3862.  WALLIS, A.E., AND TOWNSHEND, S.C. (International Nickel Co. of Canada, Ltd.). Iron Carbonyl. Canadian Patent 453,853, Jan. 4, 1949. Chem. Abs., vol. 44, 1950, p. 1659.

Iron ore (I) is immersed in Ni_SO₄ until the (I) absorbs an amount of Ni_SO₄ equal to not above 2% by weight (I). (I) is reduced by H₂ at about 500° , and the mixture is caused to react with CO at about 200 atm. pressure at about 140° to effect 100% conversion to Fe carbonyl in 4 hr.