Adsorption-Desorption of Critical Metals from Simulated Acid Mine Drainage by Metakaolin Geopolymer

Ball-milling effect on Indonesian natural bentonite for manganese removal from acid mine drainage

MATEC Web of Conferences ◽

10.1051/matecconf/201815603046 ◽

2018 ◽

Vol 156 ◽

pp. 03046 ◽

Cited By ~ 1

Author(s):

Widyawanto Prastistho ◽

Winarto Kurniawan ◽

Hirofumi Hinode

Keyword(s):

Particle Size ◽

Acid Mine Drainage ◽

Particle Size Distribution ◽

Size Distribution ◽

Mine Drainage ◽

Nitrogen Adsorption ◽

Exchange Capacity ◽

Manganese Removal ◽

Acid Mine ◽

Adsorption Desorption

The influences of mechanical milling on Indonesian Natural Bentonite (INB) characteristics and manganese (Mn) removal from acid mine drainage (AMD) were investigated. The INB characteristics were observed by scanning electron microscope (SEM), X-ray diffraction (XRD), nitrogen adsorption-desorption for specific surface area (SSA) and microporosity measurement, cation exchange capacity (CEC) and particle size distribution (PSD) analyzer. Four minutes milling with frequency 20 Hz on INB caused morphological change which showed more crumbled and destructed particle, lost the (001) peak but still retained the (100) peak that indicated delamination of montmorillonite mineral without breaking the tetrahedral-octahedral-tetrahedral (T-O-T) structure, rose the CEC from 28.49 meq/100g to 35.51 meq/100g, increase in the SSA from 60.63 m2/g to 104.88 m2/g, significant increase in microporosity which described in the t plots and decrease in the mean particle size distribution peak from 49.28 μm to 38.84 μm. The effect of contact time and effect of adsorbent dosage on Mn sorption was studied. Both unmilled and milled samples reached equilibrium at 24 hours and the pH rose from 4 to 7 in first 30 minutes. The Mn removal percentage increased significantly after milling. Using Langmuir isotherm, the maximum adsorbed metals (qmax) also increased from 0.570 to 4.219 mg/g.

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Release of technology critical metals during sulfide oxidation processes: the case of the Poderosa sulfide mine (south-west Spain)

Environmental Chemistry ◽

10.1071/en19118 ◽

2020 ◽

Vol 17 (2) ◽

pp. 93 ◽

Cited By ~ 3

Author(s):

Carlos Ruiz Cánovas ◽

Francisco Macías ◽

Manuel Olías ◽

Maria Dolores Basallote ◽

Rafael Pérez-López ◽

...

Keyword(s):

Acid Mine Drainage ◽

Chemical Weathering ◽

Natural Waters ◽

Mine Drainage ◽

Anthropogenic Activities ◽

Sulfide Oxidation ◽

Critical Metals ◽

Critical Elements ◽

Acid Mine ◽

South West

Environmental contextNatural weathering of rocks may release technology critical elements (TCEs) to the environment, and anthropogenic activities can noticeably increase TCE release rates. We investigated acid mine drainage outflows from an underground sulfide mine in south-west Spain, reporting TCE concentrations orders of magnitude higher than those observed in natural waters. The findings improve our knowledge on mobility of TCEs in different geological settings. AbstractExtensive extraction of technology critical elements (TCEs) from the lithosphere and their use results in a growing dispersion and remobilisation of these elements within the environmental compartments. We investigated the concentration and mobility of different TCEs (rare earth elements (REEs), Sc, Y, Ga and Tl) in acid mine drainage (AMD) outflows from a massive sulfide underground mine in south-west Spain for around 2 years. High levels of TCEs were observed; average concentrations of 8.2mgL−1 of REEs, 1.5mgL−1 of Y, 80µgL−1 of Ga, 53µgL−1 of Sc and 42µgL−1 of Tl were reported, several orders of magnitude higher than those observed in natural waters. The TCEs source in the study site is primarily accessory minerals in the host rocks, although the contribution of Ga and Tl by sulfides cannot be discarded. A seasonal variability in TCEs is observed in AMD waters, although their maximum concentrations do not coincide with those of sulfide-related elements. TCEs seem not to be controlled by the precipitation of secondary minerals, but by the intensity of chemical weathering inside the mined zone. A positive correlation between REEs and the Si/Na+K ratio seems to indicate that these elements are linked to resistant minerals to weathering.

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