淋溶条件下石英砂柱中铁锰氧化物的形成特点  

The formation characteristics of iron and manganese oxides in the quartz sand columns under the leaching condition

作　　者：吴新亮[1] 顾沛[1] 王贻俊[1] 刘凡[1] 黄丽[1] 

机构地区：[1]华中农业大学农业部长江中下游耕地保育重点实验室,湖北武汉430070

出　　处：《岩石矿物学杂志》2013年第2期221-231,共11页Acta Petrologica et Mineralogica

基　　金：教育部博士点基金资助项目(20110146110027);国家自然科学基金资助项目(40971143)

摘　　要：用不同浓度铁锰离子混合溶液对石英砂柱进行40次淋溶实验,研究砂柱中铁锰氧化物的形成状况。结果表明,淋出液中铁锰离子浓度与其pH值随着淋溶次数的增加呈现先降低后升高的趋势;各处理所形成的铁锰氧化物含量之间存在极显著差异,淋溶液中铁锰离子浓度越大,形成的铁锰氧化物含量越高,当淋溶液中铁锰摩尔浓度比即c(Fe2+)/c(Mn2+)为2:1时最有利于铁锰氧化物的形成;随着淋溶次数的增加,铁锰氧化物含量的增长逐渐减慢;不同层次铁锰氧化物含量差异显著,下层(20～30cm)含量明显高于其它层次;各阶段(每淋溶10次为一阶段)不同形态(非晶形态、晶形态)铁锰氧化物含量间的相关性存在差异,铁锰氧化物尤其是非晶形态的相对比例(Fe/Mn)随着淋溶次数的增加逐渐增大。The formation characteristics of the iron-manganese oxides were studied by leaching the quartz sand columns periodically with different concentrations of mixed iron and manganese ions for forty times. The results were as follows： （1） With the increasing leaching times, the concentrations of iron and manganese ions and pH value of leaching liquids generally exhibited decreasing first and increasing afterwards. （2） Iron and manganese oxides produced under different treatment conditions showed extremely significant difference in content. The higher the concentrations of iron and manganese ions in the treatments were, the higher the content of iron and manganese oxides coated on the sands was. The condition that the molar concentration ratio of iron and man- ganese ions of leaching liquid was 2 ： 1 seemed to be the most favorable condition for the formation of iron and manganese oxides. With the increase of leaching times, the increase of iron-manganese oxides content slowed down. The content of iron and manganese oxides in different layers of sand columns showed significant differ- ence. The content of oxides in the sub-layer （20--30 cm） was obviously higher than that in the other layers. （3） The correlations between different forms （amorphous form and crystal form） of iron oxides and mangnese oxides in various stages （ten leaching times comprising one stage） showed difference, and the ratio of iron and man- ganese oxides, especially in amorphous form, rose with the increase of leaching times.

关 键 词：石英砂柱 铁锰氧化物 淋溶 形成 地球化学 

分 类 号：P578.4[天文地球—矿物学] P579[天文地球—地质学]