Method for producing nitrogen-fixing potassium slow-release compound fertilizer with mesh inner membrane by using ammonia-acid method

Abstract

The invention discloses a method for producing nitrogen-fixing potassium slow-release compound fertilizer with mesh inner membranes by using an ammonia-acid method. The compound fertilizer comprises the following added raw materials: natural minerals capable of fixing and absorbing nutrients, and raw materials capable of forming shells with porous multiple layers of mesh inner membranes; and calcium salt is used to form a packaging skeleton and fix nutrients. The added concentrated sulfuric acid is divided into two parts, wherein one part is prepared into an ammonium sulfate solution of 180-220 DEG C with ammonia and water, amino acid reaction heat is controlled through controlling the added amount of water, and then the ammonium sulfate solution is sprayed into a granulator to granulate with powdery basic materials which contain nitrogen, phosphorus, potassium and natural minerals and are capable of forming shells with mesh inner membranes; and the other part is diluted and then directly added into the granulator to react with urea to generate thiocarbamide, and then drying, cooling, screening and enveloping are carried out on thiocarbamide after granulating to obtain the slow-release compound fertilizer containing nitrogen, phosphorus and potassium. In addition, two-section drying is changed to one-section drying, which can meet the requirements of production.

Description

technical field [0001] The invention relates to a production method of a slow-release compound fertilizer, in particular to a production method of a slow-release compound fertilizer for nitrogen-fixing potassium in the reticular inner membrane of an acid method. Background technique [0002] At present, with the development of modern agriculture, the development of compound fertilizers at home and abroad has taken a leading role in the chemical fertilizer industry. In developed countries of the chemical fertilizer industry, the amount of compound fertilizers has accounted for 70% to 80% of the amount of chemical fertilizers. However, long-term large-scale application of chemical fertilizers not only increases crop production, but also has a great negative impact on soil, crops and the environment. Studies have shown that conventional chemical fertilizers have a large amount of nutrients, concentrate and release quickly in the early stage of application, which will cause leach...

AI Technical Summary

Problems solved by technology

At present, the domestic production of slow-release fertilizers is more common to coat the surface of fertilizer particles with a layer of insoluble inert film to delay the dissolution and diffusion of fertilizers and achieve the purpose of slow release. However, the thickness of the film cannot be controlled, which leads to the rapid release of some nutrients. , some nutrients cannot be released

The chemical coating agent used in slow-release fertilizers using chemical coating agents is generally an inert polymer compound. After the nutrients are released, the coating agent remains in the soil and is difficult to degrade, which will cause secondary pollution to the soil environment.

Moreover, the cost of using high-grade inert film is high, and the price of the slow-release fertilizer produced by it is as high as 6,000-8,000 yuan / ton. Therefore, it can only be used for economic crops, and field crops are not acceptable at all.

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