The rubber-versus-metal question comes up in almost every application review, and the honest answer is rarely "metal is better" or "rubber is better." It is "which matches this specific slurry."
In our workshop the quick test is particle size and impact. Fine, low-impact slurries — many tailings and flotation duties — usually favor rubber, which can outlast metal there. Coarse, sharp, high-head slurries favor high-chrome metal, because rubber tends to tear rather than wear gradually. pH and temperature then narrow the choice further.
The mistakes we see are usually about ignoring one variable. A plant picks rubber for cost, then feeds it coarse concentrate and wonders why it cuts. Or it runs metal everywhere, including fine duties where rubber would have lasted longer and run quieter.
Our rule of thumb: decide by the full duty — particle size, concentration, pH, head — not by habit. When we are unsure, we would rather run a trial on the actual slurry than guess from a nameplate.
