Analytical Method to Monitor Industrial Pickling Baths Initially Constituted by HF, HNO<sub>3</sub>

• 作者: Brigitte Dustou Fabien Chauvet Jean-Michel Bergerat Laure Latapie Theodore Tzedakis
• 来源期刊: 分析科学方法和仪器期刊(英文)
• 学科: 化学
• 关键词: PICKLING Bath Monitoring Mix HF/HNO3 Titration Fluoride-Metallic Cations Complexation Titanium ALLOYS PICKLING Stainless Steel ALLOYS PICKLING
• 年，卷（期）: fxkxffhyqqkyw_2017,（4）
• 页码范围: 116-135
• 页数: 20页
• 分类号: O6

摘要

The present study couples the acid/basis titration and the ICP analysis in order to monitor the concentrations of nitric and hydrofluoric acids, and presents into baths used to pickle alloys of titanium or stainless steel, largely employed in the aeronautic industry. The pickling of the alloys releases various metallic cations able to react with HF in order to lead to metal-fluoride complexes and free H+, the last being able to react with the basis. In this study, it was determined: the most significant correlations providing the number of the protons released by the complexation of the metallic cation by the fluoride. The proposed method based on: 1) these correlations;2) the titration pH = f(VKOH) curves;and 3) the content of metallic cations determined by ICP, enables the monitoring of the content of HNO3 and HF into the pickling bath. Assuming that one bath was used for one type of alloy (alloys of Titanium for example, or alloys of stainless steel), then the proposed method appears providing reliable concentration values of both acids as well as metallic cations.