Development of a Miniature Spectrometer Based on Ultraviolet-Visible Spectroscopy for Quantitative Analysis of Copper and Cobalt

Abstract

Considering the requirements of miniaturization, integration, digitization and high precision of online detection instrument, a miniature spectrometer based on ultraviolet-visible spectroscopy is developed for the on-line detection of copper and cobalt in the purification process of zinc hydrometallurgy. Firstly, the serial port protocol of spectrometer is developed to realize remote online acquisition of spectral signal. Then, a wavelet threshold denoising method is proposed to eliminate the noise interference caused by the spectrometer and the circuit system. Next, based on the invariance of the dual-wavelength light intensity ratio in the spectral detection, an error correction algorithm is proposed to dynamically eliminate the systematic measurement error caused by light source fluctuations. Finally, the partial least squares method is used to detect the concentration of copper and cobalt, and the detection performance of online miniature spectrometer is compared with that of dual-beam spectrometer. The results show that the developed online analysis instrument can detect polymetal ions in less than 5 min, the average relative error is less than 10%, and the detection accuracy is higher than 94.74%, which is suitable for the online acquisition and analysis of polymetal ions in high concentration zinc solution.

Keywords

• Ultraviolet-visible spectroscopy
• zinc hydrometallurgy
• miniature spectrometer
• wavelet threshold method
• on-line detection
• error correction algorithm