油页岩中几种微量元素的赋存形态

Geochemical occurrences of selected trace elements in oil shale

选用桦甸油页岩和汪清油页岩,采用逐级化学提取方法研究了10种微量元素Ba、Co、Cr、Cu、Ni、Pb、Sr、V、Y、Zn等在油页岩中的赋存状态;并采用电感耦合等离子体原子发射光谱法(ICP-AES)测定了页岩及其各提取状态中元素的含量.分析了油页岩中Pb、Cu、Ni、Zn等10种元素的环境化学活动性.研究结果表明:2个矿区页岩中除Ba、Pb、Sr和V这4种元素外,其余元素主要是以硫化物结合态及残渣态存在,这2个状态的质量分数之和为78.96%～97.97%,其中残渣态占据50%以上的比例;残渣态主要为硅酸盐结合态,其化学活性小,对环境的危害性较小,此形态以汪清页岩中的Cr为代表,其质量分数为80.87%;而以Sr为代表的元素在表生条件下很容易被带出油页岩,主要以残渣态以外的形态存在,桦甸页岩中其潜在可淋失率达到了77.67%,对环境的潜在危害性较大.

Sequential chemical extraction has been used to determine the mode of occurrence of Ba, Co, Cr, Cu, Ni, Pb, St, V, Y, Zn in samples of tow China oil shales： Jilin Huadian and Jilin Wangqing. The concentration of trace elements in oil shale and sequential chemical extraction states were determined using inductively coupled plasma atomic emission spectroscopy. The results show that trace elements of oil shale mainly exist as sulfide state and residue state except for Ba, Pb, Sr and V. The concentration in both of these conditions accounts for 78.96% - 97.97% , where the residue state occupies more than 50%. The residue state has low mobility and the extent of pollution to environment was weak. For example Cr in Wangqing oil shale, accounts for 80.87% in the residue state. The elements which are easily extracted from oil shale have a higher mobility, so these types of elements might seriously pollute the environment if they mainly exist in forms other than the stable state. In particular, we should pay attention to Sr, because its potential leaching rate was up to 77.67% in Huadian oil shale.