Nickel in one form or another has literally hundreds of thousands of individual applications. Annual world production of nickel products in recent years has averaged in excess of 1,100 kilotonnes. Primary nickel products are classified by the amount of nickel they contain. Class I products contain almost 100 percent nickel, whereas Class II products vary widely in their nickel content.
Most primary nickel is used in alloys, the most important of which is stainless steel. Other uses include electroplating, foundries, catalysts, batteries, welding rods, coinage, and other miscellaneous applications. The list of end-use applications for nickel is, for all practical purposes, limitless. Nickel is found in transportation products, electronic equipment, chemicals, construction materials, petroleum products, aerospace equipment, durable consumer goods, paints, and ceramics. From this list, it is evident that nickel is a critical metal to industrialized societies.