In the metals and alloys obtained by melting, due to the selection of materials used, in addition to the necessary metal components, harmful or unnecessary metals and non-metal components are often contained. As we all know, the impurities contained in molten metal such as sulfur, oxygen, hydrogen, nitrogen, etc. will greatly affect the quality of the final product. This is why the secondary refining process is often carried out, which performs additional purification of the molten metal taken from the furnace.
A refining method is provided, which removes even trace amounts of harmful and unnecessary metal and non-metal components (elements) through refining in an inert atmosphere, accompanied by electrode heating and forced stirring.
In order to achieve the goal, the refining step includes the following steps:
- Fill the molten metal to be refined with refining flux into a refining vessel equipped with at least a heating electrode and an inert gas blowing device;
- The first refining process, which reacts the molten metal with the flux by heating the molten metal with a heating electrode, while maintaining the interior of the refining container under an inert gas atmosphere;
- A second refining process, which includes tilting the refining vessel to immerse the blowing tube of the inert gas blowing device into the molten metal, and blowing inert gas into it;
- The molten metal thus refined is taken out from the refining vessel.
In order to perform such a refining process, a tiltable refining vessel is used, which is suitable for filling the molten metal and flux to be refined, and an appropriate number of electrodes are arranged on the upper part of the vessel. The refining vessel is used for heating the molten metal contained in the refining vessel, and an inert gas blowing device. The blowing nozzle is not immersed in the molten metal when the molten metal is charged, but is immersed only when the vessel is tilted for the purpose of blowing.