超微粉碎对牡蛎壳粉体学性质和溶出度的影响

目的:考察超微粉碎对牡蛎壳粉体学性质和溶出度的影响,为牡蛎壳综合开发利用提供实验依据。方法:牡蛎壳以粉碎机制备成普通粉,再将普通粉以超微粉碎机制备成微粉Ⅰ(粉碎5 min)和微粉Ⅱ(粉碎10 min)。从粉体粒径分布、比表面积、孔隙度、休止角、堆密度、吸湿率等方面考察牡蛎壳超微粉碎前后的粉体学差异,采用扫描电镜、傅里叶变换红外光谱(FTIR)和X射线衍射(XRD)等分析其形态特征和化学结构的变化情况,并考察其溶出度。结果:与普通粉比较,微粉Ⅰ和微粉Ⅱ粒径小且分布均匀,但粒子易黏附聚集,比表面积、孔隙度及休止角增大,堆密度减少,吸湿性增强;FTIR和XRD图谱显示牡蛎壳超微粉碎后化学结构无明显变化。微粉Ⅱ和微粉Ⅰ在10 min时溶出度分别为18.5%和10.3%,普通粉在60 min时溶出度只有6.4%。结论:与普通粉比较,牡蛎壳超微粉碎后的粉体学性质呈现出明显差异,粉体溶出度增加,化学结构未发生明显变化。

Effects of Superfine Grinding Technology on Powder Properties and Dissolution of Oyster Shell

OBJECTIVE:To study the effects of superfine grinding on the powder properties and dissolution of oyster shell,and to provide experimental basis for its comprehensive exploitation. METHODS:Oyster shells were firstly prepared into ordinary powder by grinder. Then the ordinary powder was prepared into micro-powder Ⅰ(crushing 5 min)and Ⅱ(crushing 10 min)by ultrafine pulverizer. The differences of micromeritic properties were investigated before and after superfine grinding from the aspects of particle size distribution,specific surface area and porosity,angle of repose,bulk density,hygroscopicity,etc. Scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR)and X-ray powder diffraction(XRD)techniques were used to analyze the morphological characteristics and chemical structure of oyster shell before and after superfine grinding. The dissolution were investigated. RESULTS:Compared with ordinary powder,micropowder Ⅰ and micropowder Ⅱ’s were small in particle size and uniformly distributed,but the particles were easy to adhere and aggregate;the specific surface area,porosity and the angle of repose increased,while bulk density decreased;the hygroscopicity increased. FTIR and XRD showed no significant change in chemical structure of oyster shell after superfine grinding. The dissolution rate of micropowder Ⅱ and micropowder Ⅰwas 18.5% and 10.3% at 10 min,and the dissolution of ordinary powder was only 6.4% at 60 min. CONCLUSIONS:Compared with ordinary powder,oyster shell show obvious differences in powder properties after superfine grinding;the dissolution rate of the powders increases,and there is no significant change in chemical structure.