In the first stage of cyanide destruction for a copper plating rinse, the desired ORP setpoint should exceed what level?

In the first stage of cyanide destruction for a copper plating rinse, setting the desired oxidation-reduction potential (ORP) at 650mV is essential for effectively initiating the process of detoxifying cyanide. At this ORP level, sufficient oxidizing conditions are created to facilitate the conversion of cyanide ions into less harmful compounds.

An ORP of 650mV is generally recognized as a threshold that ensures adequate oxidation occurs, which is crucial in breaking down the cyanide effectively without compromising the integrity of the copper rinse solution or generating hazardous byproducts. This specific setpoint balances the need for effective treatment while avoiding potential adverse effects that can occur if the potential is set too high, which may lead to the formation of unwanted reactions or byproducts.

In contrast, values exceeding 650mV, such as 700mV or 750mV, tend to introduce a risk of over-oxidation, which may not provide any additional benefits to the cyanide destruction process while possibly leading to complications. It's vital to maintain the ORP within a range that promotes effective cyanide elimination while ensuring the process remains safe and controlled. Thus, establishing the initial ORP setpoint at 650mV is optimal for starting the cyanide