Ammonium Molybdate: Roasted Molybdenite Dissolved in Strong Ammonia (Gin 1907)

Roast molybdenite in air and its sulfur burns off, leaving a dirty yellow molybdic oxide. Strong ammonia dissolves that as ammonium molybdate; a little magnesium chloride throws out the phosphate and arsenate the ore brings with it. Gustave Gin gave this as his short route in 1907. Roast outdoors: the sulfur leaves as choking, poisonous sulfur dioxide. Source: G. Gin, Trans. Am. Electrochem. Soc. 12 (1907), pp. 421-422. The tools are ours. Picture drawn by Youblob.