METHOD OF OBTAINING PURE PHOSPHORIC ACID Russian patent published in 2010 - IPC C01B25/234 B01D11/04 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining pure concentrated phosphoric acid which can be used in production of industrial, feed and food phosphates. The method of obtaining pure phosphoric acid involves purification with a liquid organic solvent, after purification with simultaneous concentration through direct contact of the purified acid with a gaseous heat carrier in froth bed conditions while blowing fluorine compounds and circulation through the purified acid and adsorption refining at 75 - 100°C. Blowing and adsorption refining are carried out simultaneously during concentration by dispersing an adsorbent into the stream of circulating purified acid with mass ratio adsorbent : acid equal to 1 : (50 - 100), with subsequent separation of spent adsorbent and the formed residue.

EFFECT: method reduces adsorbent consumption and specific energy consumption while maintaining high degree of purity of phosphoric acid from fluorine, iron and silicon compounds and sulphate ions.

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