Assessing the Role of Smelter Grade Alumina Porosity in the HF Scrubbing Mechanism

The Pivotal Role of Alumina Pore Structure in HF Capture and Fluoride Return in Aluminum Reduction

“…22 This may indicate that there may be two mechanisms operating. However, given the range of materials we have considered both here and in previous studies, [11][12][13][23][24][25] and the fact that models such as those shown in Fig. 5 do not, when examined in detail, demonstrate the sorts of shifts that Dando and Lindsay observe, 22 this suggests that it is also possible that the PSD changes they observe may be associated with a different deposition product.…”

“…11,12 SSA decreases are observed with preferential losses from the smaller pores (typically < 20 nm). 11,12 From this, it is possible to develop a model describing PSD changes and benchmark this against aluminas dosed under both laboratory and industrial conditions. PSDs effectively provide the total surface area of a pore at a particular pore diameter D p .…”

“…However, the blended sample will have a much higher proportion of the porosity associated with these small pores. Our alumina group within the Light Metals Research Centre has recently performed a number of studies examining the role of pore size on HF capture efficiency 11,12 and its role in fluoride return to the reduction cells. 13 In this work, we review key elements of these studies, and address the overall implications when these results are taken together.…”