Alternative Options of Selected Metals Removal/Recovery from Mine Waters Flowing out from the Flooded Mining Workings of Siderite Ores Deposit NI?NÁ SLANÁ

The objective of this work is the application of innovative method for metals recovery from metalliferous mine water released from the flooded siderite mine Ni?ná Slaná. Although the metals contained in mine drainage are considered environmental pollutants, they may also be valuable resources. Conventional chemical precipitation processes produce huge amounts of sludge with storage and management requirement, without possibility of waste metals processing. This study comprehensively investigated the selective recovery of Fe and Mn from mine water. After oxidation and partial precipitation of iron using hydrogen peroxide, precipitation by sodium hydroxide was applied to the residue iron removal from mine water. In the next step potassium permanganate was used to eliminate manganese by oxidative precipitation. ORP and pH of the solutions were recorded in the course of oxidation/precipitation processes. The morphology and elemental composition of the products were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The recovery efficiencies of Fe and Mn from mine water reached 98.4 % and 96.7 %, respectively. Targeted metals were removed with high selectivity to levels that meet water quality criteria for save discharge to the environment.