Chemical Conversion of Anhydrous Hydrogen Fluoride for Safe Disposal

Technical Report · Tue Jun 19 00:00:00 EDT 2018

DOI:https://doi.org/10.2172/1455316· OSTI ID:1455316

Blake, Thomas A. ^[1]; Brauer, Carolyn S. ^[1]; Bachmann, Jr., William J. ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

A procedure for the safe conversion of a small (~ 1 gram) quantity of anhydrous hydrogen fluoride to calcium fluoride is described. The purpose of the conversion is to put the toxic, corrosive, gaseous compound into a chemical form that is a less toxic solid (calcium fluoride) and easier to dispose of. The hydrogen fluoride, which was contained in a 50 cc metal sample cylinder, was drawn by a small mechanical vacuum pump through an all-metal gas manifold and into a metal trap containing alternating layers of calcium oxide powder and Teflon turnings. The anhydrous hydrogen fluoride reacts with the calcium oxide to produce calcium fluoride and water vapor. Because some of the calcium oxide powder was drawn out of the trap and into the vacuum tubing, it was not possible to quantify the amount of anhydrous hydrogen fluoride converted to calcium fluoride. However, it was noted that there was a temperature rise in the trap when the gas was flowing through it, and no HF gas was detected at the vacuum pump exhaust at this time using a colorimetric Dräger tube. The trap was sealed and disposed of as solid chemical waste.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1455316
• Report Number(s): PNNL-27584
• Country of Publication: United States
• Language: English