Nanosized calcium carbonate particles were prepared with a continuous gas-liquid membrane contactor. The effects of Ca(OH)

2

concentration

CO

2

pressure and liquid flow velocity on the particles morphology

pressure drop and membrane fouling were studied. With rising Ca(OH)

2

concentrations

the average size of the particles increased. The effects of Ca(OH)

2

concentration and CO

2

pressure on particles were not apparent under the experimental conditions. When the Ca(OH)

2

concentration and liquid flow velocity were high

or the CO

2

pressure was low

the fouling on the membrane external surface at the contactor entrance was serious due to liquid leakage

whereas the fouling was slight at exit. The fouling on the membrane inner-surface at entrance was apparent due to adsorption of raw materials. The membrane can be recovered by washing with dilute hydrochloric acid and reused for at least 6 times without performance deterioration.