Preparation method of spherical particles of potash magnesium sulphate fertilizer

Abstract

The invention discloses a preparation method of spherical particles of a potash magnesium sulphate fertilizer. The method comprises the following steps: taking a refined soft potash magnesium sulphatefertilizer with the free water content of about 17%, and uniformly mixing the refined soft potash magnesium sulphate fertilizer with return scraps with the particle size of less than 2mm and the freewater content of 1.1% according to the mass part ratio of 9: 1 to obtain a mixture with the free water content of about 15.1%; sequentially feeding the mixture into a spiral pipe type shaping machineand a disc granulator, and screening to obtain spherical potassium-magnesium fertilizer particles; evenly forming a plurality of round pits with the diameter of 4 cm and the depth of 0.5 cm in the disc face of the disc granulator granulation disc side by side in a central symmetry mode, every two round pits being externally tangent, vertically arranging a silica gel column with the height of 4 cmand the diameter of 1 cm at the vertex of an inscribed regular triangle of each round pit close to the outer periphery of the granulation disc, arranging a hot air pipe over the second-layer disc face, enabling the material temperature to be 70-80 DEG C by hot air, enabling the particles obtained on the second-layer tray surface to enter a third-layer receiving tray, further drying the particlesto obtain potassium-magnesium fertilizer spherical particle finished products with free water of less than or equal to 1.5%, and obtaining the potassium-magnesium fertilizer spherical particles with the particle size of 2-4.5 mm after screening.

Description

technical field [0001] The invention relates to a preparation method of spherical particles of potassium magnesium sulfate fertilizer. Background technique [0002] At present, there are three main production methods of granular fertilizers: extrusion method, pellet method and slurry method. [0003] The process of extrusion granulation is simple, relying on the action of mechanical extrusion to extrude powdered raw materials into granules, strips or flakes. This method has simple process and high granule strength, but its disadvantages are: irregular product granules, inconvenient use of machine sowing, rough surface of granules, and easy powder loss during transportation. [0004] The granulation method is currently the most commonly used method for compound fertilizer granulation. The granulation method adjusts the water content of the raw material mixture to make it reach the liquid phase amount required for granulation, and forms a particle mixture with a certain part...

AI Technical Summary

Problems solved by technology

This method is simple in process and high in particle strength, but its disadvantages are: irregular product particles, inconvenient use of machine sowing, rough surface of particles, and easy powder loss during transportation

Using the whole slurry method, the appearance of the product particles is more round and smoother, but the one-time investment of this process is relatively large, so its popularization and application are subject to certain restrictions

[0006] Domestic potassium and magnesium sulfate fertilizer granulation is mainly extrusion granulation method, the production process is dusty, the equipment failure rate is high, the maintenance cost is high, the molding rate is low, the appearance of the product is irregular, and most of the output is low

Due to the high production cost, the addition of additives, the product nutrients do not meet the requirements of national standards, or the low particle strength, there are only a handful of enterprises that produce spherical potassium magnesium sulfate fertilizer particles.

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