ONE-STEP MICROWAVE DIGESTION PROCEDURES FOR THE DETERMINATION OF ALUMINUM IN STEELS AND IRON-ORES BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

The use of microwave ovens for the dissolution of samples is widesprea d and has made it possible to obtain results very rapidly giving preci sion and accuracy identical with, or better than, than that obtained b y classical procedures. Technical publications and instruction manuals , however, rarely give information on the dissolution of insoluble com pounds in acids such as, for example, compounds of aluminium the deter mination of which in iron and steel is important in iron and steel ind ustrial laboratories. Procedures are proposed for the dissolution of a luminium in iron ores and steels; the procedures were tested using cer tified reference materials. For steels, dissolution is accomplished fa r faster than with classical procedures. Preliminary dissolution tests on pure alumina, under controlled temperature and pressure conditions , were necessary in order to determine the optimum conditions for the dissolution of iron ores. Complete dissolution of an iron ore sample t akes approximately 90 min.