Method for the manufacture of hydraulic binders from water treatment residuals

A method for the manufacture of a high alumina hydraulic binder comprising hydrating a source of aluminium ions with a source of calcium ions in the presence of water to form mineral hydrates and subsequently heating said mineral hydrates to form said high alumina hydraulic binder, wherein said source of aluminium ions comprises drinking water treatment residuals, wherein organic material present in said drinking water treatment residuals forms a source of fuel energy during said heating, wherein air or oxygen are added to the mixture during said heating to facilitate oxidation of said organic material.