Determination of Cuprous Ion in the Presence of Ferrous Ion

Significance of the Topic

Electrochemical copper leaching processes generate solutions containing both cuprous and ferrous ions. Precise measurement of cuprous ion is vital for process control, product quality and efficient metal recovery. Conventional redox methods may suffer interferences from iron, making selective quantification of Cu+ essential in hydrometallurgical operations.

Aims and Study Overview

This application note describes a thermometric titration technique for determining cuprous ion in the presence of ferrous ion in industrial copper leach feed solutions. The approach exploits sequential exothermic endpoints corresponding to oxidation of Fe2+ followed by Cu+ by standardized dichromate. The cuprous concentration is calculated from the difference between the two thermal endpoints.

Methodology and Instrumentation

The procedure uses a thermometric titrator configured with the following parameters:

• Data acquisition rate: 5 readings per second
• Titrant delivery rate: 1 mL per minute
• Number of exothermic endpoints: 2
• Data smoothing factor: 40

Reagents include 0.1 mol per liter potassium dichromate and 10 percent sulfuric acid. A diluted aliquot of 20 mL leach solution and 10 mL acid is brought to 200 mL total volume. A 15 mL sample is titrated to the second thermal endpoint, after addition of further acid.

Main Results and Discussion

Analysis of an actual electrochemical leach solution yielded a mean cuprous ion concentration of 205.7 plus or minus 0.1 grams per liter (n equals 5). While the ferrous endpoint displayed variability, the cuprous measurement was remarkably consistent. The titration plot shows solution temperature, first derivative and second derivative curves, with distinct inflection points marking Fe2 plus and Cu plus oxidation.

Benefits and Practical Applications

• Selective quantification of Cu+ in the presence of Fe2+ without extensive sample pretreatment
• Rapid analysis with automated endpoint detection enhances throughput
• High precision supports real time monitoring and quality control in copper hydrometallurgy

Future Trends and Possibilities

Further integration of thermometric titration with digital control and data analytics will improve process automation. Expansion of this technique could address other redox systems in mining, environmental monitoring and industrial wastewater treatment. Miniaturized sensor designs and advanced endpoint algorithms may extend application range and sensitivity.

Conclusion

The described thermometric titration method provides a robust and precise approach for determining cuprous ion in complex leach matrices containing ferrous ion. By leveraging dual exothermic endpoints, it overcomes common interferences and delivers reliable results suitable for industrial quality assurance.

References

• Thermo Titration Application Note No H-005 Determination of Cuprous Ion in the Presence of Ferrous Ion