摘要 |
<p>Aqueous, hydrochloric solutions, which are produced in various processes, for example in the pickling of steel, and which as their main component contain dissolved FeCl2, have the iron removed together with the silica (SiO2) by the iron first being precipitated as Fe(OH)2 from the solutions preferably neutralised with scrap, the precipitate being oxidised in a DC electrolytic cell employing insoluble electrodes without a diaphragm, by the precipitate being allowed to ripen further with stirring, with the addition of a flocculant if required, and the oxidised oxide, together with the entrained silica, being separated by decanting and the precipitate optionally being treated in a filter press. <IMAGE></p> |