The raw material of titanium metal is mainly rutile, which contains more than 96% TiO2. Countries that lack rutile ore, such as the Soviet Union, use "high titanium slag" made of ilmenite, which contains about 290 percent TiO. Due to the rising price of natural rutile and decreasing reserves, all countries tend to use ilmenite to make titanic-rich materials, namely high titanium slag and artificial rutile. Titanium was discovered in 1791, and the first pure titanium was made in 1910, more than a century later. The reason is that titanium is very active at high temperature, and it is easy to combine with oxygen, nitrogen, carbon and other elements, to extract pure titanium needs very harsh conditions.
When smelting titanium, there are complicated steps. Turn ilmenite into titanium tetrachloride and put it in a sealed stainless steel tank filled with argon to react with magnesium to get "titanium sponge". The porous "titanium sponge" cannot be used directly, but must be melted into a liquid in an electric furnace to form the ingot. But making this kind of stove is not easy! In addition to the fact that the air had to be pumped out of the furnace, it was almost impossible to find a crucible to hold the liquid titanium, which was stripped of oxygen by the oxides that were commonly found in refractories. Later, people finally invented a "water-cooled copper crucible" electric furnace. Only a central part of the furnace is hot; the rest is cold. When the titanium is melted in the furnace, it flows onto the wall of a copper crucible cooled by water, and immediately condenses into titanium ingots. It has been possible to produce several tonnes of titanium in this way, but the cost is not to be imagined.