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

提出了一种真空吸气脱气法(VSD法)，并将其应用于去除金属熔体中的成气杂质。熔体通过对气体渗透和对熔体不渗透的多孔隔壁从外部分离，并且外部保持在降低的压力下。然后，成气杂质在隔壁-熔体界面气化，形成的气体通过隔壁向外吸入。通过将多孔耐火管浸入熔体中，在低浓度范围内对铁水进行了脱碳、脱氮试验。脱碳是通过熔体中的碳与Al_2O_3、SiO_2等难熔氧化物的反应进行的，熔体中的碳浓度下降到很低的几个ppm，而氧浓度保持在50ppm以下。Al_2O_3-SiO_2管的脱碳速率为MUC…比Al_2O_3管更高的h。多孔管透气性的增加使脱碳率增大。结果表明，真空吸气脱气法可大大提高铁水的脱碳率。VSD法已应用于脱氮铁水。同时脱碳提高了脱氮速度。多孔管-铁水界面脱氮的化学反应速率常数与气体吹入熔体表面的反应速率常数基本相同。用VSD方法研究了石墨对铜熔体的脱氧作用。脱氧速率降低是由于CO气体被吸入，因此没有被CO气泡搅动。然而，最低氧浓度下降到低于未使用VSD法的值。VSD法对铁水和铝液的脱氢也是有效的。结果表明，铁水脱氢受液相传质和气相传质控制，铝液脱氢受液相传质控制，无法进行实际应用试验，有待进一步研究。较少

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