Sub-boiling distillation method for high-purity hydrochloric acid

Abstract

The invention relates to a sub-boiling distillation method for high-purity hydrochloric acid. The sub-boiling distillation method comprises the following steps: taking hydrochloric acid from a fluorocarbon alkane production device as a raw material, carrying out membrane type distillation operation in a determined sub-boiling distillation device, controlling process parameters such as a preheating temperature, a heating temperature, a condensing temperature and a circulating flow rate to prepare the high-purity hydrochloric acid with concentration greater than 35.0% and metal ion content smaller than 1ppb, wherein indexes of the metal ions satisfy Semi-C8 standards proposed by the Semiconductor Equipment and Material International). The sub-boiling distillation method can be used for solving a problem of removing metal ions in super clean high-purity hydrochloric acid, and also can be used for effectively improving the distillation rate at the same time.

Description

technical field [0001] The invention relates to a sub-boiling distillation method of high-purity hydrochloric acid. Background technique [0002] Ultra-clean and high-purity reagents (Process Chemicals) are one of the key basic chemical materials in the microelectronics industry, especially in the production process of ultra-large-scale integrated circuits. They are mainly used for chip cleaning and corrosion. Yield, electrical performance and reliability all have a very important impact. Ultra-clean high-purity hydrochloric acid is one of the most demanding ultra-clean reagents and a product with high added value. [0003] The purification technologies of ultra-clean and high-purity reagents include the following: distillation and rectification, isothermal distillation, subboiling distillation, vacuum distillation, sublimation, chemical treatment technology, gas absorption technology, particle control technology, etc. The control indicators of ultra-clean and high-purity ...

AI Technical Summary

Problems solved by technology

[0005] Other related technologies such as: CN102874757A discloses a preparation method of high-purity hydrochloric acid, using industrial hydrochloric acid as a raw material, and preparing high-purity hydrochloric acid that meets HG / T2778-2009 industry standards through evaporation, ultrafiltration, absorption, sub-boiling distillation and other processes. Pure hydrochloric acid; Henan Chemical Industry [2010, 27 (7), 61-62] through the process improvement of industrial hydrochloric acid preparation equipment, the concentration of industrial hydrochloric acid prepared is greater than 36.0%, Fe is less than 3mg / L; Shanghai Chlor-Alkali Chemical Industry [2006, (1), 13-17] The traditional sub-boiling distillation process was optimized, and the concentration of the prepared hydrochloric acid could reach 36-38%, and the metal ion content was less than 0.1ppb, reaching the requirements proposed by the International Semiconductor Equipment and Materials Organization (SEMI). Semi-C12 standard, but the distillation rate is slow and can only reach 150-200ml / hour

Images