Tungsten Powder: Wolfram Fused with Soda, Tungstic Acid Reduced with Carbon in Crucibles (Oxland Process, Thorpe 1913)

How tungsten powder for steelmakers was made: wolfram is roasted with soda to sodium tungstate (Oxland's process of 1847), the tungstate is poured into boiling hydrochloric acid to throw down tungstic acid, and that is reduced with a little less than its carbon in crucibles. Washing takes off the free carbon and the finest dust. Result: fine-grained, granular tungsten powder, usually over 98 % tungsten with about 0.5 % each of iron and silicon and under 0.5 % carbon. Source: Thorpe, A Dictionary of Applied Chemistry vol. 5 (1913), pp. 564-565. Not given: crucible, reduction temperature and time, the vessels for the acid. Boiling hydrochloric acid is a strong acid. Picture drawn by Youblob.