IPC Main Group
C21B 7/00 Blast furnaces
Introduced: September 1968
Last revised: January 2006
Classification Context
- Section:
- CHEMISTRY; METALLURGY
- Class:
- METALLURGY OF IRON
- Subclass:
- MANUFACTURE OF IRON OR STEEL
Filing statistics
IPC C21B 7/00 belongs to the parent subclass C21B, which recorded 31,098 patent applications worldwide between 2013 and 2023. Annual filings grew from 2,313 in 2013 to 3,647 in 2023 (+58%), peaking at 3,970 applications in 2022. The most active applicants in class C21 are JFE STEEL (7,470 applications), POSCO (POHANG IRON AND STEEL COMPANY) (4,615 applications) and JFE STEEL (4,538 applications).
Source: EPO PATSTAT, worldwide filings
Related Keywords
BLAST furnacesblast FURNACES
10 direct subcodes
Child Classifications
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- C21B 7/02 Internal forms
- C21B 7/04 with special refractories
- C21B 7/08 Top armourings
- C21B 7/1 Cooling; Devices therefor
- C21B 7/12 Opening or sealing the tap holes
- C21B 7/14 Discharging devices, e.g. for slag
- C21B 7/16 Tuyères
- C21B 7/18 Bell-and-hopper arrangements
- C21B 7/22 Dust arresters
- C21B 7/24 Test rods or other checking devices
Top Applicants
Top 10 applicants by patent filingsfor class C21, 2013–2023, worldwide · Source: EPO PATSTAT
- JFE STEEL JP 7,470
- POSCO (POHANG IRON AND STEEL COMPANY) KR 4,615
- JFE STEEL 4,538
- NIPPON STEEL CORPORATION JP 4,536
- ARCELORMITTAL LU 2,597
- NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,241
- ANGANG STEEL COMPANY 2,126
- NSSMC (NIPPON STEEL & SUMITOMO METAL) 1,783
- BAOSHAN IRON & STEEL COMPANY 1,620
- HYUNDAI STEEL COMPANY KR 1,545