  Hysteresis loops are obtained in the Ising spin-glass phase in d=3, using
frustration-conserving hard-spin mean-field theory. The system is driven by a
time-dependent random magnetic field H_Q that is conjugate to the spin-glass
order Q, yielding a field-driven first-order phase transition through the
spin-glass phase. The hysteresis loop area A of the Q-H_Q curve scales with
respect to the sweep rate h of magnetic field as A-A_0 = h^b. In the spin-glass
and random-bond ferromagnetic phases, the sweep-rate scaling exponent b changes
with temperature T, but appears not to change with antiferromagnetic bond
concentration p. By contrast, in the pure ferromagnetic phase, b does not
depend on T and has a sharply different value than in the two other phases.
