Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA781797A
Inventor
R. Martin John
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Calumet and Hecla Inc
Original Assignee
Calumet and Hecla Inc
Publication date
Application grantedgrantedCritical
Publication of CA781797ApublicationCriticalpatent/CA781797A/en