Freeing waste material from heavy metals and dioxin(s) - by treating aq. slurry with active gas mixt. and precipitating heavy metals

摘要

In freeing liq., powder or slurried waste of agricultural, municipal or industrial origin from contamination with heavy metal salts, esp. sulphides, oxides or hydroxides, and dioxins, the waste, contg. heavy metals in insol. form, or dioxins, and ground to grain size below 100 microns, is slurried with leach water and the metal cpds. and dioxins are quasi-selectively disintegrated in 2 stages by means of an active gas mixt. with a reaction redox potential of at least -1 to 1.8 volts, and dissolved in the sludge, non-disintegrated solids are filtered off, and the resulting sec. soln. is treated in 2 stages with a pptg. agent to ppte. the heavy metals.