VERFAHREN ZUR REGENERATION EINES AMMONIAKALISCHEN AETZMITTELS SOWIE VORRICHTUNG ZUR DURCHFUEHRUNG DIESES VERFAHRENS

摘要

During the etching process, the metal etched off is deposited in the etching agent and must be removed in an electrolytic cell (11) to regenerate the etching agent. In an ammoniacal environment undesired nitrates are thereby formed. According to the invention, they are reduced by the addition of a reducing agent (26, 27, 28) to gaseous nitrogen, ammonia or other reaction products which are either volatile or present in the etching agent in any case. Suitable reducing agents are especially hydrazine, hydrazine compounds, formaldehyde or hydrogen.