Composition to encapsulate chromium, arsenic and other toxic metals in wastes
AssigneeSafe-Waste Systems, Inc.
InventorCharles D. Falk
Life of this patent
Estimating the term…
Abstract
A composition for treating toxic metals in solid waste, sludge or slurry is provided. The composition includes a reducing agent such as ferrous sulfate or sodium sulfite and a fixative containing solid calcium oxide or solid magnesium oxide. The composition may also include an acid such as sulfuric acid.
Claims40
A composition for encapsulating toxic metals contained in a non-radioactive solid waste, sludge or slurry in which the toxic metals may exist or be capable of existing in a state having the tendency to leach into ground water comprising:
- a precipitating agent for the toxic metals comprising an aqueous silicate solution in an amount between about 0.05 and 5 weight percent, said silicate solution comprising between about 5 and 15 percent of an alkali metal oxide and between about 10 and 30 percent silicon dioxide;
- and
- a fixative comprising substantially solid magnesium oxide in an amount between about 5 and 100 weight percent;
- wherein the weight percents are based on the solid waste, sludge or slurry being treated.
A process for encapsulating toxic metals contained in a non-radioactive solid waste, sludge or slurry in which the toxic metals may exist or be capable of existing in a state having the tendency to leach into ground water, wherein said process comprises the steps of:
- mixing said solid waste, sludge or slurry with a precipitating agent for the toxic metals comprising an aqueous silicate solution in an amount between about 0.05 and 5 weight percent, said silicate solution comprising between about 5 and 15 percent alkali metal oxide and between about 10 and 30 percent silicon dioxide;
- and
- mixing said waste, sludge or slurry containing the aqueous silicate solution with a fixative material in an amount between about 5 and 100 weight percent, said fixative comprising substantially solid magnesium oxide;
- wherein said weight percents are based on the solid waste, sludge or slurry being treated.
A composition for encapsulating toxic metals contained in a non-radioactive solid waste, sludge or slurry in which the toxic metals may exist or be capable of existing in a state having the tendency to leach into ground water comprising:
- at least one of an anion adsorbent in an amount no greater than about 30 weight percent and reducing agent in an amount no greater than about 35 weight percent;
- and
- a fixative in an amount between about 5 and 150 weight percent, said fixative comprising a substantial portion of magnesium oxide;
- wherein the weight percents are based on the solid waste, sludge or slurry being treated.
A process for encapsulating toxic metals contained in a non-radioactive solid waste, sludge or slurry in which the toxic metals may exist or be capable of existing in a state having the tendency to leach into ground water, wherein said process comprises the steps of:
- mixing said waste with at least one of an anion adsorbent in an amount no greater than about 30 weight percent and a reducing agent in an amount no greater than about 35 weight percent;
- and
- mixing said waste, sludge or slurry containing at least one of the anion adsorbent and the reducing agent with a fixative material in an amount between about 5 and 150 weight percent, said fixative material comprising a substantial portion of magnesium oxide;
- wherein said weight percents are based on the solid waste, sludge or slurry being treated.
Dependencies are inferred from the claim text.