富镁镍渣-粉煤灰基地质聚合物的制备及性能

Preparation and properties of high⁃magnesium nickel slag⁃fly ash based geopolymer

通过在富镁镍渣中引入MgO并重熔水淬,研究了活化处理过程对富镁镍渣活性的改善作用,并以水玻璃作为激发剂研究了活化处理后的富镁镍渣作为胶凝材料的工程性能和水化产物。结果表明:活化处理后的富镁镍渣基地质聚合物抗压强度可达35.60 MPa,较未活化处理的富镁镍渣基地质聚合物提升60.7%;影响地质聚合物抗压强度因素的主次顺序依次为水玻璃掺量、m(富镁镍渣)∶m(粉煤灰)、水玻璃模数;主要水化产物为钠镁铝硅酸盐凝胶(N-M-A-S-H),还有少部分铝硅酸盐及水化硅酸钙等组成的凝胶相和结晶相,未发现Mg(OH)_(2);此外,大量的N-M-A-S-H胶凝相包裹着未反应的粉煤灰形成致密的凝胶-晶相结构。该研究为富镁镍渣作为原料制备地质聚合物的实际应用提供了一定的指导,并为提高矿渣的火山灰活性提供了一种新思路。

The improvement of the activation treatment on the activity of high-magnesium nickel slag was investigated by in-troducing MgO in high-magnesium nickel slag and remelting it with water quenching,and the engineering performance and hydration products of activated high-magnesium nickel slag as cementitious material were studied using water glass as the activator.The results showed that the compressive strength of high-magnesium nickel slag based geopolymer after activation treatment could reach 35.60 MPa,which was 60.7%higher than that of untreated high-magnesium nickel slag-based geo-polymer.The factors affecting the compressive strength of geopolymers in order of predominance were water glass dosing,m(high-magnesium nickel slag)∶m(fly ash),and water glass modulus.The main hydration products were sodium-magne-sium-aluminum silicate gel(N-M-A-S-H),and a small portion of aluminosilicate and hydrated calcium silicate,etc,with-out Mg(OH)_(2).A large number of gelling phases such as N-M-A-S-H wrapped around unreacted FA,etc.to form a dense gel-crystal phase structure.This study provided some guidance for the practical application of high-magnesium nickel slag as raw material for the preparation of geopolymers,and provided a new idea for improving the pozzolanic activity of slag.