FACTORS INFLUENCING THE CHOICE OF EXTRACTION PROCESS

The type of process used commercially for any particular element depends on a number of factors.
 

• Is the element unreactive enough to exist in the free state?

• Are any of its compounds unstable to heat?

• Does the element occur as sulphide ores, which can be roasted or oxide ores, which can be reduced using carbon, is the cheapest whilst the use of Mg, AI and Na as reducing agents is more expensive.

• If all other methods fail, electrolysis usually works for ionic materials, but is expensive. If the element is stable in water, electrolyzing aqueous solution is cheaper than using fused melts.