Determination of boron in ores of the element such as borax and ulexite.
Ores of boron such as borax and ulexite may be decomposed by acid digestion to yield boric acid. Acidic solutions of fluoride react exothermically with boric acid according to the equations:
To form HBF4, boric acid will decompose metal-fluoride complexes, and thus the determination of boric acid by fluoride is not affected by the presence of metals in solution. The titration of boric acid by fluoride also permits determination of boric acid independent of other acidic substances in the solution.