Abstrato

The identification of iron in a Spanish coal using low temperature Mossbauer spectroscopy (4.2°-40K)

M.A.Ahmed, M.J.Blesa, R.Moliner

The method of using low temperature Mossbauer spectroscopy to identify the iron species in coal is illustrated for sub bituminous (AA5) and semi-anthracite (BZ) coals. The 4K spectrum of the AA5 sample exhibits besides pyrite and rozenite a magnetically split ferric component compatible with jarosite (H=485 kOe). Whilst, set of low temperature spectra of the BZ sample, taken respectively at 9K, 20K, 30K and 40K indicate besides pyrite and szomolnokite other two relaxation sextets belong to siderite and ankerite. Furthermore, analysis of iron by the method of atomic absorption spectroscopy and according to ASTM methods for coal showed the presence of organically bound iron (0.133 % Fe.) in the BZ sample. The existent of an organic iron in a coal sample is of a great importance, which will be inevitably discussed in this work.