The present invention relates to a coated granular substance, wherein the coating comprises a resin comprising the reaction product of a polyol component and an isocyanate component and cured by the addition of a catalyst, said catalyst comprising a hydroxy group-containing amine compound.;Further, the present invention relates to a process for coating a granular substance, comprising the steps of (a) providing a granular substance; (b) providing a polyol component and an isocyanate component; (c) optionally mixing the polyol component with the isocyanate component; (d) adding the mixture of step (c) or the polyol component and the isocyanate component as individual substances to the provided granular substance and producing a coating on the granular substance; (e) adding a catalyst to cure the coating; (f) optionally repeating steps (d) and (e), wherein the catalyst comprises a hydroxy group-containing amine compound.