摘要:
常用的尿素防结块剂按照作用部位可以分为粒内防结块和粒外防结块剂，粒内防结块剂以形成物理结构或者发生化学反应为途径，从尿素内部增强其颗粒强度，改善吸水性能，达到降低结块的效果；粒外防结块剂通常在尿素颗粒外部喷涂，形成一层包覆膜的形式隔绝尿素颗粒和空气中水分的接触，从而达到防结块的效果。典型的防结块剂甲醛有着组分单一且性能优异的优势，但是甲醛自身有毒性，在生产和使用的过程中会对人体和环境造成危害。因此,新型尿素防结块剂的发展趋势是开发绿色环保的复合型防结块剂:一方面,防结块剂原料配方中避免使用有毒有害物质；另一方面，防结块剂配方由多种原料共同组成，协同克服单一原料缺陷，达到更好的防结块性能。
关键词: 尿素；防结块剂；甲醛；复合防结块剂
Abstract: Commonly used urea anti-caking agents can be divided into intra-granular anti-caking agents and extra-granular anti-caking agents according to their functioning parts. Intra-granular anti-caking agents lower agglomeration by enhancing the strength of particles and improving their water-absorbing property from inside through forming special physical structures or chemical reaction. Extra-granular anti-caking agents are usually sprayed on the outside of the urea particles to form a layer of coated film to isolate the urea particles from the moisture in the air, so as to prevent agglomerates. The anti-caking agent is usually sprayed on the outside of urea granules to form a coating film to isolate the urea granules from moisture in the air, thus achieving the effect of anti-caking. Typical anti-caking agent formaldehyde, though with such advantages as single component and excellent performance, is toxic itself, which will cause harm to human body and the environment in the process of production and use. Therefore, new urea anti-caking agent trend is towards green composite anti-caking agents. On the one hand, toxic and hazardous substances can be avoided in the raw material of anti-caking agents. On the other hand, with a variety of raw materials to form anti-caking agents, shortcomings of a single raw material can be overcome to achieve a better anti-caking performance.
Keywords: urea; anti-caking agent; formaldehyde; composite anti-caking agent
关键词: 尿素；防结块剂；甲醛；复合防结块剂
Abstract: Commonly used urea anti-caking agents can be divided into intra-granular anti-caking agents and extra-granular anti-caking agents according to their functioning parts. Intra-granular anti-caking agents lower agglomeration by enhancing the strength of particles and improving their water-absorbing property from inside through forming special physical structures or chemical reaction. Extra-granular anti-caking agents are usually sprayed on the outside of the urea particles to form a layer of coated film to isolate the urea particles from the moisture in the air, so as to prevent agglomerates. The anti-caking agent is usually sprayed on the outside of urea granules to form a coating film to isolate the urea granules from moisture in the air, thus achieving the effect of anti-caking. Typical anti-caking agent formaldehyde, though with such advantages as single component and excellent performance, is toxic itself, which will cause harm to human body and the environment in the process of production and use. Therefore, new urea anti-caking agent trend is towards green composite anti-caking agents. On the one hand, toxic and hazardous substances can be avoided in the raw material of anti-caking agents. On the other hand, with a variety of raw materials to form anti-caking agents, shortcomings of a single raw material can be overcome to achieve a better anti-caking performance.
Keywords: urea; anti-caking agent; formaldehyde; composite anti-caking agent