Utilisation of coal fly ash in the manufacture of useful materials

[摘要] Fly ash, if not utilised, is considered a waste product. Zeolitisation of coal fly ash offers the opportunity to create an added value product from a waste stream. Optimisation of the two-step zeolitisation process is necessary in order to render the process profitable. The Objective of this thesis is to analyse the optimisation of Si extraction from fly ash and the conditions of crystallisation. The type of synthetic zeolites produced were found to be highly dependent on the conditions of the crystallisation process, which has produced zeolite Na-P1, sodalite, zeolite Na-A, zeolite K-A and other species. Crystallisation parameters explored by this thesis include pH, sodium aluminate addition, time at which ash and leachate are separated, length of crystallisation period, temperature, and control experiments on Si leaching from glassware. Further experimentation analysed the effects of a closed loop system on yield, variations in ash used in the leaching process, generation of floating zeolite via precipitation on cenospheres, highly caustic ash leaching, and Ga and Ge content analysis of ash leachate. Eight sets of cation exchange capacity tests were carried out using synthetic acid mine drainage and various zeolites, zeolitised ash, and untreated ash.

[发布机构] University:University of Birmingham;Department:School of Chemical Engineering

[关键词] T Technology;TA Engineering (General). Civil engineering (General)