Development of a Neutral Mine Drainage Prediction Method Using Modified Kinetics Tests and Assessment of Sorption...

Area of Science:

• Environmental Science
• Geochemistry
• Mining Engineering

Background:

• Predictive tools for acid mine drainage (AMD) are inadequate for neutral mine drainage (NMD).
• Assessing NMD risk requires specialized methodologies.
• Lac Tio Mine waste rock serves as a case study for NMD risk assessment.

Purpose of the Study:

• Develop and validate a methodology for assessing NMD risk.
• Evaluate the potential for nickel (Ni) release from Lac Tio Mine waste rock.
• Provide a tool for predicting water quality risks associated with NMD.

Main Methods:

• Combined waste rock's total metal content and sorption capacity (qmax) for contaminant release potential.
• Conducted mineralogical assessment and modified kinetic leaching experiments.
• Utilized a chelating agent (ethylenediaminetetraacetic acid, EDTA) to prevent metal immobilization during leaching.

Main Results:

• The proposed methodology indicates a probable NMD risk for Lac Tio waste rock.
• Total nickel concentrations in waste rock range from 270 to 590 mg/kg.
• Nickel is present in Ni-rich pyrites and leaches effectively under non-immobilizing conditions; sorption capacity to total Ni ratio is < 1.

Conclusions:

• The developed methodology provides a reliable assessment of NMD risk.
• Lac Tio waste rock poses a significant potential risk for nickel leaching over time.
• This approach enhances the ability to predict and manage water quality impacts from NMD.