CN1168874A

CN1168874A - Process for producing compound fertilizer contg. potassium sulfate and ammonium phosphate

Info

Publication number: CN1168874A
Application number: CN 97105690
Authority: CN
Inventors: 李守义; 王健平; 王金凯
Original assignee: 李守义
Priority date: 1997-02-19
Filing date: 1997-02-19
Publication date: 1997-12-31

Abstract

The invented technology is that concentrated sulfuric acid reacts with potassium chloride to produce potassium hydrogen sulfate solution, which is mixed with ammonium phosphate powder to obtain compound thick liquid, after neutralizing with ammonia, urea is added to obtain compound thick liquid containig potassium sulphate, ammonium phosphate and urea, then the liquid is sprayed and pelletized to produce high concn. nitrogen, phosphorus and potassium compound pertilizer.

Description

Process for producing potassium sulfate phosphorus ammonia compound fertilizer

The invention belongs to the technical field of chemical industry. The process for producing potassium sulfate-ammonium phosphate compound fertilizer is a process for preparing nitrogen, phosphorus and potassium three-element high-concentration compound fertilizer.

At present, the production process for producing the nitrogen, phosphorus and potassium three-element high-concentration agricultural fertilizer at home and abroad mainly comprises two types:

1. chemical synthesis process, namely a process for producing a nitrogen, phosphorus and potassium three-element high-concentration fertilizer, which is called chemical synthesis method, and theproduced fertilizer is usually called compound fertilizer; the process has the advantages of large investment and low cost.

2. A physical synthesis process method, namely a process for producing a nitrogen, phosphorus and potassium three-element high-concentration fertilizer, which is called a physical synthesis method, and the produced fertilizer is usually called a compound fertilizer; the process has the advantages of low investment and high cost.

The invention aims to provide a production process method of a nitrogen, phosphorus and potassium three-element high-concentration compound fertilizer with low investment and low production cost from the actual production, which has partial chemical synthesis and partial physical synthesis, so that the process is called a compound fertilizer production process method. The fertilizer produced by the process is called compound fertilizer, the proportion of the three elements is convenient to regulate and control, the quality is ensured, the production cost is low, and the appearance quality of the product is good.

A process for preparing the composite fertilizer of potassium sulfate-ammonium phosphate includes such steps as mixing potassium bisulfate with powdered ammonium phosphate at 70-90 deg.C, stirring to obtain mixed slurry, neutralizing with ammonia to obtain pH value in the range of 5-6, adding urea to increase nitrogen content, and spray granulating.

The chemical reaction and physical synthesis process in the above process is as follows:

wherein HCi enters a circulating tower to prepare dilute hydrochloric acid.

2, physical mixing process:

KSO₄+KHSO₄aqueous solution + solid NH₄H₂PO₄→ formation of a slurry of the mixture during stirring at a temperature of 70 to 90 ℃.

3, a neutralization process:

and (4) compounding the slurry.

In the chemical reaction and physical process, no matter the relationship between various substances, only the proportional relationship that the proportional contents of the three elements of diazo, phosphorus and potassium respectively reach 15 percent of the total amount is noted.

The invention realizes that the potassium bisulfate liquid slurry obtained by the common process method is mixed with the powdery solid ammonium phosphate after being crushed, and then the mixture is neutralized by ammonia, and part of solid urea is added to prepare the liquid slurry which is granulated by spraying to obtain the nitrogen, phosphorus and potassium three-element high-concentration compound fertilizer.

Claims

A process method for producing a nitrogen, phosphorus and potassium three-element compound fertilizer by physically stirring a potassium bisulfate aqueous solution and solid powdery ammonium phosphate. The method is characterized in that concentrated sulfuric acid and potassium chloride are reacted at the temperature of 92-110 ℃ to generate potassium bisulfate solution, the potassium bisulfate solution is dissolved in water, the potassium bisulfate solution and the solid powdery ammonium phosphate are physically mixed in the stirring process, ammonia is neutralized, partial solid urea is added to prepare nitrogen, phosphorus and potassium three-element composite liquid slurry, and the nitrogen, phosphorus and potassium three-element high-concentration compound fertilizer is obtained by spraying and granulating.
The process for producing a high-concentration compound fertilizer containing three elements of nitrogen, phosphorus and potassium by physically mixing an aqueous solution of potassium bisulfate with solid powdery ammonium phosphate in the stirring process according to claim 1, wherein the crushed powdery ammonium phosphate is subjected to physical mixing gradually in the continuous stirring process while the aqueous solution of potassium bisulfate is kept at a temperature of 80-90 ℃, thereby forming a slurry of a mixed aqueous solution of potassium bisulfate and ammonium phosphate.
The process of producing high concentration composite fertilizer of three elements of ammonia, phosphorus and potassium with the mixture of potassium bisulfate solution and solid powdered ammonium phosphate as set forth in claim 1 includes the steps of neutralizing the slurry of potassium bisulfate and ammonium phosphate obtained from chemical reaction with ammonia, adding urea to obtain three-element slurry, spraying slurry and pelletizing to obtain high concentration composite fertilizer of three elements of nitrogen, phosphorus and potassium.