Determination of the Stability Constants of a Number of Metal Fluoride Complexes and Their Rates of Formation

摘要

The stability constants of the fluoride complexes of Al exp +3 , H sub 3 BO sub 3 , Cr exp +3 , Cr exp +6 , Fe exp +3 , Gd exp +3 , Nb exp +5 , UO sub 2+2 , and Zr exp +4 were determined in 0.96 and 2.88 M HNO sub 3 solutions in the temperature range 25 to 60 exp 0 C with a fluoride specific ion electrode. These data can be used to calculate the concentration of chemical species in solution and will be used to correlate solution properties with solution composition. The solubilities of some fluoride precipitates were also measured in nitric acid solutions. The rates of formation of the fluoborates, aluminum fluoride, and zirconium fluoride complexes were measured with a fluoride specific ion electrode at 25, 35, and 45 exp 0 C. The rates of formation of all complexes, except BF sub 4- , AlF exp +2 , and a fluoride complex with aluminum containing more than three fluorides associated with it, were too fast to measure with the instrumentation used. (ERA citation 04:056974)