(under subclass 592) Products or processes wherein the metal is iron.
(1) Note. Ferriferous oxide (Fe3O4) may be merely a mixture of one part ferrous oxide (FeO) and one part ferricoxide (Fe2O3). Such a compound (Fe3O4) will be considered a compound for this Class 423 and will be classified in this subclass 632 and not in subclass 633 below. However, if the ratio of the FeO to the Fe2O3 is other than one-to-one (stoichiometric) or if a range is given, the product will be considered a composition and the patent will be classified in the appropriate composition class.
SEE OR SEARCH THIS CLASS, SUBCLASS:
151, for making magnetic Fe3O4 from impure starting materials such as ores or waste products.
SEE OR SEARCH CLASS
106, Compositions: Coating or Plastic,
456+, for a pigment composition which may comprise a mixture of ferrous and ferric oxides, in which the oxides are present in other than one-to-one proportion (stoichlometric) or in which mixture one of the oxide is stated to be present in a range of parts (between 1 part and 3 parts, etc.). 252, Compositions,
62.51+, especially 62.56, for a magnetic composition, which may comprise a mixture of ferrous and ferric oxides, in which the oxides are present in other than a one-to - one proportion (stoichiometric) or in which in the mixture one of the oxides is stated to be present in a range of parts (between 1 part and 3 parts, etc).
501, Compositions: Ceramic,
94+, for ceramic refractory compositions which may comprise a mixture of ferrous and ferric oxides, in which the oxides are present in other than a one-to-one proportion (stoichiometric) or in which mixture one of the oxides is stated to be present in a range of parts (between 1 part and 3 parts, etc.).
502, Catalyst, Solid Sorbent, or Support Therefor: Product or Process of Making,
