Question

Which of the following metal is suitable in handling high concentrations (>60%) of hydrofluoric acid?

(a) Stainless steel

(b) Brass

(c) Steel

(d) Titanium

I have been asked this question in examination.

My question is from Mineral Acids in section Mineral Acids of Corrosion Engineering

Answer 1

The correct answer is:

(d) Titanium

Explanation:

Titanium is highly resistant to hydrofluoric acid (HF), even at high concentrations (>60%). Unlike many other metals, titanium forms a passive oxide layer on its surface that protects it from corrosion by hydrofluoric acid. This makes it an ideal choice for handling HF in industrial settings, particularly when the acid concentration is high.

• Stainless steel, brass, and steel are generally susceptible to corrosion when exposed to hydrofluoric acid, particularly at higher concentrations. These materials can break down due to the aggressive nature of HF, leading to metal dissolution and damage. Therefore, titanium is the most suitable choice for handling concentrated hydrofluoric acid.