碱激发高炉矿渣-粉煤灰制备充填胶凝材料

以河南某材料公司的高炉矿渣和粉煤灰为原料,NaOH溶液为碱激发剂,对山东某金属矿山的尾砂进行胶结充填体强度试验。结果表明,在高炉矿渣与粉煤灰的质量比为4,NaOH浓度为8 mol/L,液固质量比为0.5情况下,充填材料试件3 d、28 d的抗压强度分别为2.12和6.84 MPa,满足充填要求。SEM分析表明,高炉矿渣和粉煤灰在碱激发后生成大量的凝胶相,是充填材料试件产生强度的主要原因;XRD和FTIR分析表明,碱激发材料中出现了水化硅酸钙的晶相峰,Si(Al)—O—Si在碱激发作用下发生解聚后又重新聚合形成SiO_4],以及碱激发后的材料体系吸收空气中的CO_2生成碳酸盐矿物,是净浆试件强度的主要来源。

Preparation of Binding Materials for Backfilling with Alkali Activated Blast Furnace Slag and Fly Ash

Using blast furnace slag and fly ash from a material company in Henan as raw materials,NaOH solution as al-kali activator,the strength test of cement filling body for the metal mine tailings in Shandong is conducted. The results showed that when blast furnace slag/fly ash mass ratio was 4,NaOH concentration was 8 mol/L and liquid/solid mass ratio was 0. 5, the 3 d and 28 d compressive strength of cement filling material was 2. 12 and 6. 84 MPa respectively,which meets the require-ments of backfilling. SEM analysis shows that a large number of gel phase is generated after alkali activation,which is the main reason for improving strength of the filling materials. XRD and FTIR analysis showed that the crystal phase peaks of hydrated calcium silicate appeared in the Alkali activated material. SiO4 ] is reconstituted after the depolymerization of Si( Al)—O—Si under the activation of alkali solution and furthermore,carbonate minerals were formed in Alkali activated material through the adsorption of CO2 from atmosphere. All these were the sources of strength of the test specimens.