A method for producing basic products from ash, which includes the provision of a starting material in particle form, crushing the particles of the starting material by high-frequency pressure impulses and the in situ separation of at least two fractions with different average particle sizes, where the energy-efficient production of a basic product with a defined particle size and high reactivity is effected, such that the produced basic products can be used directly for further product production, e.g. as alkalizing agent, for ground stabilization or as filler.