Quantum Weyl reciprocity relates the representation theory of Hecke al
gebras of type A with that of q-Schur algebras. This paper establishes
that Weyl reciprocity holds integrally (i. e., over the ring Z[q, q(-
1)] of Laurent polynomials) and that it behaves well under base-change
. A key ingredient in our approach involves the theory of tilting modu
les for q-Schur algebras. New results obtained in that direction inclu
de an explicit determination of the Ringel dual algebra of a q-Schur a
lgebra in all cases. In particular, in the most interesting situation,
the Ringel dual identifies with a natural quotient algebra of the Hec
ke algebra.