Process for preparing iron-based catalysts for the synthesis of ammonia and catalysts so obtained

摘要

A process for preparing iron-based catalysts for the synthesis of ammonia by melting magnetite or a mixture of iron oxides having the composition of magnetite, together with metal oxides as promotors, subsequent cooling of the molten mass and reduction thereof to the desired size, wherein the cooling occurs at a rate higher than 25'C min., preferably from 100°C_/min. to 1600°C min., at a temperature ranging from 1700°C to 700°C.;Such iron-based catalysts have a high activity in ammonia synthesis.;There are also disclosed catalysts having a reticular structure of the magnetite crystallites, surrounded by promotor metal oxides, the sizes which range from 10 to 100 µm.