Titanium is a metal that is not yet implemented in Vintage Story (as of version 1.16). However, its ore ilmenite is used in the steel making process.
Currently, pure titanium metal cannot be created.
The ore of titanium is ilmenite. Ilmenite can be found in igneous rock layers, as well as in phyllite, slate and kimberlite.
Ilmenite is currently only used in its crushed form to produce tier 3 refractory bricks. Ilmenite chunks (not nuggets) may be crushed in a pulverizer with a Tier 4 or better pounding cap. Crushed ilmenite may then be mixed with fire clay, crushed bauxite, crushed quartz, and crushed olivine to form a refractory brick.