Abstract: A certain group of electrically conductive refractory materials presently known for use in high temperature applications as throat constructions, melter sidewalls, forehearth, stacks, port sills, hot face lining for slagging coal gasifiers, slag runners, and linings for nuclear waste encapsulation furnaces may be used as electrodes permitting joule heating at temperatures in excess of 1200 C. in excess of about 4400 hours even in the presence of transition group element(s). More specifically, the invention is an electrode for melting earthen materials, wherein the electrode is made from an electrically conductive refractory material, specifically at least one metal oxide wherein the metal is selected from the group consisting of chrome, ruthenium, rhodium, tin and combinations thereof.

Abstract: A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe.sub.3 O.sub.4. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe.sub.2 O.sub.3. Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater.

Abstract: There are provided a solidifying material used for radioactive waste which comprises a latent hydraulic material, an ultra-fine powder substance and a dispersing agent, and a process for the solidification of radioactive wastes which comprises kneading the above solidifying material with a cure stimulating agent, radioactive waste and, as occasion demands, water, and then curing the mixture by aging. Since the solidifying material of the present invention has excellent properties such as large treating capacity, excellent water resistance and large compressive strength, not only temporary storage but also permanent storage of radioactive wastes can be made.

Abstract: A method of treating a waste material, such as a radioactive waste material, by introducing the material into a high temperature reaction vessel such as an electric arc furnace. By controlling the reducing potential of the oxide phase formed in the reaction vessel, the concentration of the waste material in the oxide phase can be controlled. In addition, the morphology of the oxide phase can be controlled so that once the concentration of the waste material in the oxide phase is adjusted as desired, the waste material can be sequestered within the crystal lattice of the cooled oxide phase for subsequent disposal.

Abstract: A tank furnace for the inertization of non-flammable batch, which contains hazardous substances, metals and less than 10% by weight of carbon, by vitrification with glass forming aggregates by producing a glassy melt. The furnace has a batch charging device and a tank, on the rim of which a furnace crown rests, electrodes for heating the melt, a supply of oxidizing gases to the melt and, as an outlet for the melt, an overflow channel which can be heated. Nozzles are installed in the bottom of the tank to introduce oxidizing gases in order to reduce the eluate values, and the electrodes are immersed in the melt from above. It is preferable to install the nozzles at sloping sidewalls of the tank which slope upwardly and outwardly.

Abstract: A method for manufacturing filler materials for minerally bonded structural elements with thermal treatment of the starting materials to be used as filler materials involves subjecting comminuted high-polymer materials comprised of natural or synthetic origin materials to a shock-like heat radiation treatment by passing the materials under an irradiation unit to provide a temperature gradient of at least 20K per mm of travel distance of the materials beneath the irradiation unit in which an iron temperature of more than 600.degree. C. can be measured whereby the materials are inertized and are activated by heat in the range of a molar energy of 60 to 170 kJ*mol.sup.-1 and then placing the resulting activated materials in a crystal-forming solution of inorganic substances that enter into a permanently adhesive bond with a basic matrix of a composite material to be formed therefrom.

Abstract: An agglomeration process for metallurgical by-products and waste products is described, utilizing the sulphate material present in the metallurgical waste and by-products, which involves reacting the sulphate with water and optionally with an added alkaline earth metal compound. Sulphuric acid may also be added to the particles to be agglomerated. The obtained mixture is extruded or cast, and allowed to harden before being used in recycling to an extractive process. The agglomeration mechanism involves one or more of, hydration of a water soluble sulphate, precipitation of a water insoluble alkaline earth metal sulphate and hydration of a water insoluble sulphate.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which hazardous waste and any other necessary components for forming a glassy mixture upon heating are introduced for heating by a heater (38), and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. A voltage is applied across spaced electrical connections (72) of the melting vessel (46) to heat material within the melting vessel. Any failure of the melting vessel (12) is detected by a sensor (48). A stirrer (39) can be utilized to mix the material (18) during the heating. The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12).

