Speciation, Fate and Transport, and Ecological Risks of Cu, Pb, and Zn in Tailings from Huogeqi Copper Mine, Inner Mongolia, China

Abstract

Tailings collected from the tailing reservoir at Huogeqi Copper Mine, located in Inner Mongolia, China, were used in a leachate study to evaluate the acid potential, neutralization potential, and possibility for producing acid mine drainage (AMD) from the site. The speciation of Cu, Pb, and Zn contained in the tailings was also determined during the leachate study to further access the potential migration abilities of these metals. The results showed that the tailings did not produce significant AMD as the pH of the leachate ranged from 7 to 9 and decreased with time. The Cu, Pb, and Zn concentrations were high, ranging from 439.1 to 4527 mg/kg in the tailings and from 0.162 to 7.964 mg/L in the leachate, respectively. Concentrations of metals in the leachate and tailings were positively correlated. Over 60% of the Cu in the tailing samples existed in an oxidizable form. Most of the Pb also existed in its oxidized form, as did the silicate and Zn. Metals usually have higher mobility in their exchangeable and oxidizable forms and as such represent a higher potential risk to the environment. Results of risk assessment code also revealed that metals in tailings exerted medium to high risks to the environment.

Speciation, risks and isotope-based source apportionment of trace elements in soils of the northeastern Qinghai–Tibet Plateau

“…Copper existed in soils bound to the residual fraction (71.6%) and the organic fraction (18.4%). The chemical speciation of Cu in soils of the study area was significantly different from that in the tailing samples (Chen et al 2018). Tin and Sb existed mostly bound to the residual fraction (99.7 and 93.0%, respectively), with the rest of the four chemical forms occurring in the range of 0.0-0.2 and 0.4-4.0%.…”

“…Contrary to the other heavy metals, Pb existed in soils mainly bound to the Fe-Mn oxide (38.7%) and the residue (29.9%) fraction. Most of the Pb also existed in the Fe-Mn oxide fraction in the Huogeqi Copper Mine in Mongolia (Chen et al 2018). The exchangeable Pb content in the soils was very low.…”

“…The RAC was calculated as the percentage sum of exchangeable and carbonate forms. Ecological risk was categorized into five levels including safe (RAC <1%), low (RAC in the range 1-10%), medium (RAC in the range 11-30%), high (RAC in the range 31-50%) and dangerous/very high risk (RAC > 50%) according to a previous report (Chen et al 2018).…”

Copper Analysis by Two Different Procedures of Sequential Extraction after Electrodialytic Remediation of Mine Tailings

“…In the research conducted by Chen et al, 2018, the acid and neutralization potential and the possibility for producing acid mine drainage from tailings collected from a reservoir at the Huogeqi mine, located in Mongolia, China, was evaluated. The results showed an insignificant quantity of acid mine drainage, where Cu in the tailing sample existed in an oxidizable form [15].…”

Effect of freeze–thaw cycles on soil physicochemical properties and fractions of Pb and Cr in the northeastern Qinghai–Tibet Plateau

“…Human activities such as industry and mining, along with accelerated development of urbanization and agricultural production increase the ecological risk of pollutants (Chandraiah 2016;Li et al 2018Li et al , 2020aLu et al 2020c;Wu et al 2018). The toxicity of trace elements depends not only on their total concentrations but also their bio-availability (Chen et al 2018;Li et al 2020b). Different chemical fractions, especially the exchangeable fractions, affect the toxicity of trace elements while the chemical fractions and ecological risk of trace elements are obviously influenced by soil components and properties (Xiao et al 2016).…”