Possibilities of fly ash activation in alumina recovery process

International Conference Building Materials, Products and Technologies

材料科学;工业技术（总论）

Marko, M.^1 ; Opravil, T.^1 ; Masilko, J.^1 ; Porizka, J.^1

Brno University of Technology, Faculty of Chemistry, Purkynova 468/118, Brno

61200, Czech Republic^1

关键词: Acid concentrations;    Ash activation;    Calcium aluminate;    Cement production;    Chemical and phase compositions;    Chemical compositions;    Recovery process;    Sintering reaction;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/583/1/012003/pdf
DOI  :  10.1088/1757-899X/583/1/012003

来源: IOP

【 摘 要 】

This paper summarises various possibilities of higherature fly ash (HTA) and fluidised-bed filter ash (FFA) activation in metal and oxides recovery processes (esp. alumina recovery). The study deals with chemical and phase composition ash modification to improve leachability of aluminium compounds into sulphuric acid solution. Samples of HTA and FFA produced by power plant industry in the Czech Republic were subjected to diverse types of modification, such as sulphuric acid concentration, ash/acid ratio and sintering reactions using several types of solid agents. Sintering reaction were based on forming acid soluble calcium aluminates via donating the system with calcium oxide,-carbonate and-chloride. Phase and chemical composition were characterised by means of XRD and XRF analysis and the concentration of Al in acid solutions via ICP-OES. Appropriate modification of input material by higherature sintering reaction using calcium chloride combined with extraction into 10 wt. % sulphuric acid leads to dissolution up to 99% of aluminium from FFA and up to 94% form HTA. At least, irreplaceable dopant for cement production-gypsum, is formed as a by-product of leaching.