Ca^(2+)对铁氧体法处理酸性矿山废水的影响

EFFECT OF Ca^(2+) ON USING FERRITE PROCESS TO TREAT ACID MINE DRAINAGE

本文探讨了Ca2+对常温铁氧体法处理酸性矿山废水的影响。试验结果表明磁性产物的饱和磁化率和在酸溶液中的稳定性均随废水中初始Ca2+浓度的增加而下降。X-射线衍射分析图谱证明磁性产物具有尖晶石型铁氧体（FeFe2O4）的晶体结构,但其晶格常数较无Ca2+存在时要大,作者认为这是部分Ca2+进入了铁氧体晶格后在其中形成“位错”所致,这种“位错”使磁性产物的饱和磁化率下降。而磁性产物稳定性降低的原因则归结于未进入铁氧体晶格中的那部分Ca2+以离子的形式或与铁离子等形成了不稳定的络合物而吸附在晶粒界面和铁氧体颗粒表面。

Acid mine drainage is one of the major environmental challenges facing thc mining industry. Using a ferrite process to remove iron components seems attractive because the precipitates generated are magnetic,which means they can be effectively magnetically separated from effluent. The calcium ion was found to be detrimental to ferrite formation, resulting in precipitates of reduced saturation magnetization, low recovery and poor stahility. The effect of the ion on ferrite formation at an ambient conditions is discussed in this paper. The X-ray diffraction Pattern for the magnetic precipitate showed that the precipitate is spinel ferrite. The greater lattice constant calculated from the X - ray data than of the precipitate generated in the absence of calcium demonstrated that part of calcium ions were incorporated into the spinel lattice in the form of , dislocation, which resulted in the reduced saturation magnetization. The poor stability due to the presence of calciurn may be attributed to another mechanism: the absorption of part of ions at grain boundaries.