förbättrad behandlingsmetod för slaggrus improved treatment of … · 2019. 12. 4. · improved...
TRANSCRIPT
Förbättrad behandlingsmetod
för slaggrus
Improved treatment of bottom ash –
pilot scale test
Lale Andreas
LTU, AvfallsteknikTest areas at Boden Energi
power plant
Motivation for the choice of treatment
• Simple, cheap
• Accelerated aging
• Carbonation to reduce pH and leaching of trace elements
• Zero valent iron (Fe0)
• Used in soil remediation to stabilize heavy metals
• Trace elements bind to Fe-oxides
• Increases the number of sorption sites
• By-product from the steel industry
Background
• 800 000 t/a bottom ash from waste incineration
• Used as landfill cover material or are landfilled
• Potential as secondary construction material – IF we can control the hazards
• Study: Effect of carbonation and Fe amendment on MSWI BA leachingcarbonation and Fe amendment
• Design of test areas
• Application for permit (to Boden municipality / Norrbottens county administration)
• Characterisation of ashes – twice! 2016/17 and 2018
• Construction of test areas
• Sampling of infiltrated water four times and emptying of wells and lysimeters
• Online monitoring of temperature and precipitation
Activities in the project
Test areas at Boden energi power plant (BEAB)
Provyta 1
Åldrat slaggrus + Fe0
Referensyta 2
Makadam
Provyta 3
Åldrat slaggrus
14 m
12 m12 m 12 m
3 st. brunnar ø 1 m med tät botten; nivåmätare och dränkbar pump; el 230 V, värme
Mätbodel 230 V,
värme
Aged
bottom ash
Crushed
rock
Aged
bottom ash
with Fe0
Test areas at Boden energi power plant (BEAB)
August 2018 September 2018
October 2018
October 2019August 2019
Results and lessons learned
• Delay of necessary permits can devastate time planning and lead to loss of results and
money.
• Used ashes differ a lot from earlier characterised ashes (total composition and leaching
behaviour) → less applicable results.
• Stabilising effect of Fe0 on the mobility of contaminants – confirmed in lab test but opposite
trend in the field.
• Reference material leaches less regarding most elements but more Co, Cu, Mn, Mo and Ni.
• The ash has an insulating effect, especially the bottom ash without Fe0
Next steps
• Final evaluation and reporting/publishing
• Conclusions towards possible uses alternative landfilling of the
bottom ashes (TLR 7)
• Discussions with BEAB about continued monitoring
Ash sorting and metal recycling