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

The manufacturing method
of phosphate fertilizer
phosphate fertilizer is a fertilizer with phosphorus as the main nutrient, which plays an important role in the field of raw materials for chemical production. Common phosphate fertilizer manufacturing methods are thermal, wet and mixed methods. This article will introduce these three manufacturing methods and their process flow in detail.

1. thermal method to manufacture phosphate fertilizer

thermal method to manufacture phosphate fertilizer is mainly through high temperature reaction of phosphate rock, sulfuric acid and silica and other raw materials into phosphate fertilizer. The specific process is as follows:

1. Crushing and grinding of phosphate rock: the phosphate rock is crushed to a certain particle size, and then ground to make it fully contact with sulfuric acid.
2. Acidolysis reaction: mix the ground phosphate rock with sulfuric acid and carry out acidolysis reaction at high temperature to generate phosphoric acid and calcium sulfate.
3. Filtration and washing: The reacted mixture is filtered to separate phosphoric acid and calcium sulfate, and then the phosphoric acid is washed to remove impurities.
4. Neutralization reaction: The washed phosphoric acid is neutralized with an alkaline absorbent to generate a phosphate.
5. Drying and crushing: The generated phosphate is dried and crushed to obtain phosphate fertilizer products.

2. wet process manufacturing phosphate fertilizer

wet process manufacturing phosphate fertilizer is by reacting phosphate rock with sulfuric acid to generate phosphoric acid, and then reacting with alkaline absorbent to generate phosphate. The specific process is as follows:

1. Grinding of phosphate rock: Grinding phosphate rock to a certain particle size to make it fully contact with sulfuric acid.
2. acidolysis reaction: mix the ground phosphate rock with sulfuric acid and carry out acidolysis reaction at room temperature to generate phosphoric acid and calcium sulfate.
3. Filtration and washing: The reacted mixture is filtered to separate phosphoric acid and calcium sulfate, and then the phosphoric acid is washed to remove impurities.
4. Neutralization: The washed phosphoric acid is neutralized with an alkaline absorbent to generate a phosphate solution.
5. Concentration and Crystallization: The phosphate solution is concentrated to a supersaturated state, and then cooled and crystallized to obtain phosphate crystals.
6. Centrifugal Separation and Drying: The crystallized mixture is centrifuged to separate the phosphate crystals and the mother liquor, and then the phosphate crystals are dried to obtain the phosphate fertilizer product.

3. mixing method to manufacture phosphate fertilizer

mixing method to manufacture phosphate fertilizer is a combination of thermal method and wet method, first phosphate rock and sulfuric acid reaction to produce phosphoric acid, and then phosphoric acid and alkaline absorbent reaction to produce phosphate. The specific process flow is as follows:

1. grinding and acidolysis of phosphate rock: grinding phosphate rock to a certain particle size, mixed with sulfuric acid at high temperature acidolysis reaction, the generation of phosphoric acid and calcium sulfate.
2. Filtration and washing: The reacted mixture is filtered to separate phosphoric acid and calcium sulfate, and then the phosphoric acid is washed to remove impurities.
3. Neutralization: The washed phosphoric acid is neutralized with an alkaline absorbent to generate a phosphate solution.
4. Concentration and Crystallization: The phosphate solution was concentrated to a supersaturated state, and then cooled and crystallized to obtain phosphate crystals.
5. Centrifugal separation and drying: The crystallized mixture is centrifuged to separate phosphate crystals and mother liquor, and then the phosphate crystals are dried to obtain phosphate fertilizer products.

of the above three methods can be used to manufacture phosphate fertilizer, the specific choice of which method depends on the source of raw materials, production costs and product quality and other factors. No matter which method is adopted, it is necessary to strictly control the process flow and product quality to ensure that the phosphate fertilizer produced meets national standards and requirements.

In short, the manufacturing method of phosphate fertilizer is of great significance to the field of chemical production raw materials, and mastering the manufacturing method and process flow can improve the production efficiency and product quality, and contribute to the development of agricultural production and chemical industry.