From a technical point of view, the important factor in the formulation design of extrusion granulation products in NPK fertilizer production line is the characteristics of materials. Next, we discuss another aspect of the influencing factors, that is, the influence of the type of raw materials on the formula.
1. Material compatibility
Theoretically, any proportion of NP or K base fertilizer can be prepared, and trace elements and even pesticides should be added if necessary. However, materials must be limited by compatibility. The substances in the formula shall not have chemical reaction in the process of fertilizer manufacturing, and occasional reaction shall not be allowed.
2. Effect of urea on formula
The international fertilizer center has done a lot of experiments on the effect of urea on the performance of compound fertilizer, although the report does not mention the same example as the product formula we are studying, and most experiments do not carry out granulation on extrusion. Yes, but its conclusion is still useful to us.
Because urea absorbs moisture easily, the critical relative humidity of NPK compound fertilizer decreases significantly. At the same time, the international fertilizer center also found that this effect is more serious when potassium chloride is used as the potassium source of compound fertilizer.
Due to the low critical relative humidity, urea based compound fertilizer is easy to absorb water, which blocks the screen, pipeline, chute, etc.
When the temperature increases, the critical relative humidity of urea based compound decreases rapidly.
The production capacity of the dryer must be determined by many factors. Some urea based NPK fertilizers begin to soften at 70 ℃. If the outlet temperature of the dryer is higher than this temperature, the fertilizer particles will be too soft, the granulation process will be out of control (the particles are too large), and the internal scabs will form. Drying causes difficulties in screening and transportation.
In the same report, the international fertilizer center also tested other aspects of urea, such as water absorption, moisture permeability, water holding capacity, particle integrity, fluidity and agglomeration. The result is negative, which will have an adverse effect.
In short, the formula design test and production of extrusion granulation products in compound fertilizer production line show that the use of urea in compound fertilizer will encounter great trouble, not only because it affects the storage and transportation performance of products, but also because it also has a certain impact on the production process.
More info on npk fertilizer production, welcome go to https://www.fertilizer-plants.com/compound-fertilizer-production-line/