To effect precipitation of the alkaline earth salts of the acids so that phase separation as described in United States Patent 2,516,126 (abs. 2015) can take place, certain low-boiling solvents are added to the mixtures of H2O-insoluble nonacid oxygenated organic C4+ compounds. The addition of the solvent gives a phase separation, the upper phase containing oxygenated compounds substantially free of acids and acid salts, dissolved in the solvent, and the lower phase containing all of the acids present in the original mixture in the form of their corresponding alkaline earth salts and the remaining oxygenated compounds. The solvent is a H2O-insoluble organic C3-C12 compound, such as a hydrocarbon or a mixture of saturated and unsaturated hydrocarbons, or an O2-containing organic compound, such as an ether or a ketone. 5 United States patents cited.