Abstract: The present invention provides a method for preparing metallic titanium by electrolyzing molten salt with titanium circulation. The method mainly comprises reducing titanium tetrachloride (TiCl4) to at least one of titanium trichloride (TiCl3) and titanium dichloride (TiCl2) in chloride molten salt by metallic titanium (Ti), and electrolyzing the at least one of TiCl3 and TiCl2 in the chloride molten salt to form metallic titanium. According to the method for preparing metallic titanium of the present invention, TiCl2, and/or TiCl3 are prepared and electrolyzed continuously without changing the surrounding medium, thereby simplifying process flow, reducing power consumption, and realizing industrialization.

Abstract: The present invention discloses a heat treatment method of steel rail, comprising the steps of: (1) keeping the rolled hot steel rail running continuously, and performing hot straightening process for it; (2) performing first heat treatment process for the rolled hot steel rail after the hot straightening process, i.e., forced cooling the rail head and the rail base of the steel rail in a jetting air cooling manner, and (3) performing second heat treatment process for the steel rail after the first heat treatment process, i.e., heating the rail head of the steel rail to a temperature of 850˜950° C., and then forced cooling the rail head of the steel rail in a jetting air cooling manner to a temperature that is close to the temperature of the rail base of the steel rail.