The invention relates to a method for the dry slaking of calcium oxides and magnesium from calcomagnesian compound containing preferably at least 10 wt. % of MgO in relation to the total weight of said calcomagnesian compound, in which calcomagnesian compound is supplied to a slaking vessel, a slaking aqueous phase is supplied to the slaking vessel, followed by slaking the calcomagnesian compound delivered to the slaking vessel, by means of the slaking aqueous phase, and forming hydrated solid particles of calcium hydroxides and magnesium, in the presence of an additive. The invention also relates to the compound produced in this way.