Mineralogical and Leaching Characteristics Of Weathered Industrial Ash

It has been observed that waste materials from high-temperature processes are thermodynamically unstable in the natural environment and weather in a similar fashion to volcanic ash. The large surface area, small particle size and high pH enhance natural weathering processes. Experiments were conducted on municipal solid waste incinerator ash material to accelerate the individual mechanisms involved in this geochemical transformation process (dissolution, precipitation, carbonation and pH reduction) and pH-dependent leaching experiments were used to characterize changes in the availability of lead in the weathered materials. The development of crystalline mineral material with artificial weathering was compared with naturally aged pulverized coal fly ash, as well as previous experimental materials, to determine a concurrence in the artificial weathering method used to natural weathering products. Use of x-ray powder diffraction and scanning electron microscopy show more defined crystalline mineral composition of the naturally weathered and artificially weathered ash materials when compared to carbonated or fresh ash materials. The use of elevated temperatures in addition to increase pressures and varying moisture contents proved to be comparable to natural weathering processes in initial weathering product tendencies. However combined weathering methods of carbonation and artificial weathering proved more effective at reduction of lead leaching than did either method alone.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 11p

Subject/Index Terms

Filing Info

  • Accession Number: 01532321
  • Record Type: Publication
  • Contract Numbers: RMRC Research Project No. 3/4
  • Files: TRIS, ATRI, USDOT
  • Created Date: Jul 9 2014 3:55PM