Their
production is based on the reduction of iron oxides, the removal of
impurities and the addition of carbon and alloying metals such as Cr, Mn
and Ni Some compounds are manufactured for special purposes such as
TiO for the pigment industry and MnO2 for use in dry battery cells The
battery industry also requires Zn and Ni/Cd The elements of Group 11
are still worthy of being called the coinage metals, although Ag and Au
Name a member of the lanthanoid series which is well known
to exhibit +4 oxidation state