Abstract: The invention relates to the conditioning or packaging of radioactive iodine, particularly iodine 129, using an apatite as the confinement matrix. Having the iodine, said apatite corresponds to the formula:M.sub.10 (XO.sub.4).sub.6-6x (PO.sub.4).sub.6x I.sub.2 (I)in which M represents Cd or Pb, X represents V or As, I is the radioactive iodine to be conditioned and x is such that 0.ltoreq.x<1. This iodoapatite (1) can be surrounded by an apatite (3) not containing iodine serving as a physical barrier.The iodoapatite can be obtained from a solid compound of the iodine, e.g. an iodide such as silver iodide or lead iodide, by reaction with a compound of formula:M.sub.3 (XO.sub.4).sub.2-2x (PO.sub.4).sub.2x (II)orM.sub.10 (XO.sub.4).sub.6-6x (PO.sub.4).sub.6x Y.sub.2 (III)in which M, X and x are as defined hereinbefore and Y can represent OH, F, Cl or O.sub.1/2.

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.

Abstract: An improved mixer for cementitious materials is described. This mixer is mobile and carried to the desired site and comprises a series of tanks and bins for containing the material to be mixed. The device is particularly useful in mixing hazardous wastes (e.g. low level radioactive soils, for example) within cementitious material along with sealants and chemicals designed to encapsulate the hazardous wastes therein. In order to thoroughly mix, and thus contain the hazardous wastes, the residence time within the mixing means must be between 4 and 45 seconds. This residence time may be achieved by keeping the mixing means within certain parameters of angles, relative to the ground, speed of mixing and length of mixing. By carefully controlling these variables, it is possible not only to achieve thorough mixing and encapsulation of the hazardous waste and to make a mobile mixing device that is extremely useful within the metes and bounds of the invention.

Abstract: A grouting material which is self-dispersing when brought into contact with a volume of water containing liquor or slurry and is settable to a solid mass after such dispersion, the material being in the form of self-dispersing granules or pellets and comprising a blend of component (A): a cementive constituent forming from 10 per cent to 95 per cent by weight of the composition; component (B): a dispersing constituent forming from 2 per cent to 75 per cent by weight of the composition; optional component (C): a swelling constituent which forms from 0 per cent to 50 per cent by weight of the composition; and component (D): a binder constituent which forms from 0.1 per cent to 10 per cent by weight of the composition; the percentages of components A, B, C and D adding to 100 per cent.

Abstract: A method of remediating soil contaminated with inorganic and organic pollutants as disclosed. A method comprises treating the soil with a complexing agent capable of chelating the pollutants and a matrix-generating agent for authigenically generating within the soil an alumino-silicate colloid matrix. The matrix has a plurality of reactive sites, which are capable of physically and chemically altering the pollutants into innocuous forms. The matrix-generating material comprises a mixture of a cement, blast furnace slag, fly ash, organophilic clay, and a free radical generator.

Abstract: The present invention generally relates to the formation of organic gels by dissolving organic gelling agents in organic solvents. The aryl cyclohexanol gelling agents employed in this invention are not structurally related to previously known gellation agents and they exhibit potent gellation activity, for example, from 0.2-5%, by weight, of gelling agent is able to immobilize a variety of organic solvents. The gels formed range from optically transparent to slightly translucent, and complete fluidity can be restored by either increasing the temperature (reversible) or by chemical treatment (irreversible).

Abstract: A method for solidification and stabilization of soils contaminated with vy metals and organic compounds removable by activated carbon includes the steps of placing a selected weight of the contaminated soil in a vessel, adding water to the contaminated soil in the vessel, mixing the soil and the water in the vessel, adding activated carbon to the mixture of soil and water in the vessel, mixing the soil, water and carbon in the vessel, adding cement and fly ash to the mixture of soil, water and carbon in the vessel, mixing the soil, water, carbon, cement and fly ash in the vessel and pouring the mixture of soil, water, carbon, cement and fly ash into a mold and curing the mixture therein.

Abstract: The present invention provides a method for encapsulating and stabilizing radioactive, hazardous and mixed wastes in a modified sulfur cement composition. The waste may be incinerator fly ash or bottom ash including radioactive contaminants, toxic metal salts and other wastes commonly found in refuse. The process may use glass fibers mixed into the composition to improve the tensile strength and a low concentration of anhydrous sodium sulfide to reduce toxic metal solubility. The present invention preferably includes a method for encapsulating radioactive, hazardous and mixed wastes by combining substantially anhydrous wastes, molten modified sulfur cement, preferably glass fibers, as well as anhydrous sodium sulfide or calcium hydroxide or sodium hydroxide in a heated double-planetary orbital mixer. The modified sulfur cement is preheated to about 135.degree..+-.5.degree. C., then the remaining substantially dry components are added and mixed to homogeneity.

