Research And Preparation On Urea Anti-caking Agents

Urea is in dominating status in all kinds of chemical fertilizers for its high nutrition nitrogen element, but urea is easy to agglomerate and lead to the gradual disappearance of free mobility and make its quality become coarseness in process of transportation and storage. Consumers have been influenced seriously for a period of long time. Therefore, the research on agglomeration reason and anti-caking technology of urea is very important.In this dissertation, a fast evaluation method of urea anti-caking agents'performance was designed and the factors on the agglomeration of urea were discussed. Meanwhile we make use of the waste of octadecylamine and hydrogenated tallow amine produced by Jiangsu Fly Chemical Co., Ltd. and prepare urea anti-caking agents. The main contents are as follows:(1) A fast evaluation method of urea anti-caking agents'performance was designed: Firstly, urea was filtered and dry by 6 and 16 mesh sieves. Then about 15g filtered urea was added to a Petri dish of 6 cm diameter and put a weight of 100 g above the top of urea. Take the Petri dish out of the incubator for minutes then remove the weight. The Petri dish was reversed to 5cm high above the desktop and fell vertically. Finally, the urea was poured into Petri dish which was filtered by the 6 mesh. The moisture absorption rate and agglomeration rate were weighted and calculated.(2) The moisture absorption rate and agglomeration performance of the urea were investigated by different temperature, humidity and storage time. By comparison, we arrive at the result that the urea's hydroscopicity and agglomeration rate were 2.41% and 39.77% under the temperature of 35℃,the relative humidity of 80% and the storage time of 4.5h, and we also have acted a standard for the following experiments as a reference.(3) The anti-caking agents were made by octadecylamine and hydrogenated tallow amine waste solid.0.09 g octadecylamine was added into 50 mL paraffin and sprayed uniformly to the surface of 500 g urea under the conditions of 40 r/min and 45℃in lmin, the moisture absorption rate and agglomeration rate was determined 1.51% and 24.15% by the fast evaluation of urea anti-caking agents'performance. While 0.18 g hydrogenated tallow amine was added into 50 mL paraffin and sprayed uniformly to the surface of 500 g urea under the conditions of 40 r/min and 45℃in 1min, the moisture absorption rate and agglomeration rate was determined 1.13% and 27.09% by the fast evaluation of urea anti-caking agents' performance. It was found that the performance of these anti-caking agents is distinct.