Recovery of asbestos from waste dispersion contg. insoluble soap - by treatment with a heavy metal cpd. and alkali to yield aq. asbestos fibre dispersion contg. soluble soap

摘要

An aq. colloid asbestos dispersion is converted into a solid body by reaction with a heavy metal cpd. It involves treating waste solid material with dilute inorganic acid to solubilise the heavy metal which is washed away, and then converting the pptd. insoluble surfactant to a soluble form with inorganic alkali. The resultant dispersion of asbestos and soluble surfactant is recycled to the mains process stream of the initial operation. Pref. the initial dispersion contains the water-soluble salt of an insoluble fatty acid, and the heavy metal ion used for pptn. is Ca, Mg, Al and/or Zn. The waste may be treated with HCl and then with NaOH. Environmental pollution and health problems associated with the disposal of waste asbestos are avoided.