This is recrystallized and roasted to vanadium pentoxide, which is then suspended in water into which ammonia is passed, when ammonium metavanadate is again formed and may be purified by recrystallization.
The electrolyte, when too impure for further use, is commonly recrystallized, or electrolysed with insoluble anodes to recover the copper.
Meta-dinitrobenzene is formed by the direct nitration of nitrobenzene with fuming nitric acid, the product being poured into water and recrystallized from dilute alcohol.
The urea oxalate is recrystallized and decolorized and finally decomposed by calcium carbonate (J.
This is distilled to dryness and the distillate repeatedly recrystallized from cymene.