碳酸钙晶须的合成及形成过程

研究了用氯化钙－氯化镁－氢氧化镁体系碳化制备碳酸钙晶须的过程。结果表明，在较高的初始氧化钙与氯化镁摩尔比下，所得粉体由碳酸钙球形粒子，玉米棒状晶须和少量光滑晶须构成。在碳化过程, 首无形成大量的碳酸钙球形粒子，然后粒子集形成粒子链，继续生长或断裂形成玉米棒状结晶，光滑晶须在反应的后期形成。体系中反应前存在的氢氧化钙粒子是早期球形粒子聚集成粒子链，进而形成玉米棒状晶须的原因。在较低的氧化钙与氯化镁摩尔比下，晶须的形成过程不同于高氧化钙与氯化镁摩尔比下的情况，可以制轩出由大量光滑晶须和少量球形粒子构成的粉体材料。

Synthesis and formation process of calcium carbonate whiskers

The synthesis and formation process of calc iu m carbonate whiskers by the carbonation of CaCl 2-MgCl 2-Mg(OH) 2 system were investigated.The results indicate that the final product is composed of CaCO 3 spherical particles,corrn-shape whiskers and smooth whiskers under higher initi al CaO/MgCl 2 molar ratio.In the carbonation process,spherical CaCO 3 particle s were formed first,and then aligned to form chain-like CaCO 3,some of which co ntinued to grow or were broken to form the corrn-shape whiskers.The smooth whisk ers formed in the later stage of the carbonation process.And the Ca(OH) 2 parti cles present in the system before carbonation reaction is the direct cause for t he formation of the chain-like CaCO 3 particles.A product almost composed of sm ooth whiskers can be obtained under lower initial CaO/MgCl 2 molar ratio.