Long-term leaching characteristic study of coal processing waste streams.

Area of Science:

• Environmental Science
• Geochemistry
• Waste Management

Background:

• Coal processing generates waste materials with potential for hazardous trace element release.
• Understanding element mobility is crucial for effective environmental protection and waste management.

Purpose of the Study:

• To investigate the mobility of trace elements from coarse and fine coal processing waste.
• To compare leaching characteristics under different environmental conditions.
• To inform optimal disposal practices for coal waste.

Main Methods:

• Utilized baseline and kinetic leaching tests to simulate waste storage conditions.
• Analyzed mineralogy of coarse and fine refuse using X-ray diffraction.
• Characterized leachate pH and trace element concentrations.

Main Results:

• Significant mineralogical differences observed between coarse (higher pyrite) and fine (higher clay, calcite) refuse.
• Coarse refuse with medium-to-high pyrite exhibited acidic leachate and highest trace element release.
• Fine refuse showed circumneutral leachate with lower trace element release.
• Low pyritic refuse streams released minimal trace elements.

Conclusions:

• Waste material mineralogy dictates trace element mobility and leaching behavior.
• Segregation of coal pyrite and co-disposal of coarse and fine refuse streams are recommended for effective waste management.