| 摘要 |
In the synthesis of ammonia under pressure an iron catalyst is used containing in addition to one or more of the usual activators a small proportion of arsenic, boron, or phosphorus or a compound thereof. The catalyst is obtained by fusing an oxide of iron or by subjecting reduced iron to an oxidizing fusion in the presence of the other ingredients and subsequently reducing the product in the contact furnace at 450-500 DEG C. Specific examples of catalysts are (1) iron containing 10 per cent of calcium oxide and 3,3 per cent of calcium arsenate; (2) iron with 25 per cent of potassium nitrate and 6,25 per cent of boric acid; (3) iron with 25 per cent of potassium nitrate and 12,5 per cent of ammonium phosphate. Equivalent amounts of elementary boron and phosphorus may be substituted in the two last examples. |
