Vacated county hospital disposing of nickel and aluminium in rings (8)
I believe the answer is:
cyclical
'vacated county hospital' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives occasionally define each other.
'disposing of nickel and aluminium in rings' is the wordplay.
I cannot really understand how this works, but
'aluminium' could be 'al' (chemical symbol) and 'al' is present in the answer.
The remaining letters 'cyclic' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for cyclical that I've seen before include "Recurring in series" , "Recurrent (as in chain of events)" , "Regularly recurring sequence of events" , "Regularly repeating" .)