Exhausted granular organic ion exchange resins disposal for useful active carbon - by converting to carbon@ pellets by carbonising in mainly inert atmos. and activating in oxidising atmos. for cation exchange styrene] acrylic] acid resin

摘要

The disposal involves converting used, granular organic ion exchange resins (I) into active carbon pellets by carbonising at 300-900 deg.C in mainly inert atmos. and activating in an oxidising atmos. Pref. high strength active carbon pellets (II) are obtd. by the disposal. (I) are esp. cation exchange resins based on sulphonated styrene-DVB or styrene-acrylic acid copolymers, pref. in the H form, or anion exchange resins based on polystyrene or polyacrylic resins contg. tert. or quat. amino gps. (I) are pref. dried before carbonising. The atmos. used for carbonisation at up to 400 (up to 350) deg.C. contains 0.2-4 vol.% oxygen, esp. with (I) partly or completely replaced by granular, organic adsorber resin. Pref. for activation from 700 deg.C upwards, 3-50 (3-15) vol.% water vapour is added to the inert atmos., and CO2 may be added to the inert atmos. for carbonisation from 700 deg.C upwards. Activation is pref. in a separate stage, and both treatments are pref. in a fluidised bed or a rotating tubular furnace. Before reaching the softening pt., (I) is dusted with inert powder, pref. carbon powder. USE/ADVANTAGE - The exhausted (I) (i.e. blocked with suspended material, contaminated with microorganisms, inorganic ions, etc.) may be converted into useful active carbon instead of dumping.