If you mean grey cast iron and pH varies between 3 and 7 then no chance. Grey Cast Iron can do OK in concentrated sulphuric acid just like steel but its brittle so generally discouraged from use so ductile forms are used. If you are keen on using cast iron (otherwise some plastics or very expensive alloys may be your alternatives) then high silicon cast iron can handle a wide range of pH and even chlorides which grey cast iron has no chance in.
I agree with you regarding high silicon cast iron, it has very good resistance when introduced to acidic environment and it is not that expensive, I'll go for that one.
