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US 5,859,306 AGranted
Method of treating arsenic-contaminated matter using aluminum compounds
AssigneeRMT, Inc.
InventorRobert R. Stanforth
Life of this patent
Estimating the term…
Abstract
A method of treating arsenic-contaminated matter using an aluminum compound in conjunction with an alkaline buffer, thereby stabilizing the arsenic contained in the contaminated matter and decreasing leaching ability. Preferably, the aluminum compound is a soluble aluminum salt such as aluminum sulfate and the alkaline buffer is magnesium oxide.
Claims10
A method for the treatment of arsenate-contaminated solids resulting in stabilization of said arsenate-contaminated solids against leaching of arsenic comprising:
- adding an aluminum compound selected from the group consisting of aluminum sulfate, aluminum chloride and sodium aluminate and an alkaline pH adjusting substance selected from the group consisting of calcium oxide, magnesium oxide, magnesium hydroxide, calcium carbonate and calcium magnesium carbonate to arsenic contaminated matter, wherein said aluminum compound comprises about 2.5% to about 15% by weight and said pH adjusting substance comprises about 2.5% to about 10% by weight, based on the weight of the arsenic matter;
- and
- mixing said aluminum compound, alkaline pH adjusting substance and arsenate contaminated solids to form a reaction mixture which has a pH level between pH 5 and pH 10 and precipitate a stabilized, non-leachable aluminum-arsenate complex the treated solids containing said aluminate arsenate complex, having an arsenic concentration below approximately 5 mgs per liter as determined by the TCLP test.
Dependencies are inferred from the claim text.