C01F 11/468
Purification of calcium sulfates
Official title: {Purification of calcium sulfates}
C01F11/468 (Purification of calcium sulfates) appears on 48 US grants and 44 published applications in this corpus.
Search patents in C01F- Granted patents
- 48
- Published applications
- 44
- Assignees
- 46
- Inventors
- 145
- Latest grant
- 28 Apr 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 0 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 1 | 0 |
| 1983 | 2 | 0 |
| 1984 | 2 | 0 |
| 1985 | 0 | 0 |
| 1986 | 2 | 0 |
| 1987 | 0 | 0 |
| 1988 | 0 | 0 |
| 1989 | 0 | 0 |
| 1990 | 1 | 0 |
| 1991 | 0 | 0 |
| 1992 | 1 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 0 | 0 |
| 1996 | 1 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 1 |
| 2003 | 2 | 1 |
| 2004 | 2 | 0 |
| 2005 | 0 | 0 |
| 2006 | 1 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 1 |
| 2011 | 0 | 1 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 1 | 1 |
| 2015 | 1 | 1 |
| 2016 | 0 | 1 |
| 2017 | 1 | 6 |
| 2018 | 3 | 7 |
| 2019 | 7 | 2 |
| 2020 | 0 | 1 |
| 2021 | 1 | 5 |
| 2022 | 3 | 0 |
| 2023 | 4 | 7 |
| 2024 | 1 | 2 |
| 2025 | 3 | 3 |
| 2026 | 5 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Integrated method for the commercial and industrial utilisation of calcium sulphate whilst obtaining rare earth elements from the production of phosphoric acid28 Apr 2026US 12,612,309 B2thyssenkrupp AG
- Method for producing phosphoric acid and calcium sulphate quality suitable for a clinker process for the commercial and industrial utilization of calcium sulphate24 Mar 2026US 12,583,747 B2thyssenkrupp AG
- Sustainable hybrid composite made from biodegradable polymer reinforced with Extracted Powder Compound from Reject Brine (EPC-RB)24 Mar 2026US 12,583,772 B2United Arab Emirates University
- Method for compression of aqueous slurry containing solid foreign matter and paper dust, and treatment method of waste gypsum board24 Feb 2026US 12,559,380 B2Tokuyama Corporation
- Method of preparing ferric phosphate from iron-containing waste3 Feb 2026US 12,540,077 B2Guizhou Chanhen Chemical Corporation
- Method for comprehensive utilization of ulexite ore resources3 Sep 2026US 2026/0257927 A1Fujian Jungie New Material Technology Co., Ltd.
- Method of management of fly ashes from the combustion of petroleum products27 Aug 2026US 2026/0250488 A1RE-Solve Sp. z.o.o.
- Method and system for extraction of minerals based on divalent cations from brine8 Jan 2026US 2026/0008014 A1Saudi Water Authority
- Method for manufacturing sodium bicarbonate and gypsum using sodium sulfate1 Jan 2026US 2026/0001773 A1Research Institute of Industrial Science & Technology
- Sustainable hybrid composite made from biodegradable polymer reinforced with extracted powder compound from reject brine (epc-rb)2 Oct 2025US 2025/0304475 A1United Arab Emirates University
Most cited
By later US patents
- Method for the treatment of phosphogypsum12US 3,951,675 ACentre d'Etudes et de Recherches des Phosphates Mineraux Cerphos · 1976
- Method of treatment of sludge from a flue gas desulfurization plant11US 4,627,970 AGottfried Bischoff Bau Kompl. Gasreinigungsund Wasserruckkuhlanlagen GmbH & Co. · 1986
- Phosphohemihydrate process for purification of gypsum10US 4,424,196 AUnited States Gypsum Company · 1984
- Method for solidifying waste slime suspensions8US 4,457,781 AUnited States Gypsum Company · 1984
- Fluorogypsum waste solidification material7US 4,935,211 A1990