牡蛎煅制过程中的微观结构及CaCO3含量分析

Analysis of Microstructure and CaCO3 Content of Ostreae Concha in Calcining Process

目的：研究煅制牡蛎的微观结构变化,考察温度和时间对煅牡蛎质量的影响。方法：采用热重/差示扫描量热法（TG/DSC）分析牡蛎生品。取净牡蛎置于瓷坩埚中,在不同温度条件下,采用烘箱对样品进行煅制,每隔不同时间取出牡蛎,研磨后过200目筛备用。采用扫描电子显微镜（SEM）对煅制后的牡蛎表面进行分析。以BET氮气吸附分析煅制后的牡蛎的孔结构特征。采用电感耦合等离子体发射光谱法（ICP-OES）测定样品中CaCO3的含量。结果：约500℃煅制,会导致生石灰的含量显著升高。300℃以下煅制3~4 h后取出,牡蛎表面形成的孔道明显。在300℃以下煅制形成的样品比表面积较大。300~350℃煅制的牡蛎中CaCO3含量较高。结论：在煅制牡蛎时,应以300℃左右为宜,煅制时间3~4 h,这样有利于形成孔道结构,保证较大的比表面积和较高的CaCO3含量,有利于煎煮和药效的发挥。

Objective： To study on the microstructural changes of Ostreae Concha in the calcining process,and the effect of temperature and time on calcined Ostreae Concha were investigated. Method： Raw products of Ostreae Concha was analyzed by thermogravimetric/differential scanning calorimetry（TG/DSC）.Ostreae Concha was placed in a porcelain crucible,under the conditions of different temperatures,the samples were calcined by the oven,and the Ostreae Concha was removed at every different time. After grinding,200 mesh sieves were used. The surface of calcined Ostreae Concha was analyzed by scanning electron microscope（SEM）. The pore structure characteristics of calcined Ostreae Concha were analyzed by BET（Brunauer-EmmettTeller） nitrogen adsorption. The content of CaCO3 in samples was determined by inductively coupled plasma optical emission spectrometer（ICP-OES）. Result： Calcining at about 500 ℃ led to a significant increase in the content of quicklime. After being calcined under 300 ℃ for 3-4 h,the pore canal were formed on the surface of Ostreae Concha. The specific surface area formed by calcining under 300 ℃ was larger. The content of CaCO3 in Ostreae Concha was higher by calcining between 300-350 ℃. Conclusion： When calcining Ostreae Concha,it should be suitable at about 300 ℃,and the calcination time should be 3-4 h. Under these conditions,it will help to form pore structure, ensure large specific surface area, increase the content of CaCO3,and facilitate the development of decoction and efficacy.