿中SiO₂含量分别为80.0%、72.6%，且主要以石英形式存在，属高硅质尾矿，可用作蒸压加气混凝土的硅质原料。当采用50%鞍钢尾矿、首钢尾矿分别等量替代粉煤灰时，可成功制备干密度达到B06等级、抗压强度达到A5.0等级的蒸压加气混凝土。鞍钢尾矿、首钢尾矿制备蒸压加气混凝土的主要反应产物分别为带状、片状的托贝莫来石晶体。

Study on preparation of autoclaved aerated concrete using iron tailing as replacement of fly ash

The iron tailings are collected from Ansteel Group, Shougang Group, and Yangang Group, respectively. Based on the compositions analyses of iron tailings, aerated autoclaved concretes (AACs) are prepared with iron tailings by replacing fly ash. Then the dry density, compressive strength, thermal conductivity coefficient, reaction products, and morphologies are investigated. The results show that the Yangang tailing contains only 45.1% SiO2, which mainly exists in the form of low-activity augite. In contrast, the SiO2 content of Angang tailing and Shougang tailing, which mainly exists in the form of quartz, is 80.0% and 72.6%, respectively. The high SiO2 content makes Angang tailing and Shougang tailing suitable as the siliceous materials to prepare AACs. As 50% Angang tailing and Shougang tailing are respectively used to replace fly ash, the dry density of AACs reaches B06 grade and the compressive strength meets A5.0 grade. The main reaction products of AACs prepared from Angang tailing and Shougang tailing are belt- and flake- like tobermorite crystals.