新脱ガス法(真空吸引脱ガス法)による融体の高純度化に関する研究

提出了一种真空抽吸脱气方法（VSD法），并将其应用于金属液中形成气体的杂质的去除。通过可渗透气体而不渗透熔体的多孔隔板将熔体与外部分离，并将外部保持在降低的压力下。然后，形成气体的杂质在隔板-熔体界面处气化，形成的气体通过隔板被吸到外面。因此，从熔融金属中去除杂质的能力得到增强。在低浓度范围内，用多孔耐火材料管浸泡铁液进行了脱碳、脱氮实验。脱碳是由熔体中的碳与难熔氧化物（如Al_2O_3、SiO_2等）发生反应进行的。熔体中的碳浓度下降到几个ppm的非常低的值，而氧浓度保持在50ppm以下。Al_2O_3- sio_2管的脱碳速率比Al_2O_3管的脱碳速率高。多孔管透气性的增加使脱碳速率增大。结果表明，真空抽吸脱气法可以大大提高铁水的脱碳率。应用VSD法对铁水进行脱氮。同时脱碳可提高脱氮速率。多孔管-铁水界面脱氮的化学反应速率常数几乎等于以前在熔体表面吹气得到的速率常数。用VSD法研究了用石墨还原铜的过程。由于CO气体的吸入，脱氧速率降低，因此缺乏CO气泡的搅拌。然而，最小氧浓度降低到低于不使用VSD方法获得的值。VSD法对铁液和铝液脱氢也很有效。结果表明，铁液脱氢受液相和气相传质控制，铝液脱氢受液相传质控制。实际应用的测试无法进行，是未来研究的主题。少

A vacuum suction degassing method (VSD method) has been proposed and applied to remove gas-forming impurities in molten metal. The melt is separated from the outside by means of a porous partition wall permeable to gas and impermeable to the melt, and outside is kept at a reduced pressure. Then, the gas-forming impurities gasify at the partition wall-melt interface and the formed gas is sucked through the wall to the outside. Thus, the removal of the impurities from the molten metal is enhanced.Experiments of decarburization, denitrogenation of molten iron have been performed in the ranges of low concentrations by immersing a porous refractory tube into the melt. The decarburization proceeds by a reaction between the carbon in the melt and the refractory oxide, such as Al_2O_3, SiO_2, etc. The carbon concentration of the melt decreases down to a very low value of a few ppm, while the oxygen concentration is kept below 50ppm. The rate of decarburization with an Al_2O_3-SiO_2 tube is muc … More h higher than that with an Al_2O_3 tube. In crease in gas permeability of the porous tube makes the decarburization rate larger. It is shown that the vacuum suction degassing method can greatly increase the decarburization rate of molten iron. The VSD method has been applied to denitrogenate molten iron. The rate of denitrogenation increases by the simultaneous decarburization. The chemical reaction rate constant for the denitrogenation at the porous tube-molten iron interface is almost equal to that obtained previously by gas blowing onto the melt surface.The deoxidation of molten copper with graphite has been studied by applying the VSD method. The deoxidation rate decreases due to suction of CO gas and hence lack of stirring by the CO bubbles. However, the minimum oxygen concentration decreases to a lower value than that obtained without using the VSD method.The VSD method is also shown to be effective in dehydrogenating molten iron and molten aluminum. It is found that the dehydrogenation of molten iron is controlled by the liquid phase and the gas phase mass transfer and that of molten aluminum by the liquid phase mass transfer.A test of practical application could not have been carried out and is the subject of a future study. Less