Synergistic calcium superphosphate and preparation method and application thereof

Abstract

The invention belongs to the field of fertilizer industry and discloses synergistic calcium superphosphate and a preparation method and application thereof. The preparation method comprises the steps of preparing organic acid, amino acid or other small-molecular organic matters containing a large number of low molecular weights by utilizing acid hydrolysis of agricultural wastes and secondary hydrolysis of wastes from a food processing plant, then taking the substance as a synergist I, then adding calcium superphosphate into the synergist I, and uniformly drying and crushing to obtain powdery sustained-release synergistic calcium superphosphate; or uniformly mixing the synergist I, a suspending agent and an emulsification coating agent to prepare a synergist II, then adding calcium superphosphate into the synergist II, and performing high-speed shearing and uniform mixing by a colloid mill to obtain liquid sustained-release synergistic calcium superphosphate. The synergistic calcium superphosphate obviously reduces the opportunity of adsorbing phosphorus by soil colloid or fixing phosphorus by iron ions and the like, increases the effectiveness of phosphorus and improves the utilization rate of fertilizer. The method has the advantages of simplicity, convenience, easiness in operation, capability of saving energy and raw materials and effect of reducing production cost. The synergistic calcium superphosphate disclosed by the invention can be applied to the field of agricultural production of vegetables, fruit trees and the like.

Description

technical field [0001] The invention belongs to the field of fertilizer industry, and in particular relates to a synergistic calcium superphosphate and its preparation method and application. Background technique [0002] Phosphorus is one of the essential nutrients for crop growth. At the same time, the critical period of phosphorus nutrition for most crops is in the early growth stage. If the soil phosphorus deficiency is serious, it will have an irreversible impact on the yield and quality of crops. According to statistics, 43% of the world's agricultural soil is deficient in phosphorus, and the area of ​​phosphorus deficiency in my country's farmland is as high as 67%. Depending on the nature and composition of the soil, the reaction occurs quickly to form adsorbed or slightly soluble phosphate compounds such as Ca 2 -P, Ca 8 -P, Al-P, Fe-P and other forms (Ma Yibing et al., 1993; Liu Jianling et al., 1996; Lu Wenlong and Zhang Fusuo, 1998; Akhtar, 2003; Xia Wenjian et ...

AI Technical Summary

Problems solved by technology

Commercial superphosphate is off-white powder or granules, containing 14%-20% of available phosphorus, and 3.5%-5% of free sulfuric acid and phosphoric acid. Because it contains free acid, the fertilizer becomes acidic, corrosive, and easy to absorb moisture. block, poor scatter

After moisture absorption, the monocalcium phosphate in it is easily converted into insoluble iron phosphate and aluminum phosphate, resulting in a decrease in the effectiveness of phosphorus; Phosphorus fixation

At the same time, the pH value of superphosphate is low, generally lower than the soil pH, and is easily affected by the acid-base ions of the soil solution, which leads to a rapid increase in the pH value of the fertilizer solution, and the increase in pH will reduce the level of available phosphorus, and at the same time the pH Rapid changes in values ​​also increase the chances of metal ions fixing phosphorus

[0004] Chinese patent (publication number: CN101033155A) has reported a kind of rare earth additive and the rare earth superphosphate containing this additive and preparation method thereof, but this invention just adds rare earth element, does not consider the existence form of superphosphate, also Problems such as phosphoric acid degradation are not considered; Chinese patent application (publication number: CN101481273A) reports a method for preparing polypeptide superphosphate and its application in agriculture. This invention is a physical mixture of superphosphate and polypeptide without chemical reaction. And also do not explore the impact of polypeptide on the effectiveness of superphosphate applied to the soil, and the price of polypeptide added is more expensive, which increases the cost; Mixed fertilizer and its application, this invention uses the method of leaching to dissolve the water-soluble substances in superphosphate. On the one hand, the solubility of calcium dihydrogen phosphate is low, and a large amount of water is needed to dissolve it. Phosphorus cannot be used

However, there are few patent reports on enhancing the effectiveness of phosphate fertilizer by changing the form of superphosphate, and discussing the changes in physical and chemical properties (slow release, buffering) of the fertilizer after it is applied to the soil.

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