Ammonium phosphate slow-release fertilizer with high sulfur content and preparation method of ammonium phosphate slow-release fertilizer

Abstract

The invention relates to the technical field of sulfur containing slow-release fertilizers, in particular to an ammonium phosphate slow-release fertilizer with high sulfur content and a preparation method of the ammonium phosphate slow-release fertilizer. Water, a dispersing agent, a humidizer and a thickener are uniformly mixed, a mixed solution is obtained, the mixed solution and sulfur granules are mixed and ground in a wet type grinding machine, sulfur coating slurry is prepared, the adding quantity of the sulfur granules is limited to be 30%-70% of the quantity of the sulfur coating slurry, and accordingly, dust is not formed in the grinding process; the dispersing agent, the thickener and the humidizer are added for grinding, so that hydrophilization of the surfaces of the sulfur granules is realized, the prepared sulfur coating slurry becomes hydrophilic groups and sprayed in a coating machine to coat surfaces of ammonium phosphate granules, further, a finished product is prepared, the content of sulfur in the prepared finished product is 5%-20%, the content of nitrogen is 15%-16%, and the content of phosphorus is 41%-43%. The quality of the sulfur containing ammonium phosphate slow-release fertilizer is improved, the potential safety hazard of sulfur dust to the production environment is reduced, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of sulfur-containing slow-release fertilizers, in particular to a high-sulfur-content ammonium phosphate slow-release fertilizer and a preparation method thereof. Background technique [0002] The sulfur source of sulfur-containing ammonium phosphate slow-release fertilizer is mainly divided into two types, one is sulfur trioxide and the other is elemental sulfur; the method of using sulfur trioxide as a sulfur source is to react sulfuric acid or sulfate with ammonium phosphate , to obtain ammonium phosphate ammonium fertilizer. During the preparation process, due to the addition of sulfuric acid, the preparation cost is relatively high, and sulfur trioxide is easily formed after the prepared sulfur-containing ammonium phosphate compound fertilizer is fertilized into the soil. The gas is emitted in the air, which not only causes the nutrient loss of the slow-release fertilizer to be lost quickly, but also ca...

AI Technical Summary

Problems solved by technology

[0002] The sulfur source of sulfur-containing ammonium phosphate slow-release fertilizer is mainly divided into two types, one is sulfur trioxide and the other is elemental sulfur; the method of using sulfur trioxide as a sulfur source is to react sulfuric acid or sulfate with ammonium phosphate , to obtain ammonium phosphate ammonium fertilizer. During the preparation process, due to the addition of sulfuric acid, the preparation cost is relatively high, and sulfur trioxide is easily formed after the prepared sulfur-containing ammonium phosphate compound fertilizer is fertilized into the soil. The gas is emitted in the air, which not only causes the nutrient loss of the slow-release fertilizer to be lost quickly, but also causes air pollution, and the absorption of sulfur, phosphorus and nitrogen in the slow-release fertilizer by crops is limited. sulfur trioxide

A large amount of nitrogen and phosphorus elements are lost; while elemental sulfur is used as a sulfur source, the sulfur slurry is reacted with ammonium phosphate in a tubular reactor and then granulated, dried, and the product is obtained; this method is more dangerous, and the reason is that , Sulfur is a substance that is incompatible with water and does not honor most organic solvents. Therefore, it is difficult to uniformly mix sulfur in ammonium phosphate after turning it into a fluid, and the production cost is high; moreover, sulfur itself is easy Inflammable and explosive substances may burn under heating and frictional environments, and, due to the accumulation of dust in the air during the process of adding sulfur to the reaction vessel, the concentration of sulfur in the air is high, which in turn makes The production workshop is prone to explosion, reducing the safety factor of the production workshop

[0003] Not only that, in the production process of the sulfur-containing ammonium phosphate slow-release fertilizer existing in the prior art, due to the improper treatment of the sulfur element, the amount of sulfur infiltrated into the ammonium phosphate particles is small, and the prepared sulfur-containing ammonium phosphate The sulfur content of the slow-release fertilizer is low; and, due to the improper treatment of the surface of the sulfur-containing ammonium phosphate slow-release fertilizer, the prepared sulfur-containing ammonium phosphate slow-release fertilizer is easy to agglomerate and agglomerate, thereby affecting the sulfur-containing ammonium phosphate slow-release fertilizer. quality of release fertilizer