Abstract: A method for cleaning contaminated surfaces or for cleaning bulk contamination of hydrocarbons or chemicals. To clean hydrocarbon or chemical contaminated surfaces, a basic aqueous silica solution is sprayed onto the contaminated surface and allowed to dry. The resulting dry material will flake off, leaving a cleaned surface, without damaging the surface. To clean bulk contamination of hydrocarbons or chemicals, the basic silica solution is mixed with hydrocarbons or chemicals and then an acidic aqueous polymer solution is added and mixed. An amorphous silica material is immediately formed which permanently encapsulates the hydrocarbons or chemicals and which dries to an inert powder.

Abstract: A safely encapsulated hazardous waste product free of unwanted leaching of contaminated metal constitutents and process therefor wherein a quantity of hazardous waste and a quantity of shale material characterized by having an aluminosilicate content containing at least 9.35% by weight of Fe.sub.2 O.sub.3, wherein the shale is reduced to a fine mesh before mixing, and defines a brick-like form as fired at about 1,150.degree. C. for a period of time to change the shale material into a semi-molten state and thereafter cooled to safely encapsulate the waste within the shale as a unit-handled product. The product of the invention satisfies and exceeds RCRA and LDR (EPA) requirements as shown by Toxicity Characteristic Leaching Procedure (TCLP) results.

Abstract: A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

Abstract: In this invention radioactive or hazardous containing materials are vitrified in a melter having two or more chambers. Glass feed materials are added to the primary chamber of the melter and they are heated to a molten glass which is then transported to one or more secondary chambers where hazardous and/or radioactive containing materials are added and are encapsulated and/or melted. In addition, the non-plutonium part of a glass feed can be melted in a non-radioactive environment which permits contact operations and maintenance; no radioactive shielding; and a conventional off gas system-similar to commercial vitrification plants. The hot molten "clean" glass is directed into a radioactive containment such as a "glove box"; shielded "glove box"; or hot cell, or a combination of these. By delivering hot "clean" glass from a melter including non-radioactive materials, 90% of the off gases will be non-radioactive.

Abstract: A process in which a calcining step is used to provide a stable clinker containing the EAF dust. The clinker meets all of the applicable leaching standards. It also appears to be possible to use largely oxidic wastes from other processes, such as zinc electroplating residues, and the largely oxidic residues from refuse fuelled power generators. In this low temperature vitrification process a powder composition containing from 20% to 63% by weight waste material, from 30% to 73% by weight silica, and from 7% to 30% by weight alumina, is wetted to form a homogenous mass. The mass is fired in a furnace for a sufficient time and to a temperature of less than about 1,300.degree. C. to cause vitrification; and the vitrified product is recovered as a fired clinker. The clinker, after crushing, can be used as a road aggregate, in tarmac mixes, or after crushing to a suitably small powder, in the making of bricks and tiles having good abrasion and heat resistance.

Abstract: A process for stabilizing organics-containing waste materials and recovering metals therefrom, and a waste glass product made according to the process. Vitrification of wastes such as organic ion exchange resins, electronic components and the like can be accomplished by mixing at least one transition metal oxide with the wastes, and, if needed, glass formers to compensate for a shortage of silicates or other glass formers in the wastes. The transition metal oxide increases the rate of oxidation of organic materials in the wastes to improve the composition of the glass-forming mixture: at low temperatures, the oxide catalyzes oxidation of a portion of the organics in the waste; at higher temperatures, the oxide dissolves and the resulting oxygen ions oxidize more of the organics; and at vitrification temperatures, the metal ions conduct oxygen into the melt to oxidize the remaining organics.

Abstract: Self-repairing, fiber reinforced matrix materials include a matrix material including inorganic as well as organic matrices. Disposed within the matrix are hollow fibers having a selectively releasable modifying agent contained therein. The hollow fibers may be inorganic or organic and of any desired length, wall thickness or cross-sectional configuration. The modifying agent is selected from materials capable of beneficially modifying the matrix fiber composite after curing. The modifying agents are selectively released into the surrounding matrix in use in response to a predetermined stimulus be it internal or externally applied. The hollow fibers may be closed off or even coated to provide a way to keep the modifying agent in the fibers until the appropriate time for selective release occurs.

Abstract: Disclosed is a method for converting spent nuclear fuel and surplus plutonium into a vitreous ceramic final waste form wherein spent nuclear fuel is bound in a crystalline matrix which is in turn bound within glass.

