Rectification device for preparing electronic grade hydrogen fluoride

Abstract

The invention relates to the technical field of fluorine chemical engineering, in particular to a rectification device for preparing electronic grade hydrogen fluoride. The rectification device for preparing the electronic grade hydrogen fluoride is characterized in that a circulating fluidized bed distillation tower body is divided into an upper section and a lower section; the upper part of thecirculating fluidized bed distillation tower body is a rectification section; the lower part of the circulating fluidized bed distillation tower body is a stripping section; a multi-stage hydrocycloneseparating condenser is designed on the rectification section to achieve purposes that gas and liquid are separated through cyclone, a liquid film is prone to be formed on the internal wall of a cylinder body, and rising steam and the downflow liquid film transfer mass to each other; and a constant temperature reboiler is designed on the stripping section.

Description

technical field [0001] The invention relates to the technical field of fluorine chemical industry, in particular to a rectification device for preparing electronic grade hydrogen fluoride. Background technique [0002] Electronic grade hydrogen fluoride is mainly used as a cleaning agent and etchant in photovoltaics, integrated circuits and other industries, and is one of the key auxiliary materials in these industries. Since the impurity arsenic has a serious impact on the performance of electronic devices, the removal of arsenic is the purification of hydrogen fluoride. The key technology is to use an oxidant to oxidize trivalent arsenic to a high-boiling pentavalent arsenic compound, and then use the difference in volatility to remove it by distillation. Chinese invention patent (patent number CN201110276860.4, patent name is a method for preparing electronic grade hydrofluoric acid) discloses a method for preparing electronic grade hydrofluoric acid, including the follow...

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Problems solved by technology

[0003] Prior art 1 uses fluorine gas as an oxidant to oxidize impurities in hydrogen fluoride, and removes high boiling substances such as HAsF by washing and rectifying methods 6 , MAsF 6 、H 2 SO 4 、H 2 O, H 2 SiF 6 、H 3 PO 4 etc. and volatile component SO 2 、SiF 4 、PF 3 、POF 3 , AsF 5 , SF 6 、PF 5 etc., the problems still to be solved are, first, fluorine gas is highly toxic, highly chemically active and strong oxidizing, and it is difficult to solve the sealing problem of existing conveying machinery such as circulating pumps, and serious safety accidents are likely to occur if leakage occurs; , the integration of rectification and washing in a rectification tower does not meet the technical specifications; prior art 2 points out that the impurity arsenic in hydrogen fluoride has a serious impact on the performance of electronic devices, and the removal of arsenic is a key technology for the purification of hydrogen fluoride. The method commonly used in the prior art is to use an oxidant to oxidize trivalent arsenic to a high-boiling point pentavalent arsenic compound, and then use distillation to remove it. The oxidant is usually potassium permanganate, hydrogen peroxide, potassium dichromate, etc. The problems to be solved are: first, the introduction of other impurities increases the difficulty and cost of subsequent treatment; second, the oxidation time is longer, generally reaching 6 to 48 hours, and the energy consumption is higher

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