Skip to content
PCE
Search Classifications
Search for IPC and CPC classification codes or keywords
IPC Main Group
C21B 5/00

Making pig-iron in the blast furnace

Introduced: September 1968

Last revised: January 2006

Classification Context

Section:
CHEMISTRY; METALLURGY
Class:
METALLURGY OF IRON
Subclass:
MANUFACTURE OF IRON OR STEEL

Related Keywords

production of pig IRONtreatment of SLAG in iron production

3 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open

  • C21B 5/02 Making special pig-iron, e.g. by applying additives, e.g. oxides of other metals
  • C21B 5/04 Making slag of special composition
  • C21B 5/06 using top gas in the blast furnace process

Top Applicants

Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT

  1. JFE STEEL JP 7,470
  2. POSCO (POHANG IRON AND STEEL COMPANY) KR 4,615
  3. JFE STEEL 4,538
  4. NIPPON STEEL CORPORATION JP 4,536
  5. ARCELORMITTAL LU 2,597
  6. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,241
  7. ANGANG STEEL COMPANY 2,126
  8. NSSMC (NIPPON STEEL & SUMITOMO METAL) 1,783
  9. BAOSHAN IRON & STEEL COMPANY 1,620
  10. HYUNDAI STEEL COMPANY KR 1,545