Rheological performance and hydration kinetics of lithium slag-cement binder in the function of sodium sulfate

Effects of Na₂SO₄ on rheological performance and hydration kinetics of lithium slag (LS) binder were investigated. Results showed that Na₂SO₄ impaired the viscosity property of LS-cement binder. Increased dosage of Na₂SO₄ led to increased consistency coefficient (K) and declined flow behavior index (n), indicating enhanced viscosity and reduced flow behavior of LS-cement binder in the function of Na₂SO₄. A high amount of Na₂SO₄ led to a relatively high hydration degree during the transformation process of NG to I and the transformation process of I to D. Increased dosage of Na₂SO₄ led to the raised value of K _A–B, higher hydration peak ((dQ/dt)_C), and decreased value of n, referring to enhanced nucleation rate of C–S–H, increased total nuclei number at the early acceleration stage. Na₂SO₄ advanced the hydration of LS-cement binder, shortened introduction period, advanced acceleration period, and accelerated hydration process with enhanced formation of C–S–H and AFt, which contributed to compacter matrix with denser microstructure and higher mechanical strength.