C
SECTION C — CHEMISTRY AND METALLURGY
  
METALLURGY
 C22
METALLURGY (of iron C21); FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR OF NON-FERROUS METALS
 C22B
PRODUCTION AND REFINING OF METALS (electrothermic C22D); PRETREATMENT OF RAW MATERIALS
 C22B

Note(s)

In this sub-class, groups for obtaining metals include obtaining the metals by non-metallurgical processes, and obtaining metal compounds by metallurgical processes. Thus, for example, group C22B 11/00 covers the production of silver by reduction of ammoniacal silver oxide in solution, and group C22B 17/00 includes the production of cadmium oxide by a metallurgical process. Furthermore, although compounds of arsenic and antimony are classified in C01B, production of the elements themselves is included in C22B, as well as the production of their compounds by metallurgical processes.


 C22C
NON-FERROUS ALLOYS (heat treatment thereof C22F); FERROUS ALLOYS; TREATMENT THEREOF

 C22D
ELECTROLYTIC AND ELECTROTHERMIC PRODUCTION AND REFINING OF METALS

 C22F
CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS