Distribution of Zinc, Copper, and Iron in the Tailings Dam of an Abandoned Mine in Shimokawa, Hokkaido, Japan

Abstract

This paper addresses the mechanism of acid mine drainage generation in tailings from an abandoned mine site and predicts the evolution of zinc (Zn), copper (Cu), and iron (Fe) concentrations. Batch leaching experiments and sequential extractions were conducted to investigate the leaching behavior of these contaminants from the tailings and to understand their solid-phase partitioning. Acid-base accounting and principal component analysis (PCA) were used to confirm factors affecting Zn, Cu, and Fe leaching and acid formation based on the leaching experiments. There were strong positive correlations between Zn, Fe, or EC and SO4 2-, indicating that pyrite and sphalerite are the major minerals releasing Zn and Fe. This aligns with the PCA results. In the upper part of the tailings, the water-soluble and sulfide fractions of Zn, Cu, and Fe were almost flushed out, whereas they remained high in the deeper tailings. This implies that the tailings will likely continue to release these contaminants (Zn > Cu > Fe) for a long time unless remedial measures are taken.

Long-term acid generation and heavy metal leaching from the tailings of Shimokawa mine, Hokkaido, Japan: Column study under natural condition

“…The lower pH values and leaching concentrations were found at the top tailings, and in overall the leaching concentration followed the order of case 1 > case 2 > case 3. However, the fact that the higher concentrations of Cu, Zn, Fe, and SO4 2were found in the deeper tailings sample agreed with the results of the field observation by Khoeurn et al (2018). These results indicate that the exchangeable phase was almost flushed out from the top tailings (Fig.…”

“…The tailings were produced from mining processes of gold (Au), silver (Ag), Cu, cobalt (Co), Zn, and iron sulfide. The details were described by Khoeurn et al (2018). The tailings samples were collected at the depth of 1-3 meters because the samples were not weathered and contained higher amounts of Cu, Zn, and Fe.…”

“…A closed mine site in Hokkaido has generated AMD for more than 40 years. Mine tailings were the major source of Cu, Zn, Fe, and SO4 2- (Khoeurn et al, 2018). Thus, the AMD has been treated with calcium hydroxide (Ca(OH)2) before the effluents are discharged into the nearby river.…”

Static Test-Based Acid Rock Drainage Formation Potential of Metalliferous Tailings from O’Kiep, South Africa

“…In general, the primary minerals in the MTs are quartz and pyrite, with secondary minerals such as goethite. Acid rock drainage (ARD) from such MTs is generated by the moisture-based weathering and oxidation of sulfide minerals such as pyrite [10]. ARD management approach is neutralization by an alkaline reagent such as limestone to raise the pH and remove most of the PTEs through precipitation reactions [10,11].…”

“…Acid rock drainage (ARD) from such MTs is generated by the moisture-based weathering and oxidation of sulfide minerals such as pyrite [10]. ARD management approach is neutralization by an alkaline reagent such as limestone to raise the pH and remove most of the PTEs through precipitation reactions [10,11]. O'Kiep MTs are potentially primary contributors to ARD due to their high sulfide content [12].…”