Profound knowledge of the structure and texture of rocks and ores as well as the behavior of the materials under external loads is essential to further improvements in size reduction processes, particularly in terms of liberation size. New analytical methods such as computer tomography (CT) were adopted to improve the understanding of material characteristics in rocks and ores relevant to mineral processing, particular the crushing and grinding and the modelling/simulation thereof. Results obtained on the texture and structure of identical samples of rather different rocks and ores (copper ore, granodiorite, kimberlite) are compared by CT with quantitative results from traditional optical microscopy obtained by quantitative microstructural analysis (QMA). While the two approaches show a good agreement of the results in many areas, the measurements with the two different methods also exhibit remarkable differences in other areas, which are discussed further. In conclusion, both methods have their specific advantages starting from sample preparation to the accuracy of information obtained concerning certain parameters of mode and fabric. While sample preparation is faster with CT and information on special distribution of metal minerals is more reliable, the information on mode, grain size and clustering seem to be more precise with QMA. Based on the results, it can be concluded that both methods are comparable in many areas, but in in the field of spatial distribution, they are merely complementary.

To assess the possibility of selective disintegration and reduction of overgrinding of hard-to-reproduce ores, optical microscopic and X-ray microtomographic studies were carried out and quantitative characteristics of morphological parameters of disseminated and rich cuprous ore samples from Norilsk-type Oktyabrsky deposit were identified. Among quantitative morphological parameters the most informative are area, perimeter, edge roughness, sphericity, elongation and average grain spacing for disseminated copper-nickel ores; area, perimeter, edge roughness and elongation for rich cuprous ores. The studied parameters are characterized by increased values and dispersion in ore zones, which is especially important for fine-grained ores, which are difficult to diagnose by optical methods. Three-dimensional modelling of the internal structure of sulphide mineralisation samples was carried out using computed X-ray microtomography, which allows observation of quantitative parameters of grains, aggregates and their distribution in the total rock volume and interrelationship with each other. The evaluation of rock pore space by computer microtomography made it possible to compare the results obtained with the strength characteristics of rocks and ores, including those on different types of crushers. The obtained quantitative characteristics of structural-textural parameters and analysis of grain size distribution of ore minerals allow us to evaluate the possibility of applying selective crushing at various stages of ore preparation

Oxide-silicate ore deposits containing approximately 10% of Ni reserves of Russia are located in the Sverdlovsk, Chelyabinsk, and Orenburg districts of the Urals. Garnierite is among the most important industrial minerals of supergene nickel deposits. We studied this mineral in metasomatites and ores of the Cheremshan, Sinar, Elov, Sakhara, and Buruktal deposits based on the chemical, thermal, and X-ray phase analysis data. It is shown for the first time that garnierites of the Ural province are composed of both exogenous and hydrothermal mineral associations. The spatial distribution of minerals suggests that the hydrothermal association is a lateral and vertical (depth) continuation of mineralization in the Uralian supergene deposits. This conclusion widens significantly the scope of prospecting for new mineralized sectors in old deposits and the possibility of discovery of new deposits.

The methods of computer X-ray microtomography were used to investigate morphometric parameters and pore space characteristics of granodiorite, copper sandstone and kimberlite samples. The results were compared with the same data of quantitative microstructural analysis. These data demonstrate a wide range of possibilities of computer X-ray microtomography in solving scientific and practical problems related to physicomechanical properties of rocks determining the output of ore minerals. X-ray microtomography allows evaluating the content of ore minerals in rocks, analyzing the granulometric composition and the spatial distribution of their grains. The method is worthwhile in obtaining not only the quantitative characteristics of the mineral phases, but also the pore space of the rock — dimensions, sphericity, pore and microcrack connectivity. The options of 3D-visualization of obtained data at a shot span time, high speed and nondestructiveness are undoubtedly the advantages of X-ray microtomography. The method provides a wide range of researches including preparation of rocks and ores for disintegration. The work was performed with the aid of the Russian Foundation of Fundamental Research (the Grant 16-05-00460 А).