褐煤腐植酸中微量金属元素的赋存状态

Occurrence State of Trace Metal Elements in Lignite Humic Acid

以褐煤为原料,采用碱溶酸析法提取腐植酸,光栅摄谱法定性确定含有金属元素钙、铝、铜和钛。采用逐级提取分离法将腐植酸中金属元素分为:可交换态、碳酸盐结合态、氧化物结合态、有机物结合态、残渣态;采用ICP-AES定量测定腐植酸中微量金属元素的赋存状态。结果表明:残渣态铜占99.13%;有机物结合态铝占74.84%、残渣态铝占21.05%;有机物结合态钛占9.04%、残渣态钛占80.18%;可交换态钙占14.14%、有机物结合态钙占11.82%、残渣态钙占68.27%。所以,腐植酸中的铜主要是以残渣态存在,钛和铝主要是以有机物结合态和残渣态存在,钙主要是以可交换态、有机物结合态和残渣态存在。可交换态和氧化物结合态中的金属离子主要是钙、次之是铝;有机物结合态中的金属离子主要是钙、次之是铝和铜;有机物结合态中的金属离子主要是铝、次之是钙。

The occurrence states of trace metal elements in lignite humic acid were researched using grating spectrograph and ICP-AES. Firstly, humic acid was obtained from lignite by alkali extraction and acid precipitation;using grating spectrograph legal identified containing metal elements calcium, aluminum, copper and titanium. Secondly, those trace metal elements in humic acid were divided into five parts ： exchangeable,carbonate bound,oxide bound, organic matter bound,residue, by the method of sequential extraction separation;the content of trace metal elements in those parts were determined using ICP-AES. The results show the 99.13 % distribution of copper in residual;74.84 % distribution of aluminium in organic matter bound, 21. 05% in residual; 9. 04% distribution of titanium in organic matter bound , 80. 18% in residual; 14. 14%distribution of calcium in exchangeable, 11. 820/00 in organic matter bound, 68. 27% in residual. So the element of copper in humic acid is mainly to residual presence,titanium and aluminum is mainly to organic matter binding condition and residual state, calcium is mainly to exchangeable, organic matter binding condition and residual state. Metal ions in exchangeable and oxide bound is mainly calcium,the second is aluminum; organic matter bound metal ions is mainly calcium,the second is aluminum and copper; organic matter bound is mainly aluminum, the second is calcium.