Kroll process
The standard way of making titanium metal, replacing titanium's bond to chlorine with a bond to magnesium and then separating the result to leave spongy titanium metal.
Techniquement: The Kroll process is a batch pyrometallurgical reduction in which titanium tetrachloride vapour is reacted with liquid magnesium metal in a sealed, inert-atmosphere retort to yield titanium metal and magnesium chloride; the magnesium chloride is then drained and the residual magnesium recovered by vacuum distillation, leaving a porous titanium mass known as sponge. The process remains the predominant industrial route for primary titanium despite its batch nature and high energy demand, because titanium's extreme reactivity toward oxygen and nitrogen at elevated temperature makes continuous melting or aqueous routes difficult to implement at commercial scale. The magnesium chloride by-product is typically electrolysed to regenerate both magnesium and chlorine for recycle.
Processing
kimberlite
A rare type of rock that erupts violently from very deep in the Earth and sometimes brings diamonds with it, forming carrot-shaped pipes in the crust.
Techniquement: Kimberlite is a volatile-rich, ultramafic to potassic igneous rock emplaced from depths in excess of roughly 150 km, typically forming sub-vertical, roughly cylindrical bodies called pipes, dykes, and sills. It is the principal primary host for diamond, carrying xenoliths of mantle material including diamond-bearing peridotite. Kimberlite is often confused with lamproite, which can also be diamond-bearing; the distinction matters in exploration because the two rock types have different indicator-mineral suites and eruption styles.
Geology