The compound NPK and NPK blends are multi-nutrient fertilizers containing a certain proportion of all three major nutrients: nitrogen (N), phosphorus (P) and potassium (K). These products allow the crop to be fully applied once in one application. The raw materials for each nutrient will vary depending on the NPK fertilizer production process.
In the production of NPK compound fertilizer, some of the processes used are accumulation, in which the fertilizer slurry is repeatedly applied to the solid "seed" particles and dried to form an "onion skin" structure similar to diammonium phosphate (DAP) or phosphoric acid. Ammonium hydrogen (MAP) production. Other NPK compound fertilizers are produced by agglomeration processes in which the main raw materials are supplied as dry solids and then interconnected and bonded by steam, liquid salt solution, ammonium phosphate slurry and/or ammonium nitrate solution. However, in addition to the aggregation process based largely on physical extrusion granulation, there are also processes for obtaining a liquid phase by chemical reaction of ammonia with sulfuric acid, nitric acid or phosphoric acid, wherein the granulation is carried out in a drum granulator or a prilling tower. get on. Both compound fertilizer NPK processes form a homogeneous fertilizer because the same NPK analysis is performed for each particle.
In NPK mixed fertilizer, there is a very simple mixture of various types of dry fertilizers, such as urea, ammonium sulfate, ammonium nitrate, diammonium phosphate, ammonium dihydrogen phosphate and some forms of potassium salt, in order to achieve The average value of NPK in the total blended fertilizer in the input and ratio analysis. In theory, in bulk compound fertilizers, there will be particle inputs of similar specifications and structures, so the nutrient distribution is relatively consistent. If not consistent, the established input in the compound fertilizer can be separated, which will result in an unexpected change in the NPK assigned to the field at the time of final application.
Compound Fertilizers NPK manufacturers typically perform some sort of analysis of NPK production processes and are somewhat limited by the number of different analyses of NPK SKUs they can actually produce and store. However, bulk compound fertilizers are usually produced downstream of the supply chain, closer to the end-use points, and can be quickly customized to be converted into almost unlimited quantities of NPK products with temporary notice.
One of the most economical and most commonly used nitrogen inputs for NPK fertilizers is urea, but its hygroscopicity and plasticity greatly increase the tendency of urea-based NPK fertilizers to agglomerate during storage. This tendency is exacerbated when NPK also contains the most commonly used potassium, potassium chloride (MOP). Such products also undergo significant degradation and dust generation during storage and handling.