We study the interplay between antiferromagnetism and superconductivity in a generalizedinfinite-UAnderson lattice, where both superconductivity and antiferromagneticorder are introduced phenomenologically in mean field theory. Ina certain regime, a quantum phase transition is found which ischaracterized by an abrupt expulsion of magnetic order by d-wavesuperconductivity, as externally applied pressure increases. This transition takes place when thed-wavesuperconducting critical temperature, Tc,intercepts the magnetic critical temperature, Tm,under increasing pressure. Calculations of the quasiparticle bands and density of statesin the ordered phases are presented. We calculate the optical conductivity σ(ω)in the clean limit. It is shown that, when the temperature drops below Tm,a double peak structure develops in σ(ω).