To efficiently adsorb and remove fluorine so that fluorine does not accumulate in liquid when using zinc-containing matters such as crude zinc oxide containing fluorine in a wet zinc smelting process.
The problem can be solved by making fluorine ions and ferric ions to co-exist in a sulfuric acid solution, neutralized the solution to produce iron precipitate and removing the fluorine through adsorption to and coprecipitation with the iron precipitate. In order to make the most of the capacity of elemental iron as a fluorine adsorbent, the fluorine-adsorbing iron precipitate is redissolved and used as an iron raw material for adsorbing fluorine for a plurality of times. By utilizing undissolved residues produced in the zinc smelting process as an iron raw material serving as an adsorbent and using fluorine-containing crude zinc oxide etc. as a neutralizer, the purpose can be accomplished through only the operations generally conducted in the wet zinc smelting process, i.e. dissolving, neutralization and solid-liquid separation, without requiring a large capital investment.
NISHINA KAZUHIKO
SAKATA MASATAMI
Next Patent: HEAT RESISTANT MEMBER