Content area
Full Text
ABSTRACT
In recent years we have observed a rapid increase in the demand for rare earth elements (REEs), related to industry intensive development in the field of new technologies. The biggest producer of REEs is China, which provides global markets with more than 83% of the whole amount of rare earth elements. It is worth mentioning that China has access to rich deposits of REEs, accounting for ca 37% of these metals resources available all over the world. For this reason, alternative possibilities to obtain rare earth elements are becoming increasingly important. In the work the potential and forms of rare earth elements (REEs) occurrence in acid mine drainage (AMD), produced as a result of hard coal mining in the Upper Silesian Basin have been presented. The results of initial investigations into the contents of rare earth elements in acid waters from the drainage of an active hard coal waste tip located in Libiąż, in the south of Poland, have been discussed. Field measurements of selected parameters of tip leachates (temperature, pH, electrolytic specific conductivity, redox potential, dissolved oxygen) have been taken. Rare earth elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). The conducted investigations have demonstrated that acid waters flowing from hard coal waste storage sites are much richer in REEs compared to waters which fill old excavations resulting from other minerals mining. In the work the possibility of using acid mine drainage to obtain REEs has been demonstrated. Factors influencing the differentiation of rare earth elements contents in acid waters in view of the possibility to reuse them have been discussed. Attention was drawn to the phenomenon of environmental pollution in mining areas caused by acid mine drainage leachates, also in the context of REEs release into the environment.
Keywords: acid mine drainage (AMD), rare earth elements (REEs), mining waste.
1.INTRODUCTION
The term „rare earth metals" was initially used to refer to oxides of elements belonging to the third subgroup of the periodic table (IIB), lanthanides with an atomic number ranging from 58 (cerium) to 71 (lutetium). Currently this term refers to the following elements from the group of lanthanides: cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho),...