Q: I’m using a pretty corrosive wet process to produce phosphoric acid. It involves taking phosphate rock and the addition of concentrated (93%) sulfuric acid in a series of well-stirred reactor. Any ideas on bolting that won’t corrode my bolts and fasteners?
A: Since your process is exposed to both sulfuric and phosphoric acid, I would suggest Hastelloy C276 bolts. C276 performs very well in phosphoric acid at all temperatures below boiling and concentrations to 65%. In addition, Hastelloy bolts also protect against sulfuric acid corrosion even in high temperatures and concentrations.