Carlo Adamoli
Process for the extration of bases of rare elements contained in ores and rocks

Pagina 14

[Indice]

6. In a cyclic process for obtaining zirconium hydrate from silicated minerals containing a relatively small proportion of zirconium, the steps consisting of crushing the mineral, mixing it in a paste with magnesium fluoride and an aqueous solution containing hydrochloric acid and a water soluble alkali-metal chloride, heating said paste at a low temperature to form magnesium chloride, expelling from the paste the liquid containing the magnesium chloride and alkali-metal chloride, briquetting the paste and heating it to a high temperature to form a water soluble fluorine compound of zirconium, lixiviating the reaction product, separating therefrom a solution containing the fluorine compound of zirconium and at least a part of the initial alkali-metal chloride, electrolyzing said solution to precipitate zirconium hydrate, separating said precipitate,. mixing the solution from the electrolyzer and which contains fluorinated and chlorinated alkali-metal salts with the solution containing 7 magnesium chloride and alkali-metal chloride expelled from said paste to precipitate magnesium fluoride and form a solution of alkali-metal chloride, using a portion of said alkali-metal chloride solution in the electrolyzer for a fresh operation of precipitating zirconium hydroxide, converting the chlorine from the electrolyzer into hydrochloric acid, and returning to the cycle the precipitated magnesium fluoride, the hydrochloric acid and the alkali-metal chloride solution not used in the electrolyzer.

[Pagina Precedente] - [Indice] - [Pagina Successiva]