Method for producing composite fertilizer needed no drying

Abstract

The complex fertilizer producing process without need of drying step includes the following steps: pelletizing the solid material in a pelletizing machine, spraying 60-98 wt % concentration sulfuric acid solution into the pelletized material, adding liquid ammonia or gaseous ammonia for reaction to release heat for pelletizing, cooling and sieving to obtain pelletized complex fertilizer product. The process has the reaction heat well utilized, and has high pelletizing temperature, high balling degree, raised production capacity, lowered cost and saving in power.

Description

technical field

[0001] The invention relates to a production method of granular compound fertilizer, more precisely relates to a production method of compound fertilizer without drying. Background technique

[0002] Most of the existing compound fertilizers are produced with solid raw materials, that is, the basic raw materials containing nitrogen, phosphorus, and potassium are mixed and sent to the granulator. The materials are agglomerated into granules in the granulator, and the granulated materials are directly transported to Dried in a drying kiln, the dried material is cooled and screened to obtain qualified products. The production process of this technology is simple, and the operation is easy to master, but there are defects such as high moisture required when the material is granulated, large drying load, and low granule strength.

[0003] Chinese patent application CN1172095A discloses a method for granulating inorganic compound fertilizers. The method is to spra...