Open AccessParameters Affecting the Precipitation of Al Phases from Aluminate Solutions of the Pedersen Process: The Effect of Carbonate Content
Author(s) -
Danai Marinos,
Michail Vafeias,
Dimitris Sparis,
Dimitrios Kotsanis,
Efthymios Balomenos,
D. Panias
Publication year - 2021
Publication title -
journal of sustainable metallurgy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.548
H-Index - 22
eISSN - 2199-3831
pISSN - 2199-3823
DOI - 10.1007/s40831-021-00403-w
Subject(s) - carbonation , gibbsite , sodium aluminate , carbonate , leaching (pedology) , precipitation , aluminate , sodium carbonate , hydrate , chemical engineering , mineralogy , materials science , chemistry , sodium , metallurgy , geology , cement , soil science , kaolinite , aluminium , composite material , physics , organic chemistry , meteorology , engineering , soil water
Leaching experiments were performed in calcium aluminate slag with a high-sodium carbonate adaptation of the Pedersen process. A theoretical thermodynamic study of the pregnant leaching solution was conducted to specify the thermodynamically favored species that exist within. Using the HSC 9.0 software, a carbonation process simulation (neutralization of the aluminate solution with CO 2 gas) was simulated. Laboratory carbonation experiments were conducted to verify the theoretical predictions. According to the thermodynamic study, at temperatures below 50 °C gibbsite precipitates in the first stages of carbonation and then is transformed to dawsonite. Temperatures over 65 °C favor the direct precipitation of dawsonite. The same route (thermodynamic analysis, carbonation simulation, and experimental verification) was followed by a synthetic solution containing lower amount of sodium carbonate to prove that dawsonite precipitation occurred as a result of the high free carbonate content, to investigate the effect of temperature and to precipitate alumina hydrate phases. Graphical Abstract