Input control of the fused magnesia powders for the needs of the energy industry

DOI: 10.62564/M4-VS1146

Victor Garbuz, Vera Sydorenchuk, Volodymyr Kolomiiets, Lyudmila Kuzmenko, Tatiana Silinska, Nataliia Ulianchych, Larisa Romanova

Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine


Measurement of the composition of materials by instrumental methods, including refractory ones, from 100% to ppb is described by the formula of relative deviations (RSD) of Horwitz [1]. In the area of the base, the measurement error can be ±4.0%. For impurities at the ppb level, it is ±50-60%. A widely used method of X-ray fluorescence analysis provides measurement of chemical elements, usually starting with Mg. An error in the measurement of the base of the fused magnesium oxide powder can distort the results of the analysis of the impurity content by an order of magnitude. The powders are certified according to TU 1527-082-05802299-2010. The value of the base (MgO) turned out to be underestimated compared to TU by 13.23% (wt.). Integration of the detected elements, conversion to oxides and approaching 100% (wt) led to an increase in impurities by 4-5 times. To overcome this problem, two methods of correction of composition measurement results are usually used. It is a set of relevant standards or software that considers the interaction of atoms in the test (based on the data of simple substances). In the absence of these corrective possibilities, a third method is proposed for the first time. It consists in the procedure for reliable measurement of the base, mass fraction of MgO by chemical methods of arbitration analysis. Melting of parallel samples powders in salt melts → leaching → purification of impurities → filtering → dilution in a measuring vessel → titration of aliquots with fixanal EDTA in an ammonia buffer with the indicator eriochrome black T unequivocally confirmed the content of the MgO base (96.2; 96.7%), and therefore the impurities: Al₂O₃, SiO₂, P₂O₅, CaO, Fe₂O₃, Ni₂O₃ according to TU. The obtained results made it possible to correct the results of X-rays fluorescence analysis measurements and to confirm the compliance of the composition of batches of molten MgO powder with the relevant regulatory documents.

Keywords
magnesia, instrumental methods, X-ray fluorescence

Acknowledgments
Not provided

References
[1] R. Albert and W. Horwitz, А heuristic derivation of the Horwitz curve, Anal. Chem,1997. V. 69. P. 789–790