Process for the precipitation of phosphate with iron hydroxide
AssigneeIndustrie Automation Sondertechnik GmbH & Co.
InventorsGerman Muller, Siegfried Riethmayer
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Abstract
A process is provided for the precipitation of phosphates from phosphate-comprising waters which utilizes iron hydroxide of the formula Fe.sub.2 O.sub.3.nH.sub.2 O wherein n=0.5-3.0. The iron hydroxide is prepared from natural or technical muds comprising iron in a process which involves dissolving with mineral acid and precipitation with a base. Other metal hydroxides are used together with the iron hydroxide.
Claims18
A process for the precipitation of phosphates from municipal and industrial waters and other phosphate comprising waters which comprises adding to the water a precipitating agent comprises of iron hydroxide of the formula
- Fe.sub.2 O.sub.3.nH.sub.2 O
- wherein n=0.5-3.0, and other metal hydroxides, said iron hydroxide being prepared by dissolving metals from iron comprising starting materials by means of mineral acids at pH 0.5-2.5, isolating undissolved solids from the dissolved metal salts and re-precipitating the iron as hydroxide at pH 3.5-4.5.
A method for the precipitation of phosphates from municipal and industrial waters and other phosphate comprising water, which comprises using as a precipitating agent an iron hydroxide of the formula
- Fe.sub.2 O.sub.3.nH.sub.2 O
- wherein n=0.5-3.0, and other metal hydroxides, said iron hydroxide being prepared by dissolving metals from iron comprising starting material by means of mineral acids at pH 0.5-2.5, isolating undissolved solids from the dissolved metal salts and re-precipitating the iron as hydroxide at pH 3.5-4.5.
Dependencies are inferred from the claim text.