| 摘要 |
A method for purifying hydrofluoric acid, comprising the steps of filtering the hydrofluoric acid to remove particulates, passing the filtered acid through a cation exchange material and an anion exchange material to remove ions therefrom, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the cation exchange material for a predetermined level of cationic impurity representative of actual or impending ionic breakthrough in the cation exchange material, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the anion exchange material for a predetermined level of anionic impurity representative of ionic breakthrough in the anion exchange material, automatically interrupting flow of acid through the anionic or cationic exchange material at or prior to the time the breakthrough in such material occurs, while the flow is interrupted, regenerating the anionic or cationic exchange material, resuming the flow after the exchange material is regenerated, passing the acid from the cationic and anionic exchange materials through an ultrafilter and into a storage container, and monitoring the level of particulate impurities in acid that has passed through the anion and cation exchange materials and automatically passing the acid in the storage container through a filter when the level of particulates exceeds a predetermined level, until the particulates are below the predetermined level. Also disclosed is an apparatus for performing the foregoing process.
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