Cleaning phosphoric acid including recovery from the organic solvent by heating to stratify into an acid layer and an organic layer
Abstract
Abstract PROCESS WHICH COMPRISES EXTRACTING TECHNICAL GRADE PHOSPHORIC ACID WITH CERTAIN ORGANIC SOLVENT SELECTED FROM THE GROUP OF ESTERS, KETONES AND GLYCOL ETHERS, WHICH FULFILL THE CONDITIONS SET FORTH BELOW, A SMALL PROPORTION OF SULFURIC ACID BEING ADVANTAGEOUSLY ADMIXED WITH THE TECHNICAL GRADE PHOSPHORIC ACID PRIOR TO SAID EXTRACTION: (A) PRACTICALLY NOT TO EXTRACT H3PO4 FROM AN AQUEOUS PHOSPHORIC ACID WHOSE H3PO4 CONCENTRATION IS BELOW A THRESHOLD VALUE OF ABOUT 35% BY WEIGHT; (B) TO EXTRACT, FROM AN AQUEOUS PHOSPHORIC ACID OF A CONCENTRATION ABOVE THE AFORESAID THRESHOLD VALUE, A SUBSTANTIAL PROPORTION OF H3PO4 WHICH IS THE LARGER THE HIGHER THE H3PO4 CONCENTRATION OF THE AQUEOUS ACID; (C) TO POSSESS A TEMPERATURE-DEPENDENT CAPABILITY OF DISSOLVING PHOSPHORIC ACID, BEING SUBSTANTIALLY GREATER AT LOW TEMPERATURES THAN AT HIGH TEMPERATURES; SEPARATING AN H3PO4-CONTAINING SOLVENT EXTRACT FROM THE RESIDUAL TECHNICAL-GRADE PHOSPHORIC ACID, AND RECOVERING PURIFIED PHOSPHORIC ACID FROM SAID EXTRACT.
Inventors
- 👤 Avraham Matitiahu Baniel
- 👤 Ruth Blumberg
Bibliographic Details
Claims Analysis
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