Circulating fluidized bed decomposition crystallization device and decomposition crystallization method

Abstract

The invention discloses a circulating fluidized bed decomposition crystallization device and a decomposition crystallization method. The circulating fluidized bed decomposition crystallization devicecomprises a decomposition crystallization device body; a mother liquor overflow groove is formed in the upper part of the decomposition crystallization device body; an inner guide cylinder and an outer guide cylinder are arranged in the decomposition and crystallization device body; a crystal slurry discharge pipeline is arranged at the lower part of the decomposition and crystallization device; aliquid supplementing opening is formed in the bottom of the decomposition and crystallization device body, a main stirring device is arranged in the decomposition and crystallization device body, a stirring shaft and blades of the main stirring device extend into the inner guide cylinder, and a liquid distribution plate is arranged in the decomposition and crystallization device body and locatedbetween the crystal slurry discharge pipeline and the liquid supplementing opening; the invention further comprises the circulating fluidized bed decomposition and crystallization method. The decomposition and crystallization method can be used for preparing potassium chloride through carnallite decomposition and crystallization and can also be used for crystallization production of potassium sulfate through potassium chloride and sulfate double decomposition and crystallization, the height-diameter ratio of the decomposition and crystallization device is reduced, the raw material entrainmentrate is reduced, and meanwhile the average particle size of the product can be increased.

Description

technical field [0001] The invention relates to a circulating fluidized bed, in particular to a circulating fluidized bed decomposing and crystallizing device and a decomposing and crystallizing method. Background technique [0002] my country is a large agricultural country and has a large demand for potash fertilizers. However, the output of my country's potash salt industry is far from meeting the needs of agriculture. Nearly 50% of potash salt still needs to be imported from abroad, and the dependence on foreign countries is extremely high. [0003] The decomposition and crystallization device commonly used in the potassium salt industry is a variant of the DTB type decomposition and crystallization device in the development of the potassium salt industry. It is mainly used for the dissolution and crystallization of low-sodium carnallite to prepare potassium chloride and double salt and chlorine containing magnesium sulfate. Potassium sulfate is prepared by metathesis of...

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Problems solved by technology

[0004] CN2678736Y discloses a push-up and lift-down mixed decomposition type crystallizer, and CN103073030B discloses a decomposition and crystallization device for hydrolyzing carnallite, but none of them focuses on solving the relative separation of crystallization raw materials and crystallization products during crystallization production , and does not solve the problem of circular crystallization of large particle raw materials; CN105597363B discloses a mechanical decomposition and crystallization device for potassium salt industry. The bottom of the inner cylinder is provided with a bowl-shaped baffle to reduce the entrainment of raw materials in the product, but the structure of the baffle It is easy to form a "dead zone" for material accumulation on the lower side of the stirring shaft, occupying the internal space of the decomposition and crystallization device to form an inefficient area, and once the "dead zone" is formed, the existence of the bowl-shaped baffle will no longer be able to prolong the undissolved The purpose of raw material residence time; CN110229024A discloses a kind of decomposition crystallizer for potassium salt industry, introduces liquid distribution device and diversion cone in the middle and lower part of the crystallizer, and introduces the mode of local upward flow in the crystallizer to reduce the entrainment of raw materials in the product , but the device requires a large amount of mother liquid circulation during normal operation, and the existence of the liquid distribution device and the diversion cone will greatly increase the aspect ratio of the device

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