| 摘要 |
<p>A bottom lining for steel-cased electrolysis cells, especially aluminium production and refining pots, comprises a monolithic rammed lining of an alumina-rich fine powder product which is prepared from aluminium industry drosses and salt slags and which contains (on dry wt. basis) 40-90% Al2O3, 0.1-25% AlN, 4-20% MgO, 0.5-15% SiO2, 0.1-15% CaO, 0.1-10% metallic Al, 0.1-10% metallic Si, 0.1-5% Fe2O3, NOTGREATER 5% C, NOTGREATER 5% F, 0.1-5% Na2O, 0.1-2% K2O, 0.1-2% TiO2 and NOTGREATER 5% others, the loss on ignition being NOTGREATER 10%. Also claimed is production of the above bottom lining, in which (a) the above fine powder product is produced by grinding, leaching, filtration and/or heat treatment of aluminium industry drosses and salt slags and is then pelleted, briquetted or extruded to moulded bodies; and (b) the bodies are dried or calcined to less than 5% loss on ignition/moisture content, filled into the electrolysis cell and compacted by ramming or vibration. Further claimed is a method of process ing the above bottom lining, after use in aluminium electrolysis cells, by breaking up the cell bottom lining and subjecting it to grinding, leaching, filtration, drying, calcination and/or sintering for recovering a fine powder product in which the MgO is mineralogically combined as spinel.</p> |
