Method for preparing large-granulated fertilizer

Abstract

The invention discloses a method for preparing a large-granulated fertilizer. The method comprises the following steps: (A) mixing materials: uniformly stirring ammonium phosphate, potassium chloride, phosphate rock powder, bone meal, sustained-release resin, heavy calcium carbonate and a mixture, which is prepared from calamine powder and oil residue according to the mass ratio of 2: 7, and then, adding into a heated reactor; (B) heating and pressurizing: controlling the heated temperature of the reactor to 200-300 DEG C while pressurizing to 1.6 times of the original pressure, and then, carrying out heat preservation and pressure maintaining for 15-20 minutes, so as to obtain molten slurry for later use; (C) preparing the large-granulated fertilizer: pouring the molten slurry into a mold, and carrying out water-cooling and demolding, so as to form the large-granulated fertilizer, wherein the diameter of the large-granulated fertilizer is 5-8cm, the mold is formed through integrally connecting a plurality of spheroidal structures, and a cooling water curtain flows through the external surface of the mold; (D) preparing coatings: coating the external surfaces of spheroidal granules, obtained in the step (C), with molten sulfur, so as to form sulfur coatings, of which each has the thickness of 2-3mm. The method disclosed by the invention is simple, and the prepared product is simple in proportioning, long in fertilizer effect and convenient and rapid in fertilization.

Description

[0001] Technical field: [0002] The invention relates to the technical field of fertilizers, in particular to a method for manufacturing large-grain fertilizers. [0003] Background technique: [0004] In today's agricultural production, it is usually necessary to use fertilizers to increase agricultural production. During the fertilization process, it is necessary to use a spreader or fertilization equipment to spread the fertilizer after furrowing. Traditional fertilizers are all in the shape of fine particles, usually spherical particles with a size of 3-5mm. However, the traditional fertilizer particles are too small, especially when fertilizing by hand, it is difficult to control the amount, so fertilization is time-consuming and laborious. The fertilizer with too small particles has a small slow release degree and short fertilizer effect time. For this reason, need to occur a kind of manufacturing method simple, the product proportioning of making is simple, and fer...

AI Technical Summary

Problems solved by technology

Traditional fertilizers are all in the form of fine particles, usually spherical particles with a size of 3-5mm. However, traditional fertilizer particles are too small, especially when fertilizing by hand, it is difficult to control the amount, so fertilization is time-consuming and laborious.

The fertilizer with too small particles has a small degree of slow release and short fertilizer effect time.