Soln. crystallisation and filtration using large seed quantity

摘要

Method of crystallising and filtering material from soln. involves (a) introducing the soln. into a pptn. and filtration reactor; (b) stirring the soln. in the presence of 300-1000 (pref. 400-1000) g./l. crystallisation seeds of the material to ensure homogeneous dispersion of the seeds without producing fines by shear; and (c) filtering to recover a purified soln. Also claimed is a pptn. and filtration reactor for the above method, the reactor having (i) a filter cartridge (20) which divides the reactor interior into an internal pptn. chamber (12) and a recovery chamber (13) located between the cartridge and the reactor side wall; (ii) an inlet (11) for introducing soln. into the pptn. chamber; (iii) an outlet (14) for discharging treated soln. from the recovery chamber; and (iv) a mechanical stirrer (30) positioned in the pptn. chamber (12).