THE IMPORTANCE OF INORGANIC SALT ADDITION IN DISORDERING THE STRUCTURE OF MECHANICALLY TREATED CHROMITE. Razvorotneva L.I., Grigorieva T.N. , Moroz T.N. United Insnitute of Geology, Geophysic and Mineraloqy, Siberian Branch RAS, 630090 Novosibirsk, Russia

Mechanical explosion on solids causes their structure to be changed essentially. The changes are characterized by arising new inner interfaces as well as dislocations and various modes of point defects. The small concentrations of surfactants implanted in the layers near surface are favourable for enhancement of structure changes when disordering under mechanical explosion.

In the present work the introduction of the inorganic salts in the layers near surface of chromite as one of the most stable minerals to mechanical and chemical explosions was carried out.

The estimation of deformability degree of covalent bonds in inorganic addition - chromite system when forming the defects was defined by method of infrared spectroscopy. The appearance of additional vibrational frequences indicating the formation of new complexes surface - addition was observed in the infrared spectra. The bands of the stretching internal modes of carbonate ions at 1375 and 1530 cm^-1 in the spectrum of the mechanically treated chromite with Na₂CO₃ additions were recorded. This values differ from the free CO₃-ion mode value and 1460 cm^-1 band of Na₂CO₃ inorganic salt.

The change of structure perfection of chromite was investigated by method of X-ray diffraction with using Fourier - analysis. When dissolving the mineral particles layer by layer the relationship between the sizes of coherent dispersion blocks as well as microdistortions and depth of layer near surface has been established. Size of coherent dispertion blocks depend on type of inorganic salt addition. When Na₂CO₃ was added to chromite the last was distroyed till 500 Å blocks. Distruction was enchanced five-fold by using NH₄Cl as addition.