Low-tower preparation method of small-particle phosphorus-potassium nitrate fertilizer

Abstract

The invention discloses a low-tower preparation method of a small-particle phosphorus-potassium nitrate fertilizer. The small-particle phosphorus-potassium nitrate fertilizer is prepared from a nitrophosphate fertilizer and a potassium fertilizer in a mass ratio of (0.5-9): 1, wherein the nitrophosphate fertilizer comprises 15-32% of nitrogen and 4-22% of phosphorus pentoxide; the potash fertilizer is selected from potassium sulfate and potassium chloride; the potassium sulfate is powdery potassium sulfate and comprises, in percentage by mass, 45-52% of potassium oxide; and the potassium chloride is powdery potassium chloride and comprises, in percentage by mass, 55-62% of potassium oxide. The nitrophosphate fertilizer and the potash fertilizer are made into slurry, and the slurry is emulsified and granulated to obtain a small-particle product within a range of 0.5-2.5 mm. According to the invention, the height of a granulation tower can be reduced from 100 meters or more to about 30 meters; and by controlling different technical indexes such as slurry temperature, granulator specification, granulator discharging mode, granulator rotating speed and the like, the slurry is atomized and centrifugally granulated to obtain the small-particle product. The atomization centrifugal granulator disclosed by the invention is free of a blocking phenomenon, production operation is easier to control, and production continuity is stronger.

Description

technical field [0001] The invention belongs to the technical field of fertilizer preparation, and mainly relates to a low-tower preparation method of small particle phosphorus potassium nitrate fertilizer. Background technique [0002] Fertilizer, as one of the indispensable factors for plant growth, has been constantly innovating and developing. Nitrophosphate fertilizer is dark gray, neutral, highly hygroscopic, and easy to agglomerate. Water-insoluble and nitrate nitrogen in fertilizers each account for about half of the total phosphorus and nitrogen. Nitrate nitrogen is not absorbed by the soil, and it is easy to lose with water. It is better to apply it to dry land than to paddy field; on dry soil with severe phosphorus deficiency, high water-soluble nitrophosphate fertilizer should be used. In order to meet the needs of crops, other elements such as potassium can also be added, and the market demand for potassium nitrate fertilizer is relatively large. [0003] The...

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Problems solved by technology

[0010] 1. The high-tower granulation production line has high investment: the construction cost of a 110-meter cement tower is about 15 million yuan, plus the equipment investment is close to 20 million yuan;

[0011] 2. The height of the prilling tower is mostly above 100 meters, the air intake volume is large, the dust treatment is difficult, and the environmental pollution diffusion radius is large;

[0012] 3. The operation cost of raw materials transported from the ground to the top of the tower is high;

[0013] 4. Once the inner wall of the taller tower is sticky, it will be very difficult to clean the tower wall, and the unsafe factors will obviously increase

But at present there is no special production process to produce such products, such as adopting patents "Method, system and compound fertilizer for producing compound fertilizer by high tower granulation-CN108707000A", "A method for producing urea-based compound fertilizer by high tower granulation-CN102584395A ", "Method and equipment for producing granular compound fertilizer by high-tower granulation-CN1213001C" are produced by high-tower granulation technology, and the screen in the high-tower granulator is reduced from 2 to 4mm to 1 to 2mm to produce small Granular materials, but there will be the following problems: ① Impurities such as infusible matter exceeding the size of the sieve hole in the raw material will block the sieve hole or accumulate inside the sieve mesh after the sieve mesh diameter becomes smaller, resulting in frequent cleaning. Granules, rust impurities in equipment and unmelted matter produced in the pulping process, and all kinds of unmelted matter cannot be completely removed in production; ②The tower height required for the production of 0.5-2.5mm compound fertilizer particles is much lower than 1~ The tower height required for the production of 4.75mm compound fertilizer granules is about 1 / 8-1 / 3 of its height. It is a great waste to produce such products with the original high tower system

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