We don't have synonyms for delving yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are deleing, delvin and helving.
(n) :
Alternative form of dilving. [(obsolete, mining) The shaking of tin ore in a sieve held underwater so that the waste flows out, leaving the tin behind.]
(n) :
Alternative form of dilving. [(obsolete, mining) The shaking of tin ore in a sieve held underwater so that the waste flows out, leaving the tin behind.]