  We study stochastic particle systems on a complete graph and derive effective
mean-field rate equations in the limit of diverging system size, which are also
known from cluster aggregation models. We establish the propagation of chaos
under generic growth conditions on particle jump rates, and the limit provides
a master equation for the single site dynamics of the particle system, which is
a non-linear birth death chain. Conservation of mass in the particle system
leads to conservation of the first moment for the limit dynamics, and to
non-uniqueness of stationary distributions. Our findings are consistent with
recent results on exchange driven growth, and provide a connection between the
well studied phenomena of gelation and condensation.
