A device for producing electronic-grade phosphoric acid by separator crystallization

Abstract

A device for producing electronic-grade phosphoric acid by clapboard crystallization, which is equipped with a raw material purification unit, a combustion absorption unit and a product purification unit; the raw material purification unit includes a yellow phosphorus rinsing tank, an air scrubber and a high-level phosphorus supply tank, and the combustion absorption unit includes a rectangular Tube gasification yellow phosphorus combustion furnace, main absorption tower, auxiliary absorption tower, Venturi tube, electric demister and induced draft fan, product purification unit equipment includes acid adjustment tank, arsenic removal reactor, arsenic removal filter, desulfurization tower, Partition crystallizer, desulfurization filter and product blending tank; yellow phosphorus rinsing tank, high-level phosphorus supply tank, rectangular tube gasification yellow phosphorus combustion furnace, main absorption tower, auxiliary absorption tower, acid adjustment tank, arsenic removal reactor, The arsenic filter, desulfurization tower, clapboard crystallizer, desulfurization filter and product blending tank are connected sequentially, among which the rectangular tube gasification yellow phosphorus combustion furnace is connected with the air scrubber, and the auxiliary absorption tower is connected with the Venturi tube, Electric demister and induced draft fan are connected sequentially.

Description

technical field [0001] The invention belongs to the technical field of chemical equipment, and relates to a device for producing electronic-grade phosphoric acid by crystallization of a separator. Background technique [0002] Electronic-grade phosphoric acid belongs to high-purity phosphoric acid, which is widely used in microelectronics industries such as large-scale integrated circuits and thin-film liquid crystal displays (TFT-LCD). It is mainly used for cleaning and etching chips. , Conductivity and reliability have a great influence. The ones with lower purity are mainly used for cleaning liquid crystal panel components, and the ones with higher purity are mainly used for cleaning and etching in the production process of electronic chips. Since insoluble solid particles or metal ions may be in the The current is conducted between the tiny circuits to make it short circuit, so electronic grade phosphoric acid has strict requirements on the content of insoluble solid par...

AI Technical Summary

Problems solved by technology

This method operates at extremely low temperature, consumes a lot of energy, and requires pretreatment of raw materials to remove arsenic. The operation time is long, the production cost is high, and the yield is low.

[0006] Chinese patent 201010100473.0 uses flow chromatography crystallization method to prepare high-purity phosphoric acid, and adopts external sound field to crystallize, which requires extremely high purity of raw materials (the concentration of main impurity ions is less than 1.7mg / L, and requires microporous membrane filtration), so it is difficult to apply Larger, not easy to industrialize

However, the concentration of Na, Al, Mg, Cr and other ions in the electronic grade phosphoric acid prepared by this method is relatively high (1.79mg / L, 0.94mg / L, 0.49mg / L, 0.37mg / L), which cannot meet the needs of users who are increasingly updating still needs to be further improved

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