Vocally object to coal being obtained thus? (5)
I believe the answer is:
mined
'coal being obtained thus?' is the definition.
(coal is mined)
'vocally object to' is the wordplay.
'vocally' indicates a 'sounds like' (homophone) clue.
'object to' becomes 'mind' (I've seen this before).
'mind' is a homophone of 'MINED'.
(Other definitions for mined that I've seen before include "laid eggs" , "Quarried" , "Sought diamonds?" , "Dug from pit" , "Excavated as for coal or diamonds" .)