| 摘要 |
<p>A process for treating worn linings by silicopyrohydrolysis, the linings originating especially from Hall-Héroult electrolysis cells and consisting of a mixture of carbon-containing products and silico- aluminous products impregnated with fluorine-containing inorganic compounds especially of sodium, calcium and aluminium, consisting in converting these linings by treatment at a temperature of at least 1000 DEG C by means of an oxidising gas, water vapour and silica, - firstly in a gas phase containing most of the fluorine, in the form of hydrofluoric acid, and of the carbon, in the form of carbon dioxide and monoxide, - secondly, in an at least partially liquid phase containing the silicon, the aluminium, the calcium and the sodium and most of the other impurities (iron, titanium, heavy metals etc.) in the form of oxygen-containing compounds, essentially in the form of silicates. The process can be used in a single stage or in two stages in two successive reactors.</p> |
