The production process of liquid fertilizers mainly includes the following steps:
Raw Material Preparation
Firstly, various raw materials are prepared according to the formula of liquid fertilizers. The raw materials generally include compounds of major elements (such as nitrogen, phosphorus, and potassium), such as urea, potassium dihydrogen phosphate, potassium nitrate, etc.; inorganic salts of trace elements (such as iron, manganese, zinc, copper, boron, molybdenum); and some additives, such as anti-caking agents, surfactants, etc. The purity and quality of these raw materials are crucial to the quality of liquid fertilizers.
Dissolution
The raw materials are added into the dissolution tank equipped with a stirring device in proportion according to the formula. First, add some water and turn on the stirrer to allow the raw materials to be fully mixed and dissolved in the water. During this process, it is necessary to pay attention to controlling the stirring speed and time to ensure that the raw materials are completely dissolved and form a uniform solution. For example, for some trace element salts with low solubility, it may be necessary to appropriately increase the temperature or extend the stirring time to promote dissolution.
Filtration
The dissolved solution is filtered through a filter to remove insoluble impurities in the solution, such as a small amount of solid particles in the raw materials. The precision of the filter is determined according to the product requirements. Generally, a filter screen or a filter cartridge type filter will be used to ensure the purity of the liquid fertilizer.
Mixing and Blending
The filtered solution enters the blending tank. Here, the content of various nutrients in the solution will be precisely adjusted to ensure that it complies with the nutritional ratio designed for the product. Moreover, the pH value and other indicators of the liquid fertilizer will also be adjusted, because an appropriate pH value helps to improve the stability of the fertilizer and the absorption efficiency of crops.
Testing
The blended liquid fertilizer needs to be tested for quality. The testing contents include the nutrient content (the content of nitrogen, phosphorus, potassium, and trace elements), pH value, density and other indicators. Professional testing equipment and methods are used to ensure that the various indicators of the liquid fertilizer meet the standard requirements.
Packaging
The liquid fertilizer that has passed the test is transferred to the packaging workshop. An automatic filling machine can be used to fill the liquid fertilizer into packaging containers such as plastic buckets, plastic bottles or flexible packaging bags. During the packaging process, attention should be paid to ensuring the tightness of the packaging to prevent the liquid fertilizer from leaking and deteriorating.