Лако-красочные материалы — производство

Metallic iron pigments are commercially produced by the reduction ofacicular (needle­shaped) iron compounds [5.21]. As in the production of magnetic iron oxide pig­ments, the starting materials are iron oxide hydroxides (see Section 3.1.1) or iron oxalates, which are reduced to iron in a stream of hydrogen either directly or via oxidic intermediates.

Due to their high specific surface area, metallic pigments are pyrophoric, so that passivation is necessary. This can be achieved by slow, controlled oxidation of the particle surface [5.22].