A coated double slow release fertilizer and a preparing method thereof

Abstract

A coated double slow release fertilizer and a preparing method thereof are disclosed. The fertilizer is prepared from papermaking black liquid, a sulfuric solution having a concentration of 10 wt%, a formaldehyde solution having a concentration of 5%, sodium sulfite, montmorillonite powder, cyclodextrin, agar powder, aldol resin, citric acid, magnesium sulfate, farm-oriented rare earth, potassium chloride, ammonium humate, oxalic acid, manganese sulfate, potassium permanganate and a proper amount of water by weight parts. Coating is adopted, the water content of particles of the fertilizer is controlled firstly, and the particles are sprayed with a coating material adopting stone powder as a main material, thus effectively preventing adhesion among the fertilizer particles, preventing rapid splitting of the fertilizer particles, and largely prolonging the fertilizer using time. Surfaces of modified lignin particles are provided with certain sodium lignosulphonate components capable of adsorbing cations, thus promoting fertilizer absorption and preventing water and soil loss.

Description

technical field [0001] The invention belongs to the technical field of fertilizers, and in particular relates to a coated double slow-release fertilizer and a preparation method thereof. Background technique [0002] The alkaline pulping process widely used in the paper industry, whether woody or non-woody plants are used as raw materials, produces a large amount of black liquor by-products. According to statistics, the global annual output of black liquor is about 500 million tons, and about 70% of the black liquor is The solids are organic matter, including lignin, hemicellulose, and cellulose degradation products. Lignin is a complex polymer compound that exists in the xylem of most land plants. There are about 10 million tons of lignin. At present, most of the black liquor is concentrated to 45-60%, then burned and recovered by alkali, resulting in a huge waste of lignin, a renewable resource contained in it, and papermaking black liquor flows into the environment, caus...

AI Technical Summary

Problems solved by technology

At present, most of the black liquor is concentrated to 45-60%, then burned and recovered by alkali, resulting in a huge waste of lignin, a renewable resource contained in it, and papermaking black liquor flows into the environment, causing high pollution and containing a large amount of The pollutants contained in organic fibers, inorganic salts and pigments account for more than 90% of the pollutants in the papermaking industry, and they are highly alkaline, dark in color, heavy in odor and rich in foam, and consume a large amount of dissolved oxygen in water, causing serious damage to the environment. the destruction of