Determination of aluminium in iron ore and iron ore sinter by a complexometric method

A complexometric method for the determination of aluminium in iron ore and sinter products has been developed. Iron, manganese, vanadium, etc., are complexed with mercaptoacetic acid, and aluminium and other elements such as titanium, if present, are precipitated as R2O3 with hexamethylenetetramine (hexamine). The precipitate of R2O3 is dissolved in hydrochloric acid and complexed with EDTA. The excess of EDTA is titrated with standard lead solution using xylenol orange as indicator. The EDTA bound to the aluminium is released by boiling with ammonium fluoride and backtitrated with standard lead solution with xylenol orange as indicator and hexamine buffer. The method eliminates the usual solvent extraction procedure and aluminium is separated from iron, manganese, vanadium, calcium and magnesium, etc., in a single step; it takes about 1–2 h and is suitable for routine analysis.