Process for the production of metal soaps

A process for the production of a solid metal soap of the formula

• M(R--COO)(R"--COO)
• in which M represents at least one metal cation selected from the group consisting of Ca, Mg, Cd, Ba, Zn, and Pb and R and R.sup.1 represent independently selected C.sub.8-34 hydrocarbon radicals, by direct synthesis from at least one fatty acid with metal oxides and/or metal hydroxides, which comprises:
• maintaining a reaction zone containing a liquid phase comprising at least one fatty acid under reduced pressure;
• passing a portion of the liquid phase to an external premixing zone;
• introducing a solid metal oxide and/or metal hydroxide into the liquid phase in the premix zone to form a mixture;
• passing this mixture to the reaction zone through an intensive mixing zone;
• and continuously removing water of neutralization formed by reaction between at least one fatty acid with metal oxides and/or metal hydroxides from the reaction zone as a gas phase.