摘要:
The invention relates to a method for treating an asbestos solid (1), said method comprising at least one hot acid treatment step (4) for treating the asbestos (3) of the asbestos solid (1) at atmospheric pressure with an aqueous solution (5) of hydrochloric acid at a temperature close to the boiling temperature of the aqueous solution (5) of hydrochloric acid, in such a way as to obtain a so-called non-silicic solution (8) of at least one non-silicic constituent of the asbestos (3) in the aqueous solution (5) of hydrochloric acid and a so-called silicic solid (9). Said method is characterised in that the non-silicic solution (8) is subjected to a so-called precipitation treatment (13), wherein a selective precipitation (13) of the cationic species of iron present in said non-silicic solution (8) is carried out.
摘要:
The invention provides a method and device for decomposing environmental pollutants, capable of decomposing organic halogen compounds, etc., which are environmental pollutants in a short time and in large quantities to such a low concentration degree that allows them to be discharged as drainage into a sewage pipe or the like and also capable of decomposing organic substances, nitrogen, phosphorous, etc., which are hard to oxidation-decompose. To a sample solution (20) in a reaction vessel (10a) storing an aqueous solution containing environmental pollutants, a vibrator (30a) placed on the central bottom of the reaction vessel (10a), for example, radiates ultrasonic waves (50), and at the same time, ultraviolet lamps (40a) disposed on the peripheral edge within the reaction vessel (10a) radiate ultraviolet rays. On this occasion, the ultraviolet lamps (40a) are disposed at positions where they substantially do not interfere with the path of travel of ultrasonic waves (50).
摘要:
A composition for transforming a chrysotile asbestos-containing material into a non-asbestos material is disclosed, wherein the composition comprises water, at least about 30 % by weight of an inorganic acid, and from about 0.1 to about 4 % by weight of a tetrafluoroborate of ammonia, an alkali metal or an alkaline earth metal. A method of transforming the asbestos-containing material into a non-asbestos material using the present composition is also disclosed.
摘要:
A method of decomposing and removing dioxins from fly ash at a lower temperature in a short time, which comprises contacting the dioxins or the substance containing the dioxins with an amine compound and/or an ammonium compound at a temperature below 300 DEG C. Since the chlorine in the dioxins reacts with the amine compound and/or ammonium compound, the dechlorination of the dioxins proceeds rapidly at a lower temperature. Thus, dioxins can be decomposed and removed in a short time at a low temperature at which dioxins have not been thought to be decomposable.
摘要:
Chemical warfare agents are destroyed when chemically reacted with nitrogenous base, optionally containing solvated electrons which are conveniently produced by dissolving an active metal like sodium in a nitrogenous base such as anhydrous liquid ammonia. A reactor system (10) used to carry out the process comprises reaction vessel (20) adapted to receive either nitrogenous base or a solution of solvated electrons from solvator (30) and CWA from storage vessel (40). The reactor system also incorporates condenser (50) for treating gas evolved from the reaction vessel (20), decanter (60) for receiving slurried reaction products from the reaction vessel and separate the reaction products into a liquid fraction and a solid fraction, dissolver (70) for contacting the solid fraction with water to produce a fluid mixture and oxidizer (80) for oxidizing the fluid mixture.
摘要:
Soil including sand and clays contaminated with nuclear waste materials and/or ions of hazardous non-radioactive metals or metalloids are decontaminated by treating with anhydrous liquid ammonia alone or in combination with solvated electrons. Methods include removing ions of hazardous metals or metalloids by mixing with ammoniacal solutions to provide an ammoniacal liquid-containing product with coordination complexes. Methods also comprise concentrating contaminants, such as plutonium, uranium and thorium, for example, in the fines of soil and clay to yield residual soil products which are sufficiently free of contaminants to allow reclamation. Economics are improved over aqueous systems since ammonia canbe recovered and recycled. By concentrating nuclear and non-nuclear wastes in soil fines space requirements ordinarily needed for storage of untreated soil and handling costs can be significantly reduced.
摘要:
Ozone depleting fluorocarbon compounds (18) are dehalogenated through more economic reduction reaction with solvated electrons formed from lower equivalents of reactive metals (14) than previously used by reacting the partial reduction products with nitrogen-containing bases, such as ammonia (12) or alternatively, without any reactive metal by reacting with the base alone. Mixtures of fluorocarbon refrigerants including difficult-to-separate azeotropes of dichlorodifluoromethane contaminated with clorodifluoromethane are reclaimed by treating only with weak non-aqueous nitrogen-containing bases to provide essentially chemically pure dichlorodifluoromethanerefrigerant suitable for recycling/reuse. Hazardous cyanides which may develop are converted to relatively benign products during the process by introducing a base (22) to convert volatile cyanides to more stable salts which in turn are converted to useful compounds of lesser toxicity.
摘要:
Ozone depleting fluorocarbon compounds are dehalogenated through more economic partial reduction reactions with solvated electrons formed from lower equivalents of reactive metals than previously employed. The partially reduced products are further dehalogenated with non-aqueous liquid nitrogen-containing bases, such as ammonia in the same reaction mixture, or alternatively, in an independent reaction by treating with ammonia or other base alone. In other embodiments, mixtures of fluorocarbon refrigerants including difficult to separate azeotropes of dichlorodifluoromethane contaminated with chlorodifluoromethane are reclaimed by treating only with weak non-aqueous nitrogen-containing bases to provide essentially chemically pure dichlorodifluoromethane refrigerant suitable for recycling/reuse.
摘要:
A method of decomposing halogenated aromatic compounds safely without fail, which comprises bringing a solution of a halogenated aromatic compound in a hot-alkali-resistant polar solvent into contact with an alkaline substance at about 100 to about 300 DEG C to decompose the aromatic compound and removing the salt and alkaline substance precipitated in the solvent to recycle the used solvent.