Alteration of abandoned mine sites and wastes generates variable secondary mineral phases that incorporate different toxic trace elements with a prospective threat to the neighboring ecosystems. The main focus of this study was to investigate the mineralogical and geochemical changes at neutral pH where dry condition prevails around oxidation-primary contacts interface and the surface in Um Gheig Pb/Zn mine, Eastern Desert, Egypt. The secondary minerals were determined by M4 Tornado μ-EDXRF, Raman microscope and scanning electron microscopy with energy-dispersive system. Two alteration zones were recognized depending on ion availability and the Eh/pH conditions. The first include anglesite as an initial phase that quickly transformed into a more stable cerussite and hydrocerussite. Mendipite formation was controlled by the availability of Cl⁻ ions in the solution. Hemimorphite was formed after sphalerite in the pore spaces, depending on the accessibility of Si ions from silicates dissolution. Iron (oxy) hydroxides were formed in a later stage due to their restricted mobility in carbonates. The second zone includes gypsum and anhydrite formed at the surface of the mine wastes due to continuous evaporation in arid environments. These secondary mineral phases can undergo different mineral transformations depending on the prevailing conditions. The element release ratios in the mine surface zone compared to the capillary fringe zone reached 12.1, 2.8, 1.6, 0.17, 0.09 and 0.03 for Sr, Cr, Pb, Zn, Cu, and Ni in the mine surface zone compared to 5.86, 0.01, 0.05, 0.02, 0.07 and 0.01 in the capillary fringe zone. The findings from this investigation have important implications for the management and the control of elements mobility from secondary phases formed in mined areas.

废弃矿山场址和废物的改变会产生可变的次生矿物相，其中包含不同的有毒微量元素，对邻近的生态系统构成潜在威胁。这项研究的主要重点是研究在埃及东部沙漠Um Gheig Pb / Zn矿山的氧化主要接触界面和地表周围处于干燥条件下的中性pH下的矿物学和地球化学变化。通过M4龙卷风μ-EDXRF，拉曼显微镜和能量分散系统的扫描电子显微镜确定次生矿物。根据离子的可用性和Eh / pH条件，识别出两个改变区。首先包括角质岩作为初始阶段，该阶段迅速转变为更稳定的陶粒和水陶粒。氯的可利用性控制了门迪普岩的形成^-溶液中的离子。闪锌矿之后，在孔隙空间中形成了半晶石，具体取决于硅酸盐溶解过程中硅离子的可及性。由于氢氧化铁（氧）在碳酸盐中的流动性受到限制，因此在后期形成。第二区域包括由于在干旱环境中的连续蒸发而在矿山废料表面形成的石膏和硬石膏。根据主要条件，这些次生矿物相可能会经历不同的矿物转化。矿山表层中的Sr，Cr，Pb，Zn，Cu和Ni的矿山表面区域中的元素释放率与毛细管边缘区域相比分别达到12.1、2.8、1.6、0.17、0.09和0.03，而5.86、0.01 ，0.05、0.02、0.07和0.01。