The invention provides a preparation method and a preparation device for a synthesis
ammonia prereduction catalyst. The preparation method comprises the following steps: feeding a synthesis
ammonia Fe catalyst into a reduction
tower, and introducing mixed
hydrogen and
nitrogen; then heating at a heating rate of 30-40 DEG C / h, and performing reduction reaction when the temperature raises to 365-380 DEG C; after the reduction reaction is over, discharging the mixed
hydrogen and
nitrogen out of the reduction
tower; when the temperature is reduced to be not higher than 50 DEG C and normal pressure is achieved, introducing
oxygen for passivating, wherein the pressure during the
passivation process is kept between 0.018MPa and 0.02MPa; and after the temperature is reduced to be not higher than 46 DEG C, finishing
passivation, thereby obtaining the synthesis
ammonia prereduction catalyst. In the preparation device, in-parallel double towers are adopted for the reduction
tower, a
passivation groove is omitted, heating reduction and passivation are performed in the reduction tower, and a method of negative pressure extraction by use of a circulating fan is adopted during the passivation process, so that the effective production time is obviously increased, the
reducing capacity is greatly improved, the operation difficulty is simplified,
power consumption is reduced, and the air inflow stability of a
system is ensured.