A solidification and curing accelerator for hydraulic binders produced by a process including providing a reaction mixture composed of constituents (a) - (e) as follows: (a) at least one of basic aluminum salts which are substantially water insoluble and aluminum hydroxide; (b) at least one of aluminum sulfate which is substantially water soluble and sulfuric acid; (c) at least one of an organic carboxylic acid or mixtures of at least two organic carboxylic acids; (d) aluminum salts of organic carboxylic acids; and (e) at least one organic and inorganic substance selected from the group consisting of sulfates, hydrogen-sulfates, carbonates, hydrogen-carbonates, alkaline earth metal oxides, and alkaline earth metal hydroxides; adding water to the reaction mixture and reacting at a temperature ranging up to 150 ° C. for a time effective to provide a reaction product which is a solution in water.