| 摘要 |
<p>PURPOSE:To obtain high purity Ga crystals with high refining efficiency, at the time of crystallizing a Ga molten metal by pulling Ga crystals upward while they are rotated, by forming an acid soln. layer on the surface of the Ga molten metal. CONSTITUTION:At the time of crystallizing a crude Ga molten metal, e.g., recovered from scrap by a rotation upward pulling method, the surface of the Ga molten metal existing as a mother liquor is coated with an acid soln. layer. As the acid soln., the water soln. contg. strong acid such as hydrochloric acid, sulfuric acid, perchloric acid and formic acid is preferably used. Furthermore, the acid concn. of the acid soln. is generally regulated to the range of 0.05 to 5 N, preferably 0.1 to 1 N. Then, the acid soln. is brought into contact with the Ga molten metal as a mother liquor, by which impurity metals included in the Ga molten metal are melted away into the acid soln. Simultaneously, the impurity metals are oxidized by dissolved oxygen in the acid soln. and are precipitated as a solid matter. As the result, the sticking of Ga microcrystals including impurity metals into the surface of a crystal bar to be pulled up is prevented, by which high purity metallic Ga can be pulled up.</p> |
