纤维矿物粉尘在Gamble溶液中的溶解行为

Dissolving Behavior of Fibrous Mineral Dusts in Gamble Solution

本文用人工配制的Gamble溶液和三个酸度系列 ,研究了 6对粉尘在模拟人体环境下 96d的溶解特征和生物持久性。结果表明 :不同粉尘中铁元素的溶解速率多数出现两个峰值区 ,三八面体结构型粉尘中铁与镁元素溶解同步。高镁矿物粉尘溶解速率在第一阶段多出现峰值 ;沸石、硅灰石的钙溶解速率比较稳定 ,硅灰石在低 pH值区表现出前高后低的特点 ;Si在Gam ble溶液中的溶解峰点在pH5体系中出现在 48d以前 ,在pH7体系中出现在 48d以后 ;Al则表现为在pH3和 pH5体系中易于出溶而在pH7体系中难于出溶。纤维矿物粉尘中的所有元素在Gamble溶液中的累计溶解总量均随时间的增长而增加 ;纤状样品的溶解总量多大于土状样品。溶液作用过程中纤维矿物表面有裂开、凹蚀、脱皮现象并趋向分散或折断 ;片状粉尘颗粒溶解速率与台阶步密度或与含铁样品的氧化速率正相关 ,溶解总量基本与体系酸度和有机离子的总量成正比。富钙、镁或铝的粉尘溶解速率高于富钾、硅的粉尘。环境的低 pH值、高溶解氧量或氧化反应、高盐溶液均可促进溶解。

The dissolving characters and bio_resistance of 6 pairs of mineral dusts in a simulated human body environment for 96 days were studied by using Gamble solution and three acid series. The results show that the iron dissolving rates in most mineral dusts have two peaks, and that magnesium is dissolved simultaneously with iron in dusts with tri_octahedral structure. Most of the dissolving rates of high_magnesium mineral dusts display peaks in the first dissolving stage. The calcium dissolution rates of zoelite and wollastonite are relatively stable, and wollastonite show the feature of being high in the front and low in the rear in the low_pH area. The dissolution peak of Si appeared in the first 48 days in Ph5 Gamble solution, but after 48 days in the pH7 series. Al dissolution is easy in the pH3 and pH5 series and difficult in pH7. The cumulate dissolution amount of all elements in Gamble solution of fibrous mineral dusts increases with time, and the total dissolution amount of fibrous samples is mostly larger than that of the clayey ones. There are phenomena of cracking, etching and peeling on the surface of fibrous minerals and fibers tend to be scattered or break during dissolution. The dissolving rate of flaky dusts is positively correlated to the step densities and oxidizing rate of iron_bearing samples. The total dissolution amount is basically positively proportional to the system acidity and total organic ions. The dissolving rate of Ca_, Mg_ or Al_rich mineral dusts is higher than that of K_ or Si_rich dusts. The low pH, high solubility of O 2 or oxidizing reaction and high salinity solution of the environment may accelerate the dissolution of dusts.