Method for removing arsenic from electronic grade phosphoric acid generated by wet-process phosphoric acid

A technology of electronic grade phosphoric acid and wet phosphoric acid, applied in chemical instruments and methods, phosphorus compounds, inorganic chemistry, etc.

Active Publication Date: 2012-10-03
WENGFU (GRP) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there are three types of phosphoric acid purification and purification methods in China, namely, ion exchange method, chemical purification method, and physical purification method. In production practice, it is difficult to remove As

Method used

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  • Method for removing arsenic from electronic grade phosphoric acid generated by wet-process phosphoric acid
  • Method for removing arsenic from electronic grade phosphoric acid generated by wet-process phosphoric acid

Examples

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Embodiment

[0023] A factory adopts the technology of the present invention to remove arsenic in the production process of electronic grade phosphoric acid, and the specific scheme is as follows:

[0024] ① Add H to the arsenic removal reactor 2 S and phosphoric acid, and keep the reaction temperature at 80°C, and stir;

[0025] ② Filter the concentrated liquid from the arsenic removal reactor through a filter to separate the arsenic residue from the clear liquid;

[0026] ③ After the clear liquid is heated to a certain temperature, use a pump to inject H to remove 2 The S tower uses air bubbling and negative pressure suction to blow off the residual hydrogen sulfide gas in the acid; 2 The acid flow rate of the S tower is stable, the temperature of the preheating acid entering the tower is stable, and the amount of stripping air is stable;

[0027] ④ take off H 2 S acid enters the storage tank through a microfilter for standby, ensuring that the arsenic content of low arsenic acid is...

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Abstract

The invention discloses a method for removing arsenic from electronic grade phosphoric acid generated by wet-process phosphoric acid. The method comprises the following steps of: firstly, adding H2S and phosphoric acid in an arsenic-removed reactor and maintaining the reaction temperature at 80 DEG C for stirring; secondly, filtering concentrated liquor from the arsenic-removed reactor through a filter to separate arsenic slag from clear solution; thirdly, after the clear solution is heated to a certain temperature, pumping the heated clear solution into an H2S-removing tower and blowing to remove residual hydrogen sulfide gas in the acid by using an air bubbling and negative-pressure sucking mode; fourthly, enabling the acid subjected to H2S removal to enter a storage groove for later use by a microstrainer and ensuring that the arsenic content of low arsenic acid to reach below 1mu g / g and controlling the granularity to below 5mu m; and fifthly, absorbing H2S gas blown in the arsenic-removed process with Na2CO3, wherein the obtained Na2S solution is used for producing phosphate with low sulfur content requirement. According to the method disclosed by the invention, the arsenic in the phosphoric acid can be effectively removed and the industrial standard is reached.

Description

technical field [0001] The invention relates to a technology for producing electronic-grade phosphoric acid by wet-process phosphoric acid, in particular to a method for removing arsenic from electronic-grade phosphoric acid produced by wet-process phosphoric acid. Background technique [0002] Electronic-grade phosphoric acid is high-purity phosphoric acid, which is one of the ultra-clean and high-purity reagents. It is widely used in large-scale integrated circuits (IC), thin film liquid crystal displays (TFT-LCD), semiconductors and other microelectronic industries. The purity and cleanliness of cleaning and etching agents have a very important impact on the yield, electrical performance, and reliability of electronic components. [0003] When producing electronic components and circuits with stable electrical characteristics and reliability, the chemical reagents used to process silicon wafers are required to be very pure. Insoluble solid particles or metal ions may cond...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B25/237
Inventor 孟文祥吴松
Owner WENGFU (GRP) CO LTD
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