酸性溶液中氟化物對鈦之腐蝕效應

The Effect of Fluoride on the Corrosion of Titanium in Acidic Solution

近年來台灣的火力電廠為減少硫氧化物的排放，開始在既有電廠加裝煙氣除硫（FGD）: Flue Gas Desulfurization裝置。但FGD設備成本昂貴，以興達電廠1、2號機為例，即高達40餘億元台幣。由於濕式吸收法的FGD裝置吸收效率較好，所以興達電廠參考各國經驗，也採用濕式FGD設備。

Due to the excellent corrosion resistance in high chloride environment, recently titanium was considered as a candidate material for flue gas desulfurization (FGD) system. Although titanium was highly chemically resistant, it was reported that titanium oxide was still attacked by concentrated sulfuric acid, notably by fluoric acid. Therefore this study was aimed to explore the effect of fluoride on the corrosion of titanium in simulated FGD acidic chloride solution. Corrosion tests employed the electrochemical methods including cyclic polarization and open circuit potential measurement. Electrochemical measurements were performed under controlling the solution temperature. The critical corrosion concentrations of fluoride at various temperatures were also determined. Using the X-ray Photoelectron Spectrum (XPS), the corrosion products were identified as TiO+2 • H2O, TiO2, and TiO • SO4 (or Ti(SO4)2). A corrosion mechanism was proposed according to this analysis.