Refractory metals are a class of metals that are extraordinarily resistant to heat and wear making them more expensive to be obtained.
Refractory metals are somehow rare compared to base metals.
Refractory metals are particular as they can withstand very tough operating conditions. These qualities come from their particular properties rendering difficult their processing that we will describe in this book from heavy sands processing, especially for titanium, zirconium, tungsten, molybdenum, vanadium, and rhenium.
Roger Rumbu, Met. Eng., PPM, TBOM.