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The analysis of rock flow patterns under the cross-effect of contiguous faces uses the 3D discrete element method to reproduce ore drawing processes in underground mining at the Khibiny apatite-nepheline deposit. The study of ore drawing modes revealed the mechanisms of loss formation, as well as the rational designs of structural components of a mining systems and ore draw planograms. The numerical modeling results were verified during in-situ experimental blasting and sublevel stoping in different geological and geotechnical conditions in mines of the Kola Division of APATIT. A conception of sublevel stoping modeling is developed, and the guidelines are proposed for rating ore losses and dilution in underground apatite-nepheline ore mining. The efficiency of the reagent is proved.

The authors identified the cause of loss of diamonds with nonstandard natural luminescence intensity in X-ray fluorescent separation. The technology of adjusting spectral and kinetic characteristics of diamonds is developed as treatment of diamond-bearing kimberlite material by luminophore-bearing reagents including mixture of FL-530-type luminophores and anthracene. For reaching improved stability of luminophore-bearing compositions and for the better attachment of luminophores on diamond surface, it is proposed to enhance their oil receptivity by treating with a hydrophobization agent (potassium butyl xanthate). It is suggested to ensure maximal selectivity of X-ray fluorescent separation through prevention of adhesion of luminophore-bearing composition to kimberlite grains by adding dispergators at concentrations of 1-1.5 g/l. It is shown that hydrophobization of luminophore FL-530 by potassium butyl xanthate and the use of dispergators ensure selective attachment of luminophore at the surface of diamonds with nonstandard natural luminescence, as well as their selective extraction to concentrate. The overall reduction in the loss of diamonds in X-ray fluorescent separation is proved

Composition of collectors is one of the promising avenues in stimulation of flotation efficiency. When using a mix of reagents, their synergetic effect shows up not only at the mineral-liquid interface but at the gas-liquid interface as well. This study aims at connecting the synergetic effect of a cationic / anionic combination collector in reduction of surface tension with synergism of the surfactants in flotation. The tests were carried out to determine surface activity of physisorption in case of combination of these reagents. The results are comparted with the flotation activity and interaction parameter of the components of the combination. The findings can be a framework for the design approach to selecting combinations of collectors for flotation.

It is found that synergism of combination of anionic and nonionic surfactants in reduction of surface tension is connected with their synergetic effect in flotation. These effects have the same nature. The proposed hypothesis of synergism in flotation is based on the mechanism of physisorption of a collector in particle-bubble attachment. The conformity of mole concentrations of surfactants and maximal extraction of useful component to concentrate is experimentally proved. The causes of possible lack of the synergetic effect generated by cationic and anionic collectors in flotation when this effect is observed in reduction of surface tension are discussed. It is found to be necessary to take into account the interaction energy of a collector, mineral and an ambient. The analysis of change in wettability of minerals due to reagents can involve an approach using the Lifshitz theory of Van der Waals force and the acid-base interaction of contact objects. The findings can be used to develop procedures for selecting collectors and efficient reagent modes for mineral flotation.

The authors investigate depression of talc in its monomineral flotation with polymeric anion active reagents: carboxy methyl starch and carboxy methyl cellulose (CMS and CMC, respectively), sulfonates, as well as compounds with polyvalent cations of metals. Sodium polystyrene sulfonate with molecular mass of 10⁶ kg/kmol is more effective in talc depression than sulfonates of smaller molecular mass, but gives way to CMS and CMC. Cations of Mg and Al at concentration of 2.5 mg/l increase efficiency of talc depression with sodium polystyrene sulfonate by 4%. The further rise in concentration of cations of metals weakens depression of talc. Addition of sodium polystyrene sulfonate up to concentration of 250 mg/l changes electrokinetic potential of talc from - 20 to - 32 mV. As compared with CMS and CMC, polymeric sulfonates have lesser adsorption affinity to talc. The authors propose two alternative mechanisms of interaction between polymeric sulfonates and basal surface of talc: without polyvalent cations of metals and with preliminary addition of these cations.

Test flotation of pyrite used potassium butyl xanthate and sodium butyl dithiophosphate as collectors. The study of the influence exerted by the nature of a sulfhydryl collector on the flotation ability of pyrite included pyrite samples -74+44 µm in size. The findings on froth flotation of pyrite with addition of one or two traditional sulfhydryl collectors which display similar collecting action in treatment of pyrite at pH 8 are described. From the analysis of the kinetic curves of pyrite flotation, a new approach to the assessment of flotation activity of thiol collectors is proposed.

Preliminary ultrasound treatment of reagents meant for the flotation of slimes is studied. The study of the influence exerted by the ultrasound treatment applied to water solutions of nonionic collectors for flotation desliming of sylvinite ore focused on the change in characteristics of the generated foams: foam volume and height, foam ratio, moisture content, stability and breakdown rate. It is found that foamability of the solutions, foam ratio and “dryness” increase with the increasing sound power, whereas foam stability drops. The possibility of enhancing foamability and reducing stability of three-phase foams is assessed.

Electric disintegration of spodumene pegmatites is investigated. It is found that treatment with electric pulses ensures partial dissociation of monomineral spodumene, and the best extraction of spodumene crystals, either with or without concretions, takes place when initial rock is ground to a size of 1 to 4 mm. The crystals of spodumene remain unbroken, as in mechanical treatment, and represent whole pieces. The gravity separation later on allows production of spodumene concentrate for the subsequent lithium extraction.

The article presents the method of location of heavily fractured zones in rock mass. The method uses a geophysical model of electromagnetic radiation which accompanies discontinuity of rock mass. It is shown that for the location of a rock mass area with the change in the stress-strain behavior in the neighborhood of mine openings using the electromagnetic radiation method, it is required to assess the power of a source of rock failure by means of recording signals from sensors of electromagnetic radiation. An approach to building a software architecture to predict dynamic events induced by rock pressure is proposed.

The article discusses in-situ seismic tests carried out during operation in the mines Kazakhstan, Abay and Kuzembaev in the Karaganda Coal Basin for studying and predicting geological faults in coal seams. Seismic testing used the methods of reflection survey, transmitted waves, seismic location, as well as their combinations. The practical results of the in-situ seismic testing in complex geological conditions proved the efficiency of the listed methods, and enabled adjustment of the presence, position and stretch of expectable faults, revealed the absence of unpredictable faults, and detected the zones of change in hypsometry of coal seams, as well as other anomalies.