| Fertilizer is known as"food of food",with the increasing population,resource shortage,food security,environmental pollution and other problems,it is more and more urgent to innovate fertilizer in terms of improving fertilizer utilization,improving soil quality,reducing nutrient loss,reducing air and water pollution and so on.Among them,slow and controlled release fertilizers have been attracting much attention.Controlled slow-release fertilizer is the strategic requirement of China’s agricultural development.Its utilization rate is determined by the period of validity,release time and amount of fertilizer nutrients,which can greatly improve the utilization rate of nutrients,improve the quality and yield of crops,reduce resource waste and economic loss,and fundamentally reduce the pollution of soil,rivers and air.In this paper,based on the urine ammonium inclusion compound previously discovered by the research group,the application of this binary fertilizer inclusion compound and the preparation method of ammonium potassium sulfate binary fertilizer were studied.The main contents are as follows:1.The decomposition characteristics of urinary ammonium inclusion compound,urea and ammonium chloride in soil,and the inhibitory effect of urinary ammonium inclusion compound on soil urease were studied.The soil culture method and microbial culture method were used.The plate counting method was used to determine the results,and the results showed that the urea ammonium inclusion compound had a good inhibitory effect on urease,and the activity recovered on the fourteenth day of culture.The microbial culture method showed that the urea ammonium inclusion compound showed a good inhibitory effect on the microbial activity of decomposing urea in the soil.The mechanism has been discussed through infrared,solid ultraviolet,powder diffraction and so on.2.Based on the discussion in the above section,a high-tower granulation process was studied for the preparation of urine-rich ammonium inclusion compound from urea,ammonium chloride and calcium powder.The outer layer of the fertilizer was coated with heavy oil.The main contents included the raw material formulation,temperature,melting tank addition amount and other technological parameters,nutrient release rate of the fertilizer,and slow-release mechanism.The results showed that when the mass ratio of urea:ammonium chloride:calcium powder was40:40.5:19.5,more urine ammonium inclusion compounds could be formed,and the detection of soil culture method showed that it had a slow-release effect.The higher the temperature,the faster the release rate of nutrients,and the longer the effect of urea alone was about one week.The retention time of urea in soil is lengthened and the utilization rate is greatly improved.3.A new method for preparing ammonium potassium sulfate using molten urea as a medium and ammonium sulfate and potassium chloride as raw materials was studied and characterized.The study found that when the mass ratio of urea:ammonium sulfate:potassium chloride is 4:1:1,the melt has good fluidity,and the optimal temperature is 125°C-135°C,after thermal separation,it is washed and purified with 75%ethanol.There is no characteristic front of urea in the infrared spectrum,indicating that the product does not contain urea,the peak at 1418cm-1 has red shifted,and two new spikes appear at 2451cm-1 and 2419cm-1,indicating that new material is generated Scanning electron microscopy found that the sample showed smoothness and a small amount of impurities.The energy spectrum showed that the product contained K,O,and S elements,the impurities were unreacted urea,potassium chloride,and ammonium sulfate.This method can be used to produce ammonium potassium sulfate binary compound fertilizer,which has the advantages of neutralizing reaction conditions,low requirements on equipment,simple operation,and by-products can be used to prepare compound fertilizers. |
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