Effect of Sodium Silicate on the Hydration of Alkali-Activated Copper-Nickel Slag Materials

Abstract

This paper studied the influence of the modulus and dosage of sodium silicate on the hydration of alkali-activated copper-nickel slag (CNS) materials. CNS was used as the main raw material, and ground granulated blast furnace slag (GBFS) powder was selected as the mineral additive. The hydration and hardening mechanisms were discussed. The experimental results showed that [SiO4]4− and [AlO4]5− with a high degree of polymerization in the CNS glassy phase more easily underwent depolymerization-condensation and produced more C-S-H gels when the modulus was small and the sodium silicate dosage was high. When the content of sodium silicate was 7.0% and the modulus of sodium silicate solution was 1.0, the 28-day compressive strength of the material reached 125 MPa. This alkali-activated copper-nickel slag material can be used for mine filling, which has certain economic and ecological benefits.

Keywords

• copper-nickel slag
• alkali-activated materials
• sodium silicate
• hydration