Process for treating metal-contaminated materials
AssigneePhysical Sciences, Inc.
InventorsSrivats Srinivasachar, Joseph Morency, Daniel C. Itse
Life of this patent
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Abstract
A process for treating wastes contaminated by toxic metals and/or organic materials is disclosed. The process involves heating the metal-contaminated wastes to a temperature sufficient to volatilize the metals. This temperature is also high enough to destroy or volatilize organic contaminants. The metal vapors are contacted with a sorbent which is reactive with the metals and sequesters them, thereby forming a non-leachable complex which can be disposed as non-hazardous conventional waste.
Claims35
A process for treating waste, soils or other material contaminated with mercury in order to render the mercury non-leachable, comprising:
- a. heating the waste, soils or other material to a temperature sufficient to volatilize the mercury and to form a gas stream having mercury vapor and ash particles entrained therein;
- b. providing in contact with the gas stream a carbonaceous material which adsorbs the mercury thereby removing it from the gas stream, and removing the carbonaceous material with the mercury adsorbed thereon from the gas stream;
- d. separating the carbonaceous material from the ash particles;
- and
- e. recovering the mercury by heating the mercury-laden carbonaceous material in the presence of a purge gas to a temperature sufficient to volatilize the mercury thereby forming a gas stream containing mercury Vapor and cooling the gas stream to a temperature sufficient to condense the mercury.
A process for treating wastes, soils or other materials contaminated with metals including mercury comprising:
- a. heating the waste, soils or other material to a temperature sufficient to volatilize the metals and the mercury thereby forming a gas stream having metal vapor, including mercury vapor, and ash particles entrained therein;
- b. cooling the gas stream sufficiently to cause condensation of the metal vapors onto the surface of the ash particles;
- c. providing in contact with the gas stream a carbonaceous sorbent comprising particles having a diameter of 100 microns or less which adsorb the mercury vapor thereby removing the mercury from the gas stream;
- d. removing the metal-coated ash particles and the carbonaceous sorbent with the mercury adsorbed thereon from the gas stream;
- and
- e. separating the ash particles from the carbonaceous sorbent using electrostatic separation, size classification or density separation methods.
A process for treating in situ waste, soils or other materials contaminated with mercury wherein said waste, soils or other materials comprise a carbonaceous sorbent reactive with mercury, the process comprising:
- heating the waste, soils or other material to a temperature sufficient to volatilize the mercury to mercury vapor, maintaining said heating for a time and at a temperature sufficient to induce said mercury vapor to adsorb to the carbonaceous sorbent, and removing the mercury-laden carbonaceous sorbent.
A process for treating waste, soils or other material contaminated with metals in order to render the metals non-leachable, comprising:
- a. combining the metal-contaminated waste, soils or other material with a sorbent which is chemically reactive with the metals thereby forming an intimate mixture thereof;
- b. heating the combination formed in step (a) to a temperature sufficient to render the metals reactive or to volatilize the metals thereby forming metal vapors;
- and
- c. maintaining the heating for a time sufficient to induce a chemical reaction between the reactive metals or metal vapors and the sorbent thereby forming a substantially non-leachable metal-sorbent complex.
Dependencies are inferred from the claim text.