| 摘要 |
The invention relates to a process for preparing coagulation agents to be used in the purification of waste water. According to the invention, the process consists in that a mixture of black slag and ashes resulting from secondary Al waste melting is subjected to successive stages of washing with counterflow water, while recycling the washing water for 30 min/stage, a grinding operation taking place during the last washing stage, wherefrom a sodium chloride and potassium chloride solution is separated by filtration, as well as an Al slag fraction which is subjected to a two stage-solubilization of aluminium in HCl with aluminium chloride formation, after which the temperature of the aluminium chloride suspension is gradually increased for 6...8 h, up to the formation of aluminium polyhydroxychloride which is maintained at the temperature of 30°C for 16...20 h, for ageing, after which the salt is subjected to drying down to a humidity of 2%, the resulting product being rendered inert in a hydraulic binder matrix in a ratio of 60...90:10...40. |
