Carbonylation process

A process for the production of nickel carbonyl wherein a mass comprising elemental nickel intimately mixed with at least one half mole per each 100 moles of nickel of at least one metal which forms sulfides more readily than nickel and is selected from the group of metallic iron, metallic copper and metallic cobalt in the temperature range of up to about 200.degree. C. is confined in a pressure retaining enclosure having walls chemically resistant to carbonylation and sulfidation and having a gas entry port and a gas exit port, mixing in said enclosure or in an extension thereof having walls chemically resistant to carbonylation and sulfidation a first gas stream containing carbon monoxide and devoid of hydrogen sulfide and a second gas stream containing hydrogen sulfide and devoid of carbon monoxide to provide a mixed gas stream containing about 0.01% to about 0.5% hydrogen sulfide based upon volume of carbon monoxide, reacting said mixed gas stream with said mass in said enclosure while maintaining the pressure in said enclosure at about 1 to 70 atmospheres absolute, while maintaining the temperatures in said enclosure at about 40.degree. C. to about 200.degree. C. and while maintaining an excess of metal which forms sulfides more readily than nickel to form nickel carbonyl and non-nickel sulfides and to remove hydrogen sulfide from said gas stream and withdrawing nickel carbonyl along with other volatile carbonyl from said enclosure through said gas exit port in a gas stream devoid of sulfur components.