Reactors, reactor systems and methods for producing particles in a precipitation process are provided. The reactor includes a housing defining a reaction chamber, a stator assembly including two or more stators, a rotor assembly including two or more rotors, the rotor assembly configured for rotation about an axis of rotation relative to the stator assembly, a first inlet to supply a first reactant material to the reaction chamber at a first radial location, a second inlet to supply a second reactant material to the reaction chamber at a second radial location different from the first radial location, wherein the first and second reactant materials react to produce precipitation of particles in the reaction chamber, and an outlet to supply the particles formed in the reaction chamber.