Abstract: Methods for waste treatment and compositions of stabilized waste elements are provided, typically for the disposal of arsenical wastes. Arsenic trioxide waste produced as a by-product of metal extraction is slurried in water for from 6 to 24 hours with finely divided quicklime to produce nonvolatile calcium arsenate (III). An excess of CaO stoichiometry with As is used to consume secondary waste species such as sulphate, silicate and iron oxides. The precipitated arsenate is oven dried at 120.degree. C. and then calcined in air between 15 minutes to several hours at 1000.degree. C. to 500.degree. C. respectively to oxidize arsenate (III) to arsenate (V) as Ca.sub.5 (AsO.sub.4).sub.3 (OH) (an apatite) as the major arsenic immobilization phase, with minor arsenic incorporated in Ca.sub.3 (AsO.sub.4).sub.2. Calcium sulphate anhydrate (sulphate immobilization) and calcium iron oxide (iron immobilization) are also produced.

Abstract: The present invention is directed to the art of treating waste using laser technology. Industrial and toxic waste materials are irradiated with a laser inside a reactor chamber such that they are heated to high temperatures. Organic compounds are thermally destroyed and chemical bonds are broken. Cool oxygen is pumped into the reactor to provide a refractory protective shield. Silica is added into the vessel at the high temperatures and encapsulates any heavy metals into its crystal matrix. The resulting solidified product may have a hardness of at least 8 on the Knoops scale of hardness and may be used as tooling, road material, oven lining, building materials and the like.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which a stirrer (38) mixes hazardous waste and any other necessary components for forming a glassy mixture upon heating while an electrical current is applied across the melting vessel and the stirrer to provide electrical current flow, and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12). The sensing of the failure can be either by a pressure change in the hermetically sealed chamber (58) or by sensing of the presence of material received by the containment vessel (46) from the failed melting vessel (12) such as by an electrical circuit type detection.

Abstract: A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH).sub.4 to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set.

Abstract: A process for an article of encapsulated waste which is acceptable for transportation and storage is prepared by whereby the contaminated solid is contacted in a bath of a molten paraffinic hydrocarbon encapsulating material for time sufficient to expel moisture and to coat the solid rendering the contaminant immobile, isolated and unleachable into the environmental system once the paraffin has solidified. An embodiment of this invention employs a zeolite to absorb liquid wastes expelled from the solid which remains in the article.

Abstract: This invention provides a process wherein hazardous or radioactive wastes in the form of liquids, slurries, or finely divided solids are mixed with finely divided glassformers (silica, alumina, soda, etc.) and injected directly into the plume of a non-transferred arc plasma torch. The extremely high temperatures and heat transfer rates makes it possible to convert the waste-glassformer mixture into a fully vitrified molten glass product in a matter of milliseconds. The molten product may then be collected in a crucible for casting into final wasteform geometry, quenching in water, or further holding time to improve homogeneity and eliminate bubbles.

Abstract: A process is disclosed for disposing mineral processing tailings. The process includes the step of treating the tailings to produce a flowable paste including a mass comprised of particles at least approximately 15% of which are less than 20 microns in diameter. The process further includes the step of preparing an unconfined ground surface tailings disposal site by grading a selected site to produce a substantially level paste receiving bed. The flowable paste is then deposited onto the paste receiving bed from a discharge station to flow by gravity to a natural angle of rest of between approximately 1.degree. and 10.degree. slope. The paste is allowed to consolidate from flowable to a solidified state, retaining the natural angle of rest. Overburden is then placed over the solidified paste. The process is particularly useful in ore processing using cyanidation in which cyanide destroying chemicals are used at or prior to preparation of the flowable paste.

Abstract: In this process for the treatment of waste products, the waste products are separated in a first and a second group with respective pH-value of maximum 7 or higher than 7. The waste products of the first group are made increasingly acid whereas those of the second group are basified. This is done by adding an acid to the first group and a base to the second group in order to obtain a pH-value of maximum 5 for the first group and a pH-value of minimum 8 for the second group. An oxidant and metallic precipitating reagents are added to the first group of waste products. The thus treated waste products are combined in an alkaline mixture that is absorbed in a polymeric matrix by adding reaction components for the formation of a polymeric matrix.

