Laterite mineral ores are primarily composed of limonite, (Fe, Ni)O(OH), and garnierite, (Ni, Mg)3Si2O5(OH). The sulfide deposits are composed primarily of pentlandite, (Ni,Fe)9S8. Nickel is isolated using the principles of extractive metallurgy. During this isolation process, the nickel ore is heated and then undergoes reduction; this heating and reduction step results in a composition of nickel that is approximately ¾ pure. To isolate the nickel further for almost 100% purity, the Mond process is used.
During the Mond process, nickel is combined with carbon monoxide and heated to approximately 122 °F. The result of the reaction causes a volatile nickel carbonyl to form, and other impurities are left in a solid state. The nickel carbonyl is then brought into a chamber where it is exposed to high temperatures along with nickel spheres which are constantly moving; over time, the nickel carbonyl disintegrates and pure nickel is deposited into the nickel spheres forming solid nickel pellets.
