In order to solve problems existing in the prior art, the utility model discloses a magnetic filter for liquid ammonia. The magnetic filter comprises a main body, an inlet, an outlet, a filter screen and a magnetic adsorbent, wherein the inlet and the outlet are respectively located at the left and right of the main body; the filter screen and the magnetic adsorbent are located between the inlet and the outlet; the filter screen and the magnetic adsorbent are fixed through fixing piles; and the magnetic adsorbent is zigzag, so that the adsorption area can be greatly increased, and the adsorption capability can be improved. The magnetic filter is a filter device which is simple in structure, lower in cost and capable of filtering out iron-contained impurities in liquid ammonia.

Liquefied ammonia is the primary raw material of producing nitric acid, the process of producing nitric acid is, liquefied ammonia generates gas ammonia through handling, be mixed into oxidation furnace with air in certain amount then and carry out oxidation, generate nitric acid through handling again, adopt platinum gauze as catalyst in the oxidizing process, owing to reasons such as production and pipeline conveyings, always have some ferrous contaminants to exist in the liquefied ammonia and since these ferrous contaminants with existing interception method can not filter to the greatest extent, so the ferrous contaminants in the liquefied ammonia always some is mixed in and enters oxidation furnace in the gas ammonia, these ferrous contaminants have entered oxidation furnace after stain platinum gauze, reduce
oxygenation efficiency, the platinum consumption is increased, improved cost.