Also known as liquid fertilizer, clear solution fertilizer, suspended fertilizer containing solid particles and anhydrous liquid ammonia general name. Fluid fertilizer does not require evaporation, drying and granulation in the production process, so it has low energy consumption, simple equipment, investment, no dust and smoke in the production and use process, and no moisture absorption and caking problems. Under the condition of special packaging and distribution system, transportation and loading and unloading are very convenient. The disadvantage is that the effective ingredient concentration is lower than the corresponding solid fertilizer, and the transportation cost is more expensive.
Liquid fertilizer is divided into liquid nitrogen fertilizer (including anhydrous liquid ammonia, ammonia water and nitrogen containing solution) and fluid compound fertilizer two categories: 1 Anhydrous liquid ammonia: N content is higher than 82.02%, containing H2O0.2% ~ 0.5%, oil content is less than 5ppm. In the United States, anhydrous liquid ammonia accounts for about 38% of the total nitrogen fertilizer application, and it is considered to be the cheapest nitrogen fertilizer. Nitrogen-containing solutions of various specifications are applied directly as nitrogen fertilizers, or as nitrogen sources for the production of complex fertilizers, and can be divided into atmospheric nitrogen-containing solutions and pressurized nitrogen-containing solutions, which are respectively ammonium nitrate or (and) urea aqueous solutions, ammonium nitrate and (or) urea and ammonia aqueous solutions. (2) Fluid compound fertilizer: nitrogen fertilizer, phosphate fertilizer and potassium fertilizer (salt) mixed aqueous solution or containing solid fertilizer (salt) suspension. One of the keys to its technological development is to find phosphate fertilizer raw materials with high solubility and no precipitation, and measures that can make solid particles more stable suspension in solution. The earliest source of phosphorus in fluid complex fertilizers was the purer crystalline diammonium phosphate, which was made by neutralizing thermal phosphoric acid or purified wet phosphoric acid with ammonia and was expensive. In recent years, ammonium polyphosphate solution is used, and its solubility is higher than diammonium phosphate. Polyphosphate ions have the function of chelating metal ions, which can keep metal ions and trace element ions brought into the raw material in the solution, preventing them from precipitating out as phosphate. Ammonium polyphosphate solution specifications (N-P2O5-K2O percentage) are 10-34-0, 11-37-0, etc., widely used in the preparation of fluid compound fertilizer, it with nitrogen solution and potassium chloride can be prepared into various specifications of products.