Apparatus for purifying suspensions of water-insoluble particles

摘要

Apparatus for de-salting aluminium hydroxide particles or lakes based thereon comprises a reservoir 1 connected in recirculating fluid communication with a membrane ultrafiltration unit 2 via lines 4A,5A. A pump 3 is located between the reservoir and filtration unit, and an inlet 4 for make up water is located between the reservoir and pump. An injection device 6 maintains the water inlet rate within 20% of the hourly volume discharge rate of permeate at outlet 5 and is controlled by a suitable monitoring/feedback device eg a flow or level meter. The recirculating liquid may be monitored, eg by conductivity meter or spectrometer, to allow product recovery when a predetermined purity is achieved