PAPER SLUDGE ASH AS A PRECURSOR FOR PRODUCTION OF ALKALI-ACTIVATED MATERIALS
Paper sludge is a residue of the paper making process with the main recycling and disposal routes including land-spreading as agricultural fertiliser,incineration in combined heat and power plants at the paper mill (producing paper sludge ash (PSA)) and disposal in landfill.This study evaluates the feasibility of producing alkali-activated binders using paper sludge ash as sole raw material.The structural development of mixes based on PSA with water and PSA with sodium silicate solutions is assessed.The results indicate that the hydration of the PSA proceeds in the absence of alkalis,where the main reaction products are portlandite,derived from the hydration of quick lime,and Al-rich phases including C4AH13,calcium monocarboaluminate,and C-A-S-H type gel.At moderate concentrations of activation (7 wt.% Na2O) similar compounds to those identified in hydrated PSA are observed; however,a higher extent of reaction of PSA seems to take place at early age (7 days) compared with water-hydrated PSA.Formation of an aluminosilicate geopolymer gel was not clearly identifiable,which indicates that the activation reaction of the aluminosilicate-type component present in the PSA is not promoted under the activation conditions assessed.
Alkali-activated aluminosilicate paper sludge ash sodium silicate X-ray diffraction spectroscopy
Susan A.Bernal Richard J.Ball Oday Hussein Andrew C.Heath John L.Provis
Department of Materials Science and Engineering,University of Sheffield,Sheffield,S1 3JD,United King Department of Architecture and Civil Engineering,University of Bath,Bath,BA2 7AY,United Kingdom
国际会议
长沙
英文
71-80
2014-06-01（万方平台首次上网日期，不代表论文的发表时间）