[Chemical Knowledge]：Production and manufacturing method and process of phosphate

Research on
manufacturing methods of phosphate
Abstract

This paper introduces in detail the manufacturing methods of phosphate in the field of raw materials for chemical production. By comparing the process of wet-process phosphoric acid, thermal phosphoric acid process and fluorosilicic acid process, the advantages and disadvantages of various methods are summarized, and the effects of reaction principle, process flow, equipment selection, operating conditions and other factors on phosphate manufacturing are discussed. The experimental results show that the preparation of phosphate by wet-process phosphoric acid process has good economic benefits and environmental friendliness, which provides an important reference for industrial production.

1. Introduction

phosphate is an important class of chemicals, widely used in food, medicine, agriculture, metallurgy and other fields. With the continuous growth of market demand, it is of great significance to study the manufacturing methods of phosphate for improving production efficiency, reducing costs and reducing environmental pollution. In this paper, several common phosphate manufacturing methods are discussed in depth, aiming to provide theoretical guidance for practical production.

2. Wet-process phosphoric acid process

Wet-process phosphoric acid is the reaction of phosphate rock with sulfuric acid to produce a mixture of phosphoric acid and calcium sulfate, and then through filtration, concentration, crystallization and other steps to produce phosphate. The process has the advantages of simple equipment, convenient operation and low cost, but it produces more waste residue and needs to be properly treated.

2.1 reaction principle

wet process phosphoric acid process is the main reaction:

3Ca3(PO4)2 4H2SO4 → 3Ca(H2PO4)2 3 CaSO4

2.2 process

phosphate ore after crushing, grinding mixed with sulfuric acid, in the reaction kettle for reaction. After the reaction is completed, a mixture of phosphoric acid and calcium sulfate is obtained by filtration, and then the mixture is concentrated, crystallized, and centrifuged to obtain a phosphate product.

2.3 equipment selection and operating conditions

reactor can choose glass lined reactor or stainless steel reactor, with corrosion resistance, easy to clean and so on. The operating conditions need to control the reaction temperature, sulfuric acid concentration, phosphate rock particle size and other factors to ensure the smooth progress of the reaction.

3. thermal phosphoric acid process

thermal phosphoric acid process is through the electrolysis of phosphate rock to obtain phosphorus and oxygen, and then phosphorus and steam reaction to generate phosphoric acid. The process has the advantages of high product quality and no waste residue, but the energy consumption is high.

3.1 reaction principle
The main reaction of
thermal phosphoric acid process is:

2 Ca3(PO4)2 6SiO2 10C → 6 CaSiO3 P4 10CO
P4 5O2 → P4O10
P4O10 6H2O → 4 H3PO4

3.2 process

phosphate rock is crushed, dried, mixed with coke and quartz sand, and electrolyzed in a high-temperature electric arc furnace. The generated phosphorus vapor reacts with steam to generate phosphoric acid, which undergoes condensation, crystallization and other steps to obtain a phosphate product.

3.3 equipment selection and operating conditions

electric arc furnace can choose high-efficiency energy-saving electric arc furnace, and equipped with advanced phosphorus vapor recovery system to improve resource utilization. The operating conditions need to control the electrolysis temperature, current intensity, burden ratio and other factors to ensure the electrolysis efficiency and product quality.

4. Process
of phosphate production by fluosilicic acid method
phosphate production by fluosilicic acid method is the use of fluosilicic acid and phosphate rock powder reaction to generate phosphoric acid and calcium fluoride, and then through filtration, concentration, crystallization and other steps to produce phosphate. The process has the advantages of easy access to raw materials and mild reaction conditions, but the resulting calcium fluoride waste needs to be properly treated.

the principle of 4.1 reaction

the main reaction of fluorosilicic acid method to produce phosphate is:

Ca5(PO4)3F 7H2SO4 → 3H3PO4 7CaSO4 HF

4.2 process

The phosphate rock powder and fluorosilicic acid are mixed and reacted in a reactor. After the reaction is completed, a mixture of phosphoric acid and calcium fluoride is obtained by filtration, and then the mixture is concentrated, crystallized, and centrifuged to obtain a phosphate product.

4.3 equipment selection and operating conditions

reactor can choose glass lined reactor or stainless steel reactor, and equipped with calcium fluoride waste residue treatment system. The operating conditions need to control the reaction temperature, acidity, phosphate rock powder particle size and other factors to ensure the smooth progress of the reaction.

5. Experimental results and analytical

By comparing the process of wet-process phosphoric acid, thermal phosphoric acid process and fluorosilicic acid process to produce phosphate, it is found that the wet-process phosphoric acid process has good economic benefits and environmental friendliness. In the course of the experiment, the yield and purity of phosphate were further improved by optimizing the reaction principle, process flow, equipment selection and operating conditions.

6. Conclusion

This paper studies the manufacturing methods of phosphate in the field of chemical production raw materials, including wet-process phosphoric acid process, thermal phosphoric acid process and fluorosilicic acid process to produce phosphate. Through comparative analysis, it is found that the wet-process phosphoric acid process has good economic benefits and environmental friendliness, which provides an important reference for industrial production. In the actual production process, the appropriate manufacturing method should be selected according to the specific needs and conditions, and the process flow and equipment selection should be further optimized to improve production efficiency, reduce costs, and reduce environmental pollution.