A RAPID METHOD FOR THE CHEMICAL CHARACTERIZATION OF ILMENITES USING ICP-OES

The principal use of titanium minerals (around 90% of the total) is fo r the production of titanium dioxide pigment. The analysis of the feed stock for the production of pigment with respect to Mn, Mg, Ca, Al, C r, and V as impurities plays a vital role in the sulfate or chloride l eaching processes. Hence a simple, expeditious, and precise method has been developed for the dissolution of ilmenite samples, followed by c hemical analysis. The sample dissolves in phosphoric acid within 15-20 minutes of boiling, resulting in a clear soluttion. The TiO2 and Fe2O 3 (total) contents are determined in the diluted solutions and Mg, Mn, Ca, Al, Cr, and V in the original solution by ICP-OES at the emission wavelengths free from matrix interferences. The validity of the analy tical data obtained was tested by comparing the data of the sample sol ution obtained with KHSO4 fusion and with microwave digestion using HF , HNO3, and HCl. The advantages and disadvantages of these methods are discussed in detail. The phosphoric acid dissolution method is the pr eferred method due to speed, simplicity, and total dissolved salts and offers a relative standard deviation of 0.2 to 0.5% for major and 1 t o 5% (n=s) for minor constituents.