利用粉煤灰制备高强矿物聚合材料的实验研究

Preparation of High-strength Mineral Polymer Based on Flyash:An Experimental Study

以粉煤灰和内蒙古白云鄂博的富钾板岩提钾后的硅铝质滤渣为粉体原料,标准砂为骨料,采用振动成型方法,在90℃下养护24 h,制备了矿物聚合材料。实验结果显示:制品的7 d饱水抗压强度达78.5 MPa,28 d饱水抗压强度可达89.0 MPa;制品的含水率和吸水率分别为5.3%和15.0%;在20℃下,制品在浓度为1.0 mol/L的硫酸溶液中浸泡24 h,其质量损失率为2.1%。以制品的抗压强度为指标,研究了主要因素(提钾滤渣比例、固液质量比、硅酸钠含量和标准砂含量)对制品性能的影响。结果表明:干燥的提钾滤渣在粉体物料中的比例对制品的力学性能影响最大;硅酸钠水玻璃在液相中的比例约为70%,且标准砂占固相的比例为70%左右时,可制得力学性能良好的矿物聚合材料。矿物聚合材料的固结过程为:硅铝质原料在碱硅酸盐溶液中先分解为铝硅酸盐低聚体,低聚体再通过脱羟基聚合反应生成铝硅酸盐胶体相,进一步形成由[S iO4]4-和[A lO4]5-四面体相互连接的具有三维网络结构的矿物聚合材料基体相,从而赋予制品良好的力学性能。

The flyash and leached alumino-siliceous residue distilled from a kalisalt from Bayan Obo of Inner Mongolia, with standard sand as aggregate, were used as principal materials to prepare mineral polymer. Quiver moulding method was adopted to manufacture the mineral polymer, and the module was curing at 90 ℃ in drying oven. The compressive strength of the products reach up to 78.5 MPa and 89. 0 MPa respectively for those cured for 7 days and 28 days. The water content and water absorbability of the representative products were 5.3% and 15.0% respectively, and the mass loss of the product was 2. 1% while the specimen was inundated in sulfuric acid solution with a concentration of 1.0 mol/L for 24 hours at 20 ℃. The current experimental results show that the content of leached alumino-siliceous residue distilled from the kalisalt was the primary effective factor on the mechanical properties of the products. while the content of sodium silicate in the alkaline liquid High performance mineral polymer can be prepared and the standard sand in the solid materials are both kept around 70%. During the solidification of the mineral polymer products, both silicate and aluminate oligomers formed by Si-Al materials in the alkaline solution produced aluminosilicate gel by dehydroxy polymerization, then transformed into a three-dimension network structure matrix with Si-O-Al-O bonds, leading to excellent mechanical properties for the mineral polymer products as-prepared in the current study.