C21B 13/10
In hearth-type furnaces
Official title: in hearth-type furnaces
C21B13/10 (In hearth-type furnaces) appears on 239 US grants and 222 published applications in this corpus.
Search patents in C21B- Granted patents
- 239
- Published applications
- 222
- Assignees
- 91
- Inventors
- 354
- Latest grant
- 12 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 2 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 3 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 2 | 0 |
| 1987 | 4 | 0 |
| 1988 | 1 | 0 |
| 1989 | 0 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 0 | 0 |
| 1993 | 1 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 2 | 0 |
| 1997 | 3 | 0 |
| 1998 | 5 | 0 |
| 1999 | 11 | 0 |
| 2000 | 14 | 0 |
| 2001 | 22 | 10 |
| 2002 | 17 | 16 |
| 2003 | 18 | 11 |
| 2004 | 9 | 13 |
| 2005 | 3 | 7 |
| 2006 | 4 | 15 |
| 2007 | 3 | 8 |
| 2008 | 6 | 4 |
| 2009 | 5 | 14 |
| 2010 | 10 | 20 |
| 2011 | 11 | 13 |
| 2012 | 17 | 22 |
| 2013 | 14 | 12 |
| 2014 | 8 | 4 |
| 2015 | 7 | 8 |
| 2016 | 3 | 6 |
| 2017 | 4 | 5 |
| 2018 | 7 | 4 |
| 2019 | 4 | 3 |
| 2020 | 4 | 3 |
| 2021 | 0 | 2 |
| 2022 | 3 | 4 |
| 2023 | 2 | 4 |
| 2024 | 2 | 6 |
| 2025 | 3 | 3 |
| 2026 | 1 | 5 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Process and system for the production of iron nuggets12 May 2026US 12,624,406 B2Carbontec Energy Corporation
- Method and device for producing direct reduced metal18 Feb 2025US 12,227,820 B2Greeniron H2 AB
- Method and device for producing direct reduced, carburized metal11 Feb 2025US 12,221,659 B2Greeniron H2 AB
- Method and device for producing direct reduced metal28 Jan 2025US 12,209,295 B2Greeniron H2 AB
- Method and device for producing direct reduced metal1 Oct 2024US 12,104,222 B2Greeniron H2 AB
- Biomass Direct Reduced Iron23 Jul 2026US 2026/0209873 A1Technological Resources Pty. Limited
- Method for producing metallic iron25 Jun 2026US 2026/0176707 A1Jef Steel Corporation
- A method for manufacturing pig iron in an electrical smelting furnace and associated furnace25 Jun 2026US 2026/0176708 A1
- Non-fired pellets for reduction and method for producing same12 Feb 2026US 2026/0043102 A1Jfe Steel Corporation
- Fired pellets for reduction and method for producing same29 Jan 2026US 2026/0028688 A1Jfe Steel Corporation
Most cited
By later US patents
- Method of producing iron using rotary hearth and apparatus73US 4,701,214 AMidrex International B.V. Rotterdam · 1987
- Method of producing a reduced metal, and traveling hearth furnace for producing same73US 6,126,718 AKawasaki Steel Corporation · 2000
- Method of direct iron-making / steel-making via gas or coal-based direct reduction and apparatus61US 6,648,942 B2Midrex International B.V. Rotterdam, Zurich Branch · 2003
- Direct reduction process in a rotary hearth furnace56US 5,186,741 AZia Patent Company · 1993
- Method for rapid reduction of iron oxide in a rotary hearth furnace53US 5,730,775 AMidrex International B.V. Rotterdam, Zurich Branch · 1998