On-line analyzer for Ni-Zn alloy electroplating bath

• Published in: ISIJ international Vol. 29; no. 10; pp. 887 - 893
• Main Authors: Matsumoto, Yoshiro, Fujino, Nobukatsu, Shibuya, Atsuyoshi, Nakahara, Hideyoku, Nakase, Ikuo, Koizumi, Akihiro
• Format: Journal Article
• Language: English
• Published: 01.01.1989
• ISSN: 0915-1559
• DOI: 10.2355/isijinternational.29.887

In the production of Ni--Zn alloy electroplated steel sheets, the concentrations of Ni exp 2+ and Zn exp 2+ ions in the plating bath are necessary to be controlled. An automatic on-line analyzer has been developed for the process control. The on-line analysis system consists of a sampling system and an energy-dispersive X-ray fluorescence analyzer. The plating process solution is continuously supplied to the X-ray fluorescence analyzer through the sampling system from the plating trays. The concentrations of the Ni exp 2+ and Zn exp 2+ ions are determined from the intensities of Ni, Zn, Fe and sulphur fluorescent lines. The intensities of the S and Fe lines are measured for interelement correction. The intensity of the S line is easily measured after a path in air with the energy-dispersive X-ray spectrometer. The S line is excited by Cr and the Ni, Zn and Fe lines are by tungsten X-ray source, for obtaining a higher excitation efficiency. The analysis can be completed within 8 min. The analytical accuracies on the production line were 0.77 g/l for Ni exp 2+ and 0.48 g/l for Zn exp 2+ ion. 12 ref.--AA