论处 is a formal verb phrase used in legal and disciplinary contexts, meaning 'to decide on punishment' or 'to punish according to regulations'. It often appears in the pattern 以...论处, where 以 introduces the nature of the crime or violation (e.g., 以贪污罪论处 'to be punished for corruption'). This pattern is a fixed structure you should learn as a whole, as the verb itself is rarely used without it in modern Chinese.