铜陵铜尾矿废弃地中氧化铁研究

[目的]对铜尾矿废弃地中的氧化铁进行研究，探讨不同类型氧化铁对土壤形成过程的影响。[方法]以铜陵2处不同时间弃置的铜尾矿废弃地为对象，采用化学分析法研究了自然生态恢复过程中3类铁氧化物（无定形氧化铁、游离氧化铁和络合态氧化铁）的含量。[结果1尾矿废弃物无定形氧化铁含量为（1．73±0．77）～（9．68±2．94）g/kg，氧化铁活化度为（4．80±3．85）％-（91．94±4．34）％；游离氧化铁、晶质态氧化铁含量和游离度分别为（9．10±1．57）～（42．77±12．69）、（2．50±0．57）～（42．05±13．46）g／kg和（8．17±1．77）％～（20．02．±5．38）％；成土时间较短的杨山冲铜尾矿废弃地不同发育层尾矿中3种氧化铁含量差异较小，而弃置时间较长的铜官山尾矿废弃地随深度增加无定形氧化铁逐渐降低，游离氧化铁和络合态氧化铁逐渐增加。相关分析表明：2处尾矿废弃地pH值与无定形氧化铁含量及氧化铁活化度呈极显著正相关．而与游离氧化铁含量、铁游离度、晶质态氧化铁含量和络合态氧化铁含量呈极显著负相关；有机质含量与无定形氧化铁含量和氧化铁活化度呈极显著负相关，而与游离氧化铁含量、游离度及晶质态氧化铁含量呈极显著正相关.目前，铜陵铜尾矿废弃地尚处于成土过程的初期阶段，大量问题仍有待于进一步研究。[结论]探索了自然生态恢复过程中尾矿废弃地中铁氧化物的形态、含量变化特征及其影响因素，为进一步揭示铜尾矿及类似尾矿废弃物的成土过程、成土机制等理论研究提供参考。

Study on Iron Oxides in Wastelands of Copper Mine Tailings in Tongling

[Objective] According to study of iron oxides in wastelands of copper mine tailings,the effects of different types of iron oxide on soil formation were studied.[Method] By using chemical analysis approach,the contents of iron oxides (amorphous iron oxide,free iron oxide and organic-bound iron) from 2 wastelands of copper mine tailings in the processes of naturally ecological restoration were investigated.[Result] The contents of amorphous iron oxide in wastelands of copper mine tailings were 1.73±0.77-9.68±2.94 g/kg.And activation degree of iron oxides reached (4.80±3.85)%-(91.94±4.34)%.However,the contents of free iron oxide and crystal iron oxide and the free degree of iron oxide in wastelands of copper mine tailings were only (9.10±1.57)-(42.77±(12.69),(2.50±0.57)-(42.05±13.46) g/kg and (8.17±1.77)%-(20.02±5.38)% respectively.There was not significant difference for 3 types of iron oxides between different horizons in Yangshanchong wasteland of copper mine tailings.The contents of amorphous iron oxide and organic-bound iron decreased and the content of free iron oxide increased with depth in old Tongguanshan wasteland of copper mine tailings.And data analysis showed that there was a significant difference for 3 types of iron oxides between different horizons in old Tongguanshan wasteland of copper mine tailings.Data analysis also displayed that there was a significant positive correlation between pH value and the amorphous iron oxide content,the activation degree of iron oxides,and a significant negative correlation between pH value and the free iron oxide content,the free degree of iron oxide,the crystal iron oxide and organic-bound iron contents.However,there was a significant negative correlation between the organic matter content and the amorphous iron oxide content,the activation degree of iron oxides,and a significant positive correlation between the organic matter content and the free iron oxide content,the free degree of iron oxide and the crystal iron oxide content.At present,the pedogenesis of two wastelands of copper mine tailings on Tongling is at earlier stage,more research works should be done in the future.[Conclusion] The shape,content change characteristics of wastelands of copper mine tailings during natural restoration and its influencing factors,which provide reference for soil forming process and soil forming mechanism of the castoff of copper mine tailings and similar mine tailings.