Solutions of Mg(NO3)2·6H2O, Al(NO3)3·9H2O, NaOH and Na2CO3 were mixed in a rotating liquid memb rane reactor. The crystal growth process of Mg Al CO3 hydrotalcite was then studied by adding different amounts...Solutions of Mg(NO3)2·6H2O, Al(NO3)3·9H2O, NaOH and Na2CO3 were mixed in a rotating liquid memb rane reactor. The crystal growth process of Mg Al CO3 hydrotalcite was then studied by adding different amounts of water to the resulting slurry during the crystallizing process. The initial 6 hours of the crystallization was found to be the key period controlling crystal growth. Adding 150 to 250mL of water to the reaction system at the beginning of crystallization affords Mg Al CO3 hydrotalcite with relatively small particle size and large aspect ratio.展开更多
The effect of supersaturation, oxalate/calcium stoichiometrical ratio (Oxa2-/Ca2+) and ionic strength on the crystallization of calcium oxalate (CaOxa) was investigated in gel systems by a double diffusion technique. ...The effect of supersaturation, oxalate/calcium stoichiometrical ratio (Oxa2-/Ca2+) and ionic strength on the crystallization of calcium oxalate (CaOxa) was investigated in gel systems by a double diffusion technique. The supersaturation affects the morphology, phase composition, and aggregation of CaOxa crystals. To a certain con- centration, the effect of Oxa2- ions on the aggregation of calcium oxalate monohydrate (COM) was much stronger than that of Ca2+ ions. It indicated that the increase of the concentration of Oxa2- ions can more efficiently pro- mote the formation of CaOxa stones. The increase of ionic strength and the molar ratio of Ca2+/ Oxa2- also pro- motes the aggregation of COM crystals.展开更多
文摘Solutions of Mg(NO3)2·6H2O, Al(NO3)3·9H2O, NaOH and Na2CO3 were mixed in a rotating liquid memb rane reactor. The crystal growth process of Mg Al CO3 hydrotalcite was then studied by adding different amounts of water to the resulting slurry during the crystallizing process. The initial 6 hours of the crystallization was found to be the key period controlling crystal growth. Adding 150 to 250mL of water to the reaction system at the beginning of crystallization affords Mg Al CO3 hydrotalcite with relatively small particle size and large aspect ratio.
文摘The effect of supersaturation, oxalate/calcium stoichiometrical ratio (Oxa2-/Ca2+) and ionic strength on the crystallization of calcium oxalate (CaOxa) was investigated in gel systems by a double diffusion technique. The supersaturation affects the morphology, phase composition, and aggregation of CaOxa crystals. To a certain con- centration, the effect of Oxa2- ions on the aggregation of calcium oxalate monohydrate (COM) was much stronger than that of Ca2+ ions. It indicated that the increase of the concentration of Oxa2- ions can more efficiently pro- mote the formation of CaOxa stones. The increase of ionic strength and the molar ratio of Ca2+/ Oxa2- also pro- motes the aggregation of COM crystals.
