摘要:
A method for treating a nitric aqueous liquid effluent containing nitrates of metals or metalloids, comprising a step for calcination of the effluent in order to convert the nitrates of metals or metalloids into oxides of said metals or metalloids, at least one compound selected from the nitrates of metals or metalloids and the other compounds of the effluent leading upon calcination to a tacky oxide, and a dilution adjuvant leading upon calcination to a non-tacky oxide being added to the effluent prior to the calcination step, a method wherein the dilution adjuvant comprises aluminium nitrate and at least one nitrate selected from iron nitrate and rare earth nitrates.
摘要:
Disclosed herein is provided an evaporator/calciner in which hazardous materials, such as radioactive liquids, are converted into chemically stable, solid forms by evaporating, drying and calcination within a single vessel, that can then be sealed and used for long term storage.
摘要:
A method of reducing the volume of a mixture of filter fibers and a powder-form ion-exchange resin, produces a waste product that is particularly suitable for ultimate disposal. A solvent which dissolves the filter fibers is added to the mixture and a mixture which is thus formed is first dried and then given an additional heat treatment.
摘要:
A method of containing hazardous and toxic wastes includes the steps of irporating the dried waste, in a salt form, in melted polymer, such as asphalt, and forming the waste salt and asphalt blend into aggregate pellets. The pellets are coated with a powdered coating material that is compatible with a portland cement-based mortar or other cementitious material which is used. The coated particles are mixed with mortar to form a polymer-aggregate concrete and cast into wasteforms for storage or burial. If it is desirable to produce a waste form with a continuous layer of mortar on the exterior of the concrete monolith the mold can be placed on a turntable and spun, or otherwise exposed to a centrifugal force to force the mortar to the outside of the mold. Centrifugal separation is possible because the polymer-waste mixture typically has a specific gravity near 1.5 while that of the cementitious mixture is typically greater than 2.0.
摘要:
A method and apparatus are disclosed wherein toxic and nuclear waste are pumped in a metered fashion or introduced through a sealing door into a plasma region. The plasma region is generated in a sealed chamber by a radio frequency plasma torch. In the plasma region the toxic waste is atomized and ionized. The recombining of the atomized and ionized molecules is managed in the sealed reaction chamber to yield environmentally neutral products. Encapsulation material that is either introduced into the process chamber with the waste or is resident in the process chamber encapsulates radioactive or heavy metal atoms in a glassy stone like material. This encapsulating renders the atoms environmentally neutral. The flow of material in and out of the reaction chamber are regulated carefully. The radio frequency power level is also carefully controlled. These controls insure the neutrality of the recombining products. The fluids exiting the chamber are filtered before release, to insure environmental neutrality.
摘要:
A method of oxidatively decomposing a radioactive ion-exchange resin is described, the method comprising oxidatively decomposing a radioactive ion-exchange resin containing an anion-exchange resin with hydrogen peroxide used as an oxidizing agent in the presence of iron and copper ions used as catalysts, wherein the weight ratio of hydrogen peroxide to the ion-exchange resin, that is the ratio of the net weight of hydrogen peroxide to the dry weight of the ion-exchange resin containing an anion-exchange resin, is held to be no higher than 17 and the pH of the reaction system is adjusted to be within the range of 0.5 to 6, or citric acid ions are preliminarily adsorbed on the radioactive ion-exchange resin before it is subjected to decomposition treatment or citric acid ions coexist with the radioactive ion-exchange resin in the oxidatively decomposing system, and an apparatus used for conducting the method is also described.
摘要:
Wastes, in the form of liquids, solids and slurries, are converted to a mixture of a gas and an inorganic ash by introducing the waste as a finely atomized spray into a zone heated by means of a hot gas. Contact of the spray particles with the hot gas results in drying the waste and calcining and combusting the dried waste. The process is particularly useful with wastes containing hazardous materials such as radioactive substances.
摘要:
A method of immobilizing boric acid liquid wastes containing radionuclides by neutralizing the solution and evaporating the resulting precipitate to near dryness. The dry residue is then fused into a reduced volume, insoluble, inert, solid form containing substantially all the radionuclides.
摘要:
This invention is directed to a method and an apparatus to heat certain particles. These certain particles are heated to make them more desirable. In the heating of these particles, it is often desirable to expand the particles to make a light-weight aggregate. The light-weight aggregate may be used in making a building material or the like. In carrying out the process of heating these particles, there is used air for combustion of the combustible fuel and only a mimimum of air for carrying of the particles or expansion of the particles.
摘要:
Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means.