  We consider two mechanisms of spin relaxation in disordered graphene. i) Spin
relaxation due to curvature spin orbit coupling caused by ripples. ii) Spin
relaxation due to the interaction of the electronic spin with localized
magnetic moments at the edges. We obtain analytical expressions for the spin
relaxation times, tau_SO and tau_J due to both mechanisms and estimate their
values for realistic parameters of graphene samples. We obtain that spin
relaxation originating from these mechanisms is very weak and spin coherence is
expected in disordered graphene up to samples of length L ~ 1 micron.
