Abstract:
A method for solid-phase activation and neutralization of bauxite refinery residue (“red mud”) comprises the steps of preparing a quantity of untreated red mud having a moisture content of approximately 15 percent by weight, introducing a quantity of at least one reagent, and mixing in a mixer the quantity of untreated red mud and the quantity of at least one reagent. The mixing step is adapted to expose reaction sites at the nano-particle level. In one embodiment, the at least one reagent is calcium chloride and magnesium chloride salts. In another embodiment, an acid is introduced to the quantity of untreated red mud and the quantity of at least one reagent. A neutralized and activated red mud formed by the process is suitable for heavy metals remediation in soil and water.
Abstract:
A method for dehalogenation detoxication of halogenated aromatic and/or cyclic compounds, based on the fact that at least one halogenated aromatic and/or cyclic compound is heated on a support matrix in a closed system at a temperature of 200 to 500° C. in the presence of copper in metallic form and/or in the form of copper compounds, a hydrogen donor, carbon and at least one additional reducing substance, capable of reducing cupric and cuprous ions to elemental copper at the above temperature.
Abstract:
Chemical agents, such as chemical munitions, are decomposed by bringing them into contact with a plasma arc of a DC plasma arc furnace operated at a temperature of greater than about 30,000.degree. F.
Abstract:
There is disclosed an improved method and system for the selective treatment and volume reduction of mixtures of gaseous, liquid and solid contaminated waste materials. The contaminated waste materials include mixtures of hazardous and/or radioactive wastes which react with selected active reducing metals in liquid form, preferably aluminum.
Abstract:
The present invention relates to a method and an apparatus for injecting a particulate solid into a molten bath. The method includes forming a liquid stream and directing a first portion of the stream through an ejector for subsequent injection into a molten bath. A second portion of the liquid stream is directed into a receiving vessel. A particulate solid is directed into the receiving vessel, wherein the second portion of the liquid stream and the particulate solid combine to form a slurry. The slurry is directed from the receiving vessel to the ejector, whereby the slurry and the first portion of the liquid stream are combined to form a dilute slurry that is injected into the molten bath. The relative flow rates of the first and second liquid streams can be adjusted in direct relation to any change in the ratio of pressure of the two streams, controlling in this way the volume fraction of solids in the diluted slurry.
Abstract:
A method and apparatus for top-charging a solid waste into a molten metal bath to form a dissociation product are disclosed. The method includes introducing the waste into the molten metal bath through a refractory tube disposed in a reactor, containing the molten metal bath, through which the refractory tube extends. A gas outlet is disposed above the molten metal bath. The refractory tube has a submergible end which is immersed in the molten metal bath and which defines a lower opening at the terminal end of the refractory tube and an elevated opening, whereby a portion of the molten metal bath enters the refractory tube through the lower opening to allow the molten metal bath to remain within the refractory tube while at least partially dissociating the waste to form the dissociation product in the molten metal bath. An oxidizing agent can be directed into the molten metal bath at a rate sufficient to form an gaseous oxygenated product which is discharged from the reactor.
Abstract:
An industrial waste management facility (IWMF) for disposing of spent potlining includes a co-current gas-fired rotary kiln for containing a molten pool of spent potlining throughout the entire length of the rotary kiln from the inlet to the outlet, an ash quencher and cooler for receiving molten residue from the discharge end of the rotary kiln, a secondary combustion chamber, and a down-draft transition chamber for channeling discharge gases from the rotary kiln to the secondary combustion chamber. Pneumatic injection slingers feed and distribute spent potlining into the inlet end of the rotary kiln. A discharge dam provides a predetermined average depth of molten bath material in the rotary kiln over its entire length. A blended ratio of comminuted materials injected through the pneumatic injection slinger feeder is adjusted and controlled in response to signals received from a radiative optical kiln bath temperature measurement system. The IWMF recovers fluorides from discharge gases exiting the secondary combustion chamber, recycles the fluorides to the molten bath or pool of the rotary kiln, and collects and withdraws glass frit residue from the ash quencher and cooler.
Abstract:
For disposal of waste material including water, volatile components and vitrifiable components, the waste material is heated in a dehydrator to remove the water, heated in a high-temperature dryer to vaporize hydrocarbon liquids, and then fed to the focus point of a primary plasma reactor where plasma arc jets are focused on the surface of a pool of the vitrifiable components. At the focus point the vitrifiable components are melted, and the volatile components are volatized. The melted vitrifiable components are received in a quench chamber where they solidify on a quench roller and are broken into chips and delivered to a receiving area. Heat from the quench chamber is transferred to the dehydrator and high-temperature dryer. The hydrocarbon liquids and volatized components are fed to a secondary plasma reactor where they are disassociated into their elemental components. The effluent from the secondary plasma reactor is scrubbed to remove hydrogen sulfide and halogens, and residual components, together with excess water vapor, are extracted in an absorber and fed back for further processing in the secondary plasma reactor.
Abstract:
A molten salt process vessel for treatment of hazardous materials such as explosive or propellant waste, employing a tall, thin vessel with sufficient height that salt splash from the molten salt at the bottom of the vessel can be controlled and hard salt deposits are prevented from forming on the walls which restrict the gas outlet. The vessel, e.g. of cylindrical shape, has an increased height to diameter ratio in the range of about 7:1 to about 12:1, to give additional clearance. As an additional feature the vessel diameter can also be adjusted to create a "necked-down" region just below the gas outlet duct adjacent the top of the vessel to increase product gas velocity of the gas containing entrained salt particles, to prevent sticking of such particles to the vessel walls and restricting the gas outlet duct. A further feature of the invention is the provision of baffles located just above the body of molten salt in the region where temperature is at or above the salt melting point, inhibiting salt splash to the top of the vessel, and permitting molten salt particles striking the baffles to drain back to the body of molten salt.
Abstract:
A method of destroying organic waste in a bath of molten metal and slag contained in a vessel (3) is disclosed. The method comprises injecting organic waste into the bath to form a primary reaction zone (13) in which the organic waste is thermally cracked and the products of the thermal cracking which are not absorbed into the bath are released into the space above the surface of the bath. The method further comprises injecting an oxygen-containing gas toward the surface of the bath to form a secondary reaction zone (17) in the space above the surface of the bath in which the oxidizable materials in the products from the primary reaction zone (13) are completely oxidized and the heat released by such oxidation is transferred to the bath. In order to facilitate efficient heat transfer from the second reaction zone (13) to the bath, the method further comprises injecting an inert or other suitable gas into the bath to cause molten metal and slag to be ejected upwardly from the bath into the secondary reaction zone (17).