Manufacture method of particle potash fertilizer

Abstract

The invention provides a manufacture method of a particle potash fertilizer. A potash fertilizer qualified finished product with a particle size of 2-5.6mm is prepared by tabletting, drying, fragmentation, granulation and screening, with powdered potash fertilizer produced by a water-salt method as the raw material. The raw material powdered potash fertilizer has a water content less than 4.0%. A pressure roller gap of a tablet machine needs to be adjusted to control a tabletting thickness during tabletting and granulation; a depth of a roller skin pattern groove of a pressure roller is 5-8mm; a long shaft is 45-50mm; a short shaft is 35-45mm; and a pressure of a pressure roller wire is no less than 5KN / cm. A turn-over type of dryer is employed for drying with a temperature controlled lower than 220 DEG C and a water content lower than 1.5%. A roller gap of a crusher is adjusted to 3-8mm during fragmentation. After granulation, particles need to be graded; particles with a particle size less than 2mm are recovered to the tabletting step for further treatment, and particles with a particle size larger than 5.6mm are recovered to the fragmentation step for further treatment until having a qualified particle size. During screening, a first screen has a mesh count of 3-5 mesh, and a second screen has a mesh count of 17-19 mesh. Fragmented particles are granulated by a granulator to have smooth edges, so as to reduce powder generated during transportation.

Description

technical field [0001] The invention relates to the manufacture of granular potash fertilizers, which are suitable for the production of water-salt systems, and the method is especially aimed at the granulation of potash fertilizers such as potassium chloride, potassium sulfate, and potassium-magnesium sulfate fertilizers. Background technique [0002] With the wide application of technologies such as soil testing and fertilization and formula fertilization in agricultural production, the market demand for granular potassium fertilizer is increasing year by year due to its convenient application and long fertilizer effect period. [0003] At present, the domestic production methods of granular potassium fertilizer mainly include the following types: (1) Add binders (usually bentonite), water and other ineffective ingredients to powdery potassium fertilizers, and use agglomeration method (rotary disc granulator ) or extruding granulator; the defects of the method: ① adding b...

AI Technical Summary

Problems solved by technology

[0003] At present, the domestic production methods of granular potassium fertilizer mainly include the following types: (1) Add binders (usually bentonite), water and other ineffective ingredients to powdery potassium fertilizers, and use agglomeration method (rotary disc granulator ) or extruding granulator; the defects of the method: ① adding binder (usually bentonite), water and other ineffective ingredients, although it is beneficial to the granulation of potassium fertilizer, but reduces the effective potassium oxide in potassium fertilizer ② The water content of granular potassium fertilizer cannot be effectively controlled. If the water content is too large, the water hardness of granular potassium fertilizer can be reduced, and more powder will be produced during storage and transportation, which will directly affect the particle size index of granular potassium fertilizer; ③ Extrusion granulator Due to the high pressure of the press roller, the wear of the press roller is fast, and there are many equipment failures; ④The output of a single machine is low, which is not conducive to large-scale production; The disadvantages of the method: ① Dissolution, filtration, recrystallization, and drying need to be completed, resulting in high energy consumption and high cost; ② The recrystallization process is complex and difficult to control

The above two methods do not have an effective way to adjust the particle size of granular potash fertilizers.

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