METAL PASSIVATION Russian patent published in 2011 - IPC C01B3/38 C23F11/02 

FIELD: process engineering.

SUBSTANCE: invention relates to chemistry. For passivation of low-alloy steels at plants operated at 350 to 580°C and subjected to gas mix containing carbon monoxide, passivating compound containing, at least, one phosphorus atom is added to said gas mix. Low-alloy steel comprises iron and one or more alloying elements selected from the group containing chromium, molybdenum, vanadium, nickel, niobium and carbon with total amount of components, other than iron, making, at least, 12 % by wt. To produce dehydrated synthesis gas, one or more stages of catalytic steam reforming and/or partial oxidation of gaseous mix are carried out at temperature above 580°C. Produced mix of gases is cooled and condensed water is separated. Prior to cooling said gas mix to 580 to 350°C in the plant with low-alloy steel surface, passivating compound containing, at least, one phosphorus atom is added to said gas mix.

EFFECT: higher efficiency of metal surface passivation.

13 cl, 3 ex