Fluorine handling

Fig. 3. (a) Diagram of fluorine-handling apparatus. (b) Fluorine reactor systems. 

Since fluorine and most volatile fluorides are corrosive and highly toxic, the vacuum rack for a fluorine handling system generally is placed in a hooded enclosure (Fig. 10.20) and the fluorine tank is often enclosed in a separate enclosure which can be manipulated remotely (Fig. 10.21). 

While the chemical resistance varies somewhat, stainless steel is fairly resistant to most acids and bases, is not amalgamated by mercury, and is generally resistant to oxidizing agents. While it can be used in fluorine handling, Monel and nickel are much better for this purpose. The resistance of stainless steel to atmospheric corrosion is an advantage in vacuum work because a corroded surface tends to outgas. 

A vacuum pump should be scrupulously protected from corrosive vapors and materials which will be absorbed in the pump oil or condense in the pump. For most laboratory operations a low-temperature trap is employed for this purpose, and in the case of fluorine handling systems a soda-lime trap is used to neutralize the corrosive gases. Despite these precautions, the pump oil does eventually break down and become contaminated. Regular oil changes should be scheduled for a pump at about yearly intervals for a well-protected pump and more often for pumps which are not well protected. 

Various types of pressure transducers with digital readout are available with metal interior construction. These have become quite popular for fluorine-handling systems and the like. A description of some of the common types is given in Chapter 7. 

Apparatus. Reactions using HF were carried out in translucent fluorocarbon polymer tubing (FEP)(CHEMPLAST Inc., Wayne NJ 07470) heat sealed at one end and joined via compression fittings to a Teflon valve to a metal vacuum line equipped for fluorine handling as previously described [6,17]. 

A. Apparatus and Technique. A metal vacuum line, fluorine handling equipment, bomb reactors, and valves were as previously described, " in the experimental work involving aHF, the apparatus was constructed from FEP tubing (CHEMPLAST, Inc., Wayne NJ 07470). The commonly used reactor was constructed from two /i in,... 

Apparatus. The apparatus used was very straight forward and simple. A typical fluorine handling apparatus was used as shown in Figures 1 and 2. Items one and two are fluorine and helium sources respeceively. Item three is a Hastings-Raydist model LF50... 

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