C01B 25/226
Hemihydrate process
C01B25/226 (Hemihydrate process) appears on 24 US grants and 1 published applications in this corpus.
Search patents in C01B- Granted patents
- 24
- Published applications
- 1
- Assignees
- 15
- Inventors
- 37
- Latest grant
- 9 Aug 2022
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 1 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 3 | 0 |
| 1981 | 6 | 0 |
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 2 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 1 | 0 |
| 1988 | 1 | 0 |
| 1989 | 2 | 0 |
| 1990 | 0 | 0 |
| 1991 | 1 | 0 |
| 1992 | 2 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 0 | 0 |
| 1999 | 0 | 0 |
| 2000 | 0 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 0 |
| 2006 | 0 | 0 |
| 2007 | 0 | 0 |
| 2008 | 0 | 0 |
| 2009 | 0 | 0 |
| 2010 | 0 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 0 |
| 2018 | 0 | 0 |
| 2019 | 0 | 0 |
| 2020 | 0 | 1 |
| 2021 | 0 | 0 |
| 2022 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Method for etching a phosphate source using acid9 Aug 2022US 11,407,640 B2Prayon Technologies
- Apparatus for producing phosphoric acid from phosphate ore3 Mar 1992US 5,093,088 APotash Corporation of Saskatchewan
- Recovery and utilization of gypstack leachate in hemihydrate phosphoric acid process28 Jan 1992US 5,084,261 AOccidental Chemical Corporation
- Crystal modification in wet process phosphoric acid production23 Apr 1991US 5,009,873 ANalco Chemical Company
- Method for producing phosphoric acid from phosphate ore9 May 1989US 4,828,811 APotash Corporation of Saskatchewan
Most cited
By later US patents
- Method of preventing gypsum scale formation in phosphoric acid plant filters12US 3,972,981 AFisons Limited · 1976
- Process for reducing formation of gypsum scale durng the washing of calcium sulphate hemihydrate crystals12US 4,049,774 AFisons Limited · 1977
- Continuous process for preparing phosphoric acid and calcium sulphate11US 4,777,027 APrayon Developpment, Societe Anonyme · 1988
- Hemihydrate type phosphoric acid process9US 4,196,172 AOccidental Petroleum Corporation · 1980
- Method for the wet process manufacture of phosphoric acid9US 4,501,724 AGoers Associates Inc. · 1985