Abstract: A method for solidifying industrial waste containing various toxic metals and other substances without fail and stabilizing the waste so as to prevent the toxic metals, particularly lead, from leaching out. The method comprises mixing a waste containing calcium compounds such as hydroxide, oxide and chloride of calcium with a treatment mainly comprising water glass, adding, if necessary, water hereto to adjust the total water content to 25-75 parts by weight per 100 parts by weight of the waste, kneading the resultant mixture, and aging the same for at least 6 hours in a temperature range of 40.degree. to 100.degree. C., preferably by utilizing the waste heat of a waste incinerator.

Abstract: A process and apparatus for treating sewage sludge having the steps of providing sludge at a desired rate, mixing the sludge with at least one alkaline additive at a proportionate rate to the sludge to raise the pH of the mixture to at least a desired level, providing a pasteurization chamber having a means to heat the contents of the chamber, continuously delivering the sludge and alkaline additive mixture to the inlet opening of the pasteurization chamber, heating the pasteurization chamber to maintain a minimum temperature of the sludge and alkaline additive mixture in the pasteurization chamber, continuously conveying the sludge and alkaline additive mixture without any substantial agitation of the mixture for a desired duration through the pasteurization chamber such that the thixotropic mixture does not become watery, and continuously discharging the sludge and alkaline additive mixture from the discharge opening of the pasteurization chamber, whereby harmful pathogens are destroyed in the sludge.

Abstract: The present invention is directed to the use of water-soluble compositions containing a compound having a Lewis base group attached to a hydrophobic group where the Lewis base group is capable of donating at least one lone pair of electrons to a metal. These compositions are effective in treating acid mine drainage by treating the source of the acid mine drainage as well as the acid mine drainage waters. These compositions are also effective in removing metal and non-metal ions from aqueous sources and the process can be modified to allow the selective removal of metal and non-metal ions from aqueous sources.

Abstract: A process for preparing radioactive and other hazardous liquid wastes for treatment by the method of vitrification or melting is provided for.

Abstract: A system for the treatment of waste material includes a waste-receiving module for receiving waste material and blending it with glassmaking additives. The waste-receiving module is enclosed within a waste-receiving module container which is capable of being sealed for over the road transport so that the waste-receiving module can be transported safely from one source of waste material to another without complete decontamination. The system also includes a melter module containing a melter for melting together the blended waste material and glassmaking additives to form homogeneous molten glass and thereby stabilize the waste material. The molten glass is discharged to form a vitrified waste material. The melter module is comprised of one or more melter module containers which are capable of being sealed for over the road transport so that the melter module can be transported safely from one source of waste material to another without complete decontamination.

Abstract: A waste-treating material which comprises cement and at least one reducing metal, effective for stabilizing industrial wastes containing harmful metals like a heavy metal and the like and cyanides. A preferred example of the reducing metal is iron. Additionally the waste-treating material may also contain at least one member selected from a group consisting of a reducing agent, aluminum sulfate, allophane, and bentonite as the auxiliary. The use of this waste-treating material makes it possible to stabilize the hazardous heavy material and the cyanides contained in the industrial wastes, thereby remarkably contributing to a stabilizing treatment of the industrial wastes.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which hazardous waste and any other necessary components for forming a glassy mixture upon heating are introduced for heating by a heater (38), and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). Different embodiments of the heater (38) provide current flow through molten material (18) being heated, induction heating and electric resistance heating. A stirrer (39) can be utilized to mix the material (18) during the heating. The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12).

Abstract: A low-temperature method for producing coated hazardous waste pellets which re used as the aggregate in a concrete wasteform is characterized by combining hazardous waste with a chemically setting organic polymer to form a mixture which is formed into pellets. The pellets are first coated with epoxy and then coated with a silicate-based powder. The liquid concrete-pellet mixture is then placed in molds which can be rotated to concentrate the pellets away from the perimeter of the wasteform. The double-coated hazardous waste pellets have improved bonding when used as a coarse aggregate in a concrete mixture. The resulting wasteform is self-supporting and needs no external container for transportation, storage, or disposal.

Abstract: An apparatus and method provides a way of collecting, treating, processing and recycling a variety of hazardous waste material and transforming such materials into a stable, granular nonhazardous substance suitable for safe disposal. The apparatus disclosed combines a variety of separate mechanisms and devices such as vibrating screens, motorized crushers, conveyor systems, and electric or fuel powered motors into a single integrated machine. Chemical additives can be used to treat the waste and bond to any heavy, leachable materials such as lead, copper, cadmium, zinc and other metals and thus lower their leaching characteristics to acceptable nonhazardous levels in compliance with Environmental Protection Agency standards. A concrete additive is added to the waste and the mixture is ground into a manageable substance of uniform texture and consistency.

