The most important solution in the new sodium chromate production process implemented in Alwernia Chemical Works is in-process recycling of chromic mud. It allows to decrease the hazard to natural environment resulting from released chromic waste. It also involves economical advantages. The paper presents studies on the optimisation of this process with the use of a fuzzy logic method. The influence of the grain size of chromic mud on the sodium chromate production process with chromic mud in process recycling has been estimated. The optimal values of the process parameters can be achieved applying preliminary ground chromic mud and fine-ground fractions of chromic ore. "Deep" milling of chromic mud is not necessary.