the invention relates to the production of solid , powdery carboxylates of rare earth elements , particularly nd , la , pr , and ce , where the ligands coordinated to the metal are preferably long chain , branched carboxylic acids , most preferably 2 - ethylhexanoic , neodecanoic and naphthenic acids . the process involves batch precipitation of the product by utilizing rare earth water soluble salts , preferably rare earth nitrates , and salts of the carboxylic acid and washing the product with water , alcohol , water and alcohol mixtures or combinations thereof .