复合激发煤气化渣基胶凝材料的制备

为提高煤化产业废渣、废水的综合利用，以煤气化渣为原料，高盐废水、水玻璃及石灰为复合激发剂制备胶凝材料。探究了复合激发剂中石灰掺量、水玻璃模数、水玻璃掺量及高盐废水掺量对胶凝材料力学性能的影响；借助XRD、SEM、MIP、ICP-AES等分析手段对激发剂作用下煤气化渣胶凝产物及其微观形貌进行表征,并讨论了胶凝材料对环境安全性的影响。结果表明，当石灰掺量为15%时，试样28 d抗压强度可达到23.8 Mpa；水玻璃模数为1.4时激发效果最好，水玻璃最佳掺量为13%；高盐废水掺量为100%时，试样28 d抗压强度为38.8 MPa。微观观察结果表明，水玻璃可促进煤气化渣硅铝玻璃体的溶解，提高水化产物聚合度，生成C-S-H、N-A-S-H使得体系的结构更加密实，后期强度增大。此外，复合激发剂在SO₄^2-、Cl^-、OH^-、Ca²⁺的共同作用下，可显著提高气化渣活性并加速其水化反应，生成Ca(OH)₂、C-S-H、钙矾石和水化氯铝酸钙等物质，使试样孔隙率降低，强度提高。并且，胶凝材料可固化高盐废水中的重金属。本研究结果可为煤气化渣制备胶凝材料提供参考。

Preparation of composite activated coal gasification slag-based cementitious materials

In order to improve the comprehensive utilization of the waste slag and wastewater produced by the coal chemical industry, the cementitious material was prepared with coal gasification slag as raw material and high salt wastewater, water glass and lime as composite activator. The activated effects of lime content, sodium silicate modulus, sodium silicate content and high salt wastewater content in the composite activator on the mechanical properties of the cementitious materials were explored, and the cementitious products of coal gasification slag and their microscopic structure were tested by XRD, SEM, MIP, ICP-AES and other methods. Finally, the environment safety of the cementitious materials was discussed. The results showed that the 28 d compressive strength can reach 23.8 MPa when the lime content was 15%. When the sodium silicate modulus was 1.4, activation effect is the best, and the optimum content of water glass was 13%. When the high salt wastewater content was 100%, the 28 d compressive strength of the specimen was 38.8 MPa. Microscopic results showed that sodium silicate can promote the dissolution of silicon-aluminum glass in coal gasification slag, improve the polymerization of hydration products. The generation of C-S-H, N-A-S-H made the structure of the system denser, which leaded to the later strength increases. In addition, the composite activator can significantly increase the activity of gasification slag and accelerate its hydration reaction under the joint action of SO42-, Cl-, OH-, and Ca2+ to produce Ca(OH)2, C-S-H, ettringite, and hydrated calcium chloroaluminate. The increased hydration products reduced the porosity of the samples, which improving the strength of the samples. And, cementitious material can solidify heavy metals in high-salt wastewater. The results of this study can provide theoretical reference for the preparation of cementitious materials from coal gasification slag.