Abstract: The method for rendering solid waste inert and for its subsequent definitive storage and a plant which allows this to be done, provide an initial stage in which the waste is reduced and/or prepared so that it can be covered then enveloped in substances which can form a coating on it; a second stage involving the mixing of waste prepared in the afore-mentioned manner with a bitumen-based substance; a third stage for the depositing and/or spreading of the amalgam obtained during the mixing stage directly below or above the ground; a fourth stage for compacting the amalgam so that the bitumen-based product solidifies, completely sealing in the waste and increasing its impermeability, thus preventing any contact between the waste and the surrounding environment.

Abstract: The present invention provides a method of disposing of hazardous particulate waste containing hazardous waste by forming an asphalt emulsion slurry and using the slurry as a commercial asphalt emulsion slurry seal. The method comprises the steps of:a) selecting an emulsifying agent suitable to form a stable emulsion of asphalt, water and said particulate waste;b) mixing the particulate waste and asphaltic emulsion in proportions to form an asphaltic emulsion slurry having safe leaching properties;c) utilizing said asphaltic emulsion slurry in existing commercial uses.

Abstract: Water-containing inorganic waste materials, originally in loose form, and which contain water-soluble components capable of reacting with each other are mixed and then compacted at a pressure sufficient to reduce the space, volume between the particles of material, cause the reduced space volume to become filled with water and the reactive components to react.

Abstract: A process for treating a contaminated solid unacceptable for disposal in the environment is described whereby the contaminated solid is contacted in a bath of a molten paraffinic hydrocarbon for time sufficient to expel moisture and to coat the solid rendering the contaminant immobile, isolated and unleachable into the environmental system once the paraffin has solidified. An embodiment of this invention employs a zeolite to absorb liquid wastes expelled from the solid.

Abstract: A buffering agent for a cementitious hazardous waste composition, containing electric arc furnace dust (EAFD) and water, includes dolomitic lime, namely either dolomitic quicklime, dolomitic monohydrated lime or dolomitic dihydrated lime. Dolomitic lime serves as a buffering agent for the hazardous waste composition by maintaining the pH of the waste composition within a target range over which solubility of several heavy metals tends to be minimized. These heavy metals include lead, zinc and cadmium, among others, and the pH range within which the heavy metals experience a minimum solubility is approximately 8.5 to 11.5, and preferably 9.4 to 10.2. In addition, dolomitic lime is substantially insoluble in water, so that the buffering agent will not leach or diffuse out of the waste composition.

Abstract: A method of immobilizing toxic waste material slurries is disclosed wherein aggregates are formed containing the toxic waste and the aggregates admixed with and embedded in a sulfur cement to form a concrete shape.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which a stirrer (38) mixes hazardous waste and any other necessary components for forming a glassy mixture upon heating while an electrical current is applied across the melting vessel and the stirrer to provide electrical current flow, and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). The containment vessel (46) is hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12). The sensing of the failure can be either by a pressure change in the hermetically sealed chamber (58) or by sensing of the presence of material received by the containment vessel (46) from the failed melting vessel (12) such as by an electrical circuit type detection.

Abstract: Sludges and slurries, e.g., oil, grease or paint based, are encapsulated into fly ash or similar particulate material by adding solvents to effect the encapsulation and absorption of the sludge. Subsequently, the particulate material is heated to remove the solvent, leaving a dry powder which may then be used as a filler for various applications, including production of breeze blocks.

Abstract: The process or the present invention serves to remediate and reduce the volume of waste materials in a landfill site and increases the useful life of the treated landfill. The process steps involve drilling a series of holes into the waste material mass at proper spacing, inserting and operating a plasma arc torch in each drilled hole to pyrolize, remediate and vitrify the waste materials and allowing the melted materials to cool and harden. During the process, a gaseous by-product is produced and collected in a hood which is attached to scrubbing and chemical cleaning apparatus. The resultant gases are commercially useful as fuel gas and the vitrified residue is significantly smaller in volume than the original waste material volume, thus substantially extending the useful life of the landfill site and ultimately providing a firm foundation for construction.