Novel extraction crystallization method for preparing potassium sulfate crystals, fluidization device and application of fluidization device

Abstract

The invention discloses a novel extraction crystallization method for preparing potassium sulfate crystals, a fluidization device and application of the fluidization device. A fluidization method is adopted to replace stirring to generate driving force to enable crystals to grow on the surfaces of seed crystals, so that the environment is more uniform and stable, all crystal faces of the crystalsare uniformly supplied with solutes in a supersaturated solution, a solution continuously flows, the super-saturation degree of the solution in a bed is basically kept unchanged, and the obtained crystals are good in crystal form and high in quality. According to the fluidized bed fractional crystallization process production device for coupling extraction crystallization, the contact probabilityof crystals in the fluidization crystallizer and the contact probability of the crystals and the wall of the crystallizer are greatly reduced, and therefore secondary nucleation can be effectively reduced, and the crystals with a large size are obtained. Due to the application of the device, the production process is greatly simplified, the operation is coherent and convenient, a small amount of waste residues in the crystallizer are removed regularly, no three wastes are discharged, and the technological process is extremely environment-friendly.

Description

technical field [0001] The invention relates to the technical field of inorganic materials, in particular to a novel extraction and crystallization method for preparing potassium sulfate crystals, a fluidization device and applications thereof. Background technique [0002] Potassium sulfate has a relative molecular weight of 174, usually colorless or white hexagonal, orthorhombic crystals or white granular powder; chemically inactive, stable in air; melting point 1069°C, density 2.66g· cm -3 . At room temperature, the aqueous solution is neutral, with a pH of about 7; 1g of potassium sulfate is soluble in 8.3mL of water, 4mL of boiling water, and 75mL of glycerol, but insoluble in ethanol. Potassium sulfate is relatively common in chemical products and raw materials, and is widely used in various industries such as agriculture, industry, and medicine. As a potassium content (in K 2 O) is about 50%, and the sulfur content is about 18%, which is mainly applicable to the c...

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Problems solved by technology

However, most of the extraction and crystallization methods nowadays are stirred crystallization. Due to the collision force between the stirring paddle and the crystal in this system, the particle size of the final product will be affected to a certain extent, resulting in the particle size of the obtained potassium sulfate crystal being too small. Irregular crystal morphology

In industrial production, in addition to strict requirements on the purity of potassium sulfate, there are also high requirements on the particle size and morphology of potassium sulfate crystals. Potassium particles become larger, but these methods have high energy consumption, large losses, and serious dust pollution in processing sites

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