| 摘要 |
Asbestos fibers, especially chrysotile mineral fibers, are decomposed and eliminated by being reacted with an acid component, e.g. sulphuric acid. The reaction is carried out at a pH of less than 5 for a period of time (e.g. up to several weeks or months) which is sufficient to obtain a substantially total decomposition of the fibers. The reaction may be speeded up by being subjected to heating, e.g. of a temperature in the range of 5-100 DEG C, and/or by a physical treatment. The decomposition may be carried out continuously or in batch. Also, the asbestos fibers may be decomposed by reaction with an aqueous solution of ammonium sulfate at a temperature of above 200 DEG C, preferably about 260 DEG C. The ammonium sulfate reaction is carried out in an autoclave, e.g. in the form of a pipe reactor or tubular reactor, in which the suspension of asbestos fibers and ammonium sulfate is subjected to a turbulent flow, i.e. having a Reynolds number of above 2000, and the reaction is generally terminated within 30 minutes. The magnesium which is released from the asbestos material during the treatment may be recovered. |
