Effect of activators, admixtures and temperature on the early hydration performance of desulfurization ash

•Different activators on the properties of the desulfurization ash are explained.•Pozzolanic reactivity and mechanical property of desulfurization ash is studied.•Different hydration products are detected by testing methods.

The methods of activators, active mineral admixtures and temperature were used to activate the pozzolanic and self-cementitious properties of desulfurization ash, as well as to compare and analyze the 7 days and 28 days compressive strengths of desulfurization ash mortar. Meanwhile, the early hydration process and hydrated products of desulfurization ash were analyzed with X-ray diffraction analysis (XRD), FT-IR spectra (FT-IR) and scanning electron microscopy (SEM). The research results show that different kinds of activators and active mineral admixtures can activate the early active of desulfurization ash, as follows, the first is quicklime, then sodium silicate, slag powder, triethanolamine, Na2SO4 and the last is silica. By the combination of organic chemical activators and inorganic mineral admixtures mentioned above, the 7 days and 28 days compressive strengths of desulfurization ash mortar can be up to 20 MPa and 22.3 MPa, respectively. The strength can still be raised by enhancing the proper curing temperature.