Ferrotungsten

a ferroalloy consisting of either 68–72 percent or 78–86 percent W and up to 7 percent Mo (Fe and impurities constituting the remainder). Ferrotungsten is produced in ore heat-treating furnaces by a combination of silicothermic and carbothermic-reduction processes from wolframite and scheelite concentrates. The ferrotungsten is scooped out of the furnace by the steel ladles of a special machine. High-grade ferrotungsten is smelted so as to form a block, which after cooling is broken down. Ferrotungsten is used mainly in the production of tool steels (high-speed steel) and heat-resistant alloys.