Caking cause and preventive measures of urea-based compound (mixed) fertilizer

Reasons for compound (mixed) fertilizer agglomeration

The main raw materials for the production of composite (mixed) fertilizers in China are: urea, ammonium chloride, ammonium nitrate, ammonium sulfate, diammonium phosphate, monoammonium phosphate, superphosphate, heavy calcium, potassium chloride, potassium sulfate, etc. Larger solubility, so composite (mixed) fertilizers made from them tend to agglomerate during storage and transportation. The factors affecting the agglomeration of composite (mixed) fertilizers are mainly reflected in the following aspects:

(1) The water content of the product is higher, the salt between the particles is dissolved - the crystallization process is easier to carry out, and the easier it is to agglomerate.

(2) Packing temperature The packaging temperature is high, the moisture inside the product is not fully released, and it is easy to agglomerate; the product temperature is low, it is easy to absorb moisture from the air, and it is easy to agglomerate.

(3) Storage pressure The fertilizer particles are under heavy pressure, the particles are in closer contact, the particles are deformed, and the contact surface is increased, thereby causing agglomeration.

(4) Storage time Fertilizer products will continue to react for a certain period of time after packaging, such as moisture absorption, dissolution, recrystallization, metathesis between salts, etc. This process lasts for a long time, so the longer the storage time The more serious the agglomeration.

(5) The shape of the particles is small and irregular in shape, multi-angular, and the specific surface area is larger and it is easier to agglomerate.

(6) Uniformity and hardness of the particles The particles are not uniform, and the contact area is increased; when the hardness is low, the crushing is easy, resulting in an increase in contact area and easy agglomeration.

(7) The composition of the impurities in the particles and the composition of the impurities with different contents may affect the degree of crystal crystallization and the size of the crystal particles, thereby affecting the degree of agglomeration.

Urea-monoammonium phosphate--potassium chloride-based composite (mixed) fertilizer anti-caking method

(1) Adding an appropriate amount of formaldehyde formaldehyde and urea to form dimethyl diurea, which not only slows the agglomeration, but also slows the urea, thereby improving the fertilizer utilization rate.

(2) In the urea (or in the urine), gypsum powder gypsum (CaSO4·2H2O) is added to react with urea to form a stable double salt CaSO4·4CO(NH2), thereby slowing down the formation of double salts between urea and other substances.

(3) Prolonged cooling time The cooling is not complete, which will cause the internal moisture of the particles to transfer to the surface, resulting in the dissolution and crystallization of surface salts. It is expressed in the urea-based compound (mixed) fertilizer. As the temperature decreases, the double salinization rate increases, leading to agglomeration.

(4) Increasing the number of overturning or building a bulk warehouse In view of the slow reaction process of the composite (mixed) fertilizer, it is appropriately turned over during storage (similar to the principle of building a bulk storage warehouse). At the beginning of storage, the degree of agglomeration is not very serious. Once the package is turned over, the agglomeration will be loose, thus prolonging the storage period.
【Comment】 【Print this article】 【Close this page】 【Large, medium and small】

PVC Water Stop

Rubber Seal Strip Co., Ltd. , http://www.nsrubberseal.com