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PCE
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CPC Subgroup
C22B 3/44

by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42)

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) > by chemical processes (treatment or purification of solutions by liquid-liquid extraction C22B3/26, by ion-exchange extraction C22B3/42)

1 direct subcode

Child Classifications

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  • C22B 3/46 by substitution, e.g. by cementation

Top Applicants

Top 10 applicants by patent filingsfor class C22, 2013–2023, worldwide · Source: EPO PATSTAT

  1. JFE STEEL JP 7,620
  2. NIPPON STEEL CORPORATION JP 5,769
  3. POSCO (POHANG IRON AND STEEL COMPANY) KR 4,523
  4. JFE STEEL 3,080
  5. NSSMC (NIPPON STEEL & SUMITOMO METAL) JP 2,999
  6. ARCELORMITTAL LU 2,962
  7. CENTRAL SOUTH UNIVERSITY 2,431
  8. KOBE STEEL JP 2,100
  9. CHINESE ACADEMY OF SCIENCES 2,052
  10. MITSUBISHI MATERIALS CORPORATION JP 1,405