| 摘要 |
<p>When optimising the conventional purification methods, by gas, of aluminum in a molten state, a negative effect of the temperature has been revealed surprisingly when using a mixture of noble gases and carbon dioxyde. In the same way, it has been proved inadequate to use concentrations of carbon dioxyde higher than 10% in volume. It is therefor proposed to use, at a temperature comprised between 730 and 780 C a gaseous mixture comprised of at least an inert carrier gas and of 4 to 10% in volume of carbon dioxyde in a ratio of 0.4 to 1.0 N m3 per tonne of molten material. The method is also appropriate for continuous and discontinuous operation plants. In the first case an optimum effect of the stay time for the molten particules of three minutes should be provided, whereas a total time of one hour should be provided in the second case. This method allows, supposing a pseudo-l kinetic order, to reach a speed constant of 5.3 for sodium, 4.9 for lithium and 2.5 x 10-4 sec-1 for hydrogen, which makes the quality of the method vary with the composition of the alloy to be purified. </p> |
