The gypsum-free portland cement hydration and thermal properties

The ground clinker (without gypsum) + ligninsulfonate (sulfonated polyphenolate) + alkali metal salts (carbonate, bicarbonate, silicate) represents a new type of binding agent (gypsum-free portland cement, GF cement) that differs from the conventional portland cement in its short- and long-term strength and resistance to high temperatures (to 1450°C). The GF cement processed at low water/cement ratios shows a different progress of hydration (RTG, TA, SEM study) and different development of microstructure than the portland cement (absence of portlandite crystals). The GF cements had been used with success as refractory materials in the steel industry.