Alkali-free, alkaline metal-free, and chloride-free setting and hardening accelerator for hydraulic binders

摘要

An alkali-free, alkaline meta-free and chloride-free setting and hardening accelerator for hydraulic binders comprising at least one water soluble fluoride comprising aluminum salt and at least one water soluble sulfate comprising aluminum salt. A method for the production of such an accelerator described herein, where the water soluble fluoride comprising aluminum salt is produced by combining an aluminum compound such as amorphous aluminum hydroxide, crystalline aluminum hydroxide, aluminum oxide or mixtures thereof with hydrofluoric acid, optionally at enhanced temperature, prior to the blending with other components and then optionally drying.