Titanium Smelting

When smelting titanium, there are complicated steps to go through. The ilmenite into titanium tetrachloride, and then put into a sealed stainless steel tank, filled with argon, so that they react with the metal magnesium, you get "titanium sponge". But this porous "titanium sponge" can not be used directly, but also must be melted into liquid in the furnace, in order to cast into ingots. However, it is very difficult to manufacture this kind of electric furnace. In addition to pumping out the air in the furnace, it is also necessary to find a crucible that can hold liquid titanium. This was because refractory materials generally contain oxides, the oxygen of which is taken away by liquid titanium. Later, the "water-cooled copper crucible" furnace was invented. In these furnaces, only a central part of the furnace is hot, the rest of the furnace is cold. Titanium is melted in the furnace and flows onto the walls of the water-cooled copper crucible, where it is immediately condensed into ingots. It has been possible to produce titanium blocks weighing several tons in this way, but at a high cost.