CPC Subgroup
C22B 3/20 Treatment or purification of solutions, e.g. obtained by leaching (C22B3/18 takes precedence)
Full Title
Extraction of metal compounds from ores or concentrates by wet processes > Treatment or purification of solutions, e.g. obtained by leaching (C22B3/18 takes precedence)
5 direct subcodes
Child Classifications
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- C22B 3/22 by physical processes, e.g. by filtration, by magnetic means (treatment or purification of solutions by liquid-liquid extraction C22B3/26)
- C22B 3/26 by liquid-liquid extraction using organic compounds
- C22B 3/42 by ion-exchange extraction
- C22B 3/44 by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42)
Top Applicants
Top 10 applicants by patent filingsfor class C22, 2013–2023, worldwide · Source: EPO PATSTAT
- JFE STEEL JP 7,620
- NIPPON STEEL CORPORATION JP 5,769
- POSCO (POHANG IRON AND STEEL COMPANY) KR 4,523
- JFE STEEL 3,080
- NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,999
- ARCELORMITTAL LU 2,962
- CENTRAL SOUTH UNIVERSITY 2,431
- KOBE STEEL JP 2,100
- CHINESE ACADEMY OF SCIENCES 2,052
- MITSUBISHI MATERIALS CORPORATION JP 1,405