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US 5,207,910 AGranted
Combined filtration and fixation of heavy metals
AssigneeenviroGuard, Inc.
InventorRoy S. Rieber
Life of this patent
Estimating the term…
Abstract
The present invention describes a filter medium and a method of filtering metals from liquids, such as waste water, in which the metals are filtered from the liquids and are chemically fixed in the resulting filter cake in a nonhazardous and nontoxic form so that they may be disposed of in nonhazardous landfills. When all or a portion of the metals are dissolved, they are first precipitated and then filtered and chemically fixed.
Claims5
A filter medium for filtering and chemically fixing metal precipitates in a waste liquid having a pH from about 8 to 14 comprising,
- a mixture of silicon particles and at least one polyvalent metal ion,
- the silicious particles being present in an amount effective to filter the metal precipitates from the liquid and to contain them,
- the silicious particles effective to form a soluble silicate with the liquid,
- the polyvalent metal ion being present in an amount when combined with any polyvalent metal ions in the waste liquid sufficient to form a silicious cement with the soluble silicate and to chemically fix the metal precipitates in the silicious cement.
1 more element
Dependencies are inferred from the claim text.