Abstract A catalyst for ammonia synthesis having a high catalytic activity and good physical-chemical characteristics is prepared by gradually melting an iron bar above a steel crucible cooled on the outside with water. The melting is carried out uninterruptedly over a period of 16 minutes by directing onto the melting end of the bar an oxygen stream, e.g. at a pressure of 0.15 atm. An oxidizing melting reaction of the iron occurs which being exothermal has the effect of raising the temperature. The ferrous oxide flows into the crucible and concomitantly are added the promoters, i.e. Al2O3, K2CO3, SiO2, CaO. An inhomogeneous fluid mass results. The crucible is then closed and oxygen is fed in, producing inside the crucible (over a period of 3 minutes) a pressure of 2 kg/sq cm. Feeding of oxygen is then stopped and the crucible is immediately discharged. The molten mass is cooled, crushed, sized and packed.
The method defined in claim 1 wherein said stream of oxygen has a pressure of about 0.15 kgf/cm2.
Claim 2
Dependent Claim
24 words
The method defined in claim 2 wherein the molten ferrous oxide is oxidized in a crucible under an oxygen pressure of substantially 2 kg/cm2.
Claim 3
Dependent Claim
31 words
The method defined in claim 3 wherein said body is melted at a temperature of substantially 1,727* Centigrade and said mixture is oxidized at a temperature of at least 1,369* Centigrade.
Claim 4
Independent Claim
159 words
A method of making an unreduced catalyst for the synthesis of ammonia in a reduced state, comprising the steps of: continuously melting at a temperature up to about 1,727*C an iron body in the presence of only sufficient oxygen at a pressure of about 0.15 kg/cm2 to form ferrous oxide from the melt and concomitantly mixing the ferrous-oxide melt with at least two ammonia-synthesis-catalyst promoters selected from the group consisting of Al2O3, K2CO3, SiO2 and CaO; and thereafter rapidly oxidizing the mixture under an oxygen pressure of substantially 2 kg/cm2 and at a temperature of at least about 1,369*C to convert the ferrous oxide at least in part to ferric oxide while inducing ebullition of the mixture, all four of the members of said group being added during the oxidizing melting of said iron bar in the proportion of 1.5 kg Al2O3, 0.8 kg K2CO3, 0.5 kg SiO2 and 2.4 kg CaO per 36 kg of the iron bar.