The Technology On Potassium Sulfate Granulation In Lop Nor

Agriculture is the foundation of national and economic development.Chinese has always believed that agriculture is a strategic industry that is safe and stable.China is a country with serious potassium deficiency,but potash fertilizer is indispensable to agricultural production.In particular,granular potash fertilizer is the trend of agricultural development in the future.It is characterized by slow application,easy storage and high utilization ratio.Lop Nor Salt Lake is rich in potash resources.But because of the special physic and chemical properties of potassium sulfate,the products are basically exported in powder,so potassium sulfate granulation is difficult to realize industrialization.Potassium sulfate granulation technology is an effective means to improve the utilization rate of potassium fertilizer and alleviate the shortage of domestic potash fertilizer resources.In this paper,the effects of material moisture,material temperature and material ratio on the granulation effect of potassium sulfate are investigated.The results show that the suitable granulation technical parameters are dry extrusion at room temperature and no binder.The grain strength of potassium sulfate pelletizing product is about 30 N,and it is found that the addition of super fine material will reduce the strength of potassium sulfate particle,and the binder has little effect on potassium sulfate granulation,and raising the material temperature will not improve the granulation result.The aim of this paper is to improve the strength of extruded particles in potassium sulphate mill.The results show that the strength of particles can be improved by mixing,grinding for 4 minutes before granulating and spraying water before drying.The industrial test results show that the technological process of controlling the product granularity to return to the raw material by twice sieving,the final particle size is 2.5 ~ 5.0mm and the strength is about 40 N after repeated industrialization debugging.In order to ensure the product quality,the drying section should be added in the later process design by increasing the strength of potassium sulfate granules.The experiment of potassium sulfate granulation in roller extruder by MP280 and DH850,and the stability test of extrusion granulation system,fully prove the feasibility of robub potassium sulfate granulation technology.As well as investment and operation cost,domestic DH850 extrusion equipment is recommended to carry out project design and construction work.In this paper,the suitable process parameters for Lop Nor potassium sulfate powder granulation were studied,and the suitable granulation technology was successfully developed,and the product quality,particle strength and molding rate were all satisfied.The company plans to build a 300,000 t /a production line suitable for Lop Nor potassium sulfate powder granulation,which can create its own granulated brand products and further develop the company's granular potassium sulfate product market.It lays a theoretical foundation for the granulation industrialization of potassium sulfate powder.In addition,it can be extended to the development of large-scale equipment and continuous production system in industrial production.This also provides a good reference for large-scale industrial production of granular potassium sulfate fertilizer in China.