A process and method for producing a crystallized metal sulfate. The crystallized metal sulfate may be battery-grade. The method may comprise receiving a metal ion-containing stream and crystalizing a metal sulfate from the stream. The process may comprise receiving a stream from a metal processing plant, and crystalizing a metal sulfate from the stream. The process may be a metal electrowinning process comprising crystalizing a metal ion-containing stream to form a crystallized metal sulfate in a mother liquor. The process or method may comprise returning the mother liquor upstream or to the metal electrowinning process.