Mixer for ceramic feedstock pellets with a tank, a mixing means, and heat exchange means including cooling means for the cooling of the content of this tank.Control means control the heat exchange means which include heating means arranged to heat the content of this tank to a temperature comprised between a lower temperature (TINF) and a higher temperature (TSUP) stored in a memory for a specific mixture, and the heating means exchange energy with a heat exchange and mixing temperature maintenance circuit, external to this tank, and wherein the thermal inertia of this circuit is higher than that of this fully loaded tank.The invention also concerns a method for mixing raw material for powder metallurgy, implementing a specific injection moulding composition and a specific binder.