The article describes semi-commercial testing of different technologies and facilities which ensure the required level of mining efficiency and quality of diamond-bearing ore. The use of the column charge explosives with radial clearance and air-split emulsion explosives allows stress state control in rock mass and reduces zones of high risk of crystal damage. The chain charge explosives appear to be a clever engineering idea for difficult mining conditions. The authors review the modern methods of drilling-and-blasting at mining sites of ALROSA.

The authors propose and analyze the method of soft rock reinforcement by injection of bicomponent organomineral resin with compressed-air blowing of reagents deeper in rocks. The bench tester structure, the polymeric formula, the composition and resin properties, as well as the treatment procedure are presented. The tests are described. The scope of the discussion encompasses the results of the permeation tests, strength tests and the analysis of structure of voids in sand samples after their stabilization using the proposed approach and the standard single-component resin injection. The advantages of the successive injection include the chemical treatment coverage, specific consumption of agents and the increased strength.

In this study, combustion properties such as thermogravimetric analysis and differential thermogravimetric analysis, combustion profile, ignition temperature and peak temperature were analyzed for 3 lignite samples obtained from different regions of Konya in Turkey. In the kinetic analysis, activation energies were calculated separately for four different reaction sequences using the Coats–Redfern method. As a result, when the calculated activation energies, thermal and kinetic properties of the coal samples are evaluated together, it is seen that Beysehir coal is more prone to combustion than other coals.

The spotlight is on the stress patterns in oil and gas reservoirs and in enclosing rock mass containing displaced fractures (disjunctive cleavages). The mathematical modeling finds out that with the decreasing reservoir pressure in rock mass subject to elastic deformation, the shearing stress raisers arise on the surfaces of displaced fractures and can make an initially impermeable fracture to become fluid-conductive. Creeping widens the fractures, which also contributes to hydrodynamic connection between a pay zone and the upper- and low-lying permeable strata. This process of formation of the permeable channels in rock mass can be an explanation for the mechanism of oil and gas reservoir infeed with fluid flows from the lower-lying fluid-bearing strata.

The leaching and agitation tests of gold-bearing tailings from Hassai Mine in Sudan are carried out to find the appropriate particle size that will ensure the maximum recovery. The column tests revealed that it is easy to apply and recover about 65.52% of Au content from the Au-tailing heaps at Ariab mining company by heap leach process. The obtained recovery indicates that the economic commercial viability of the process to be applied for extraction of Au in the huge tailing heaps at Ariab mines.

The author describes the specifics of the multi-scale mathematical modeling of geomedia as a case-study of a two-scale model. The first scale modeling assumes the linearly elastic medium, and the second scale model includes the plastic strains and internal friction. It is shown that in the first approximation, when the micro-scale stress gradients are assumed to be constant, the model acquires elastoplasticity with regard to local bends of structural elements of the geomedium. The solution of the problem on plane S-waves reveals that the waves possess dispersion and their velocity decreases with increasing plastic strains.

The authors discuss the influence exerted by the structural features of placers and by the distribution of useful components in them on the efficiency of the resource-saving mining. Considering clustering occurrence of gold ore seams, a geometrization error may reach 100% in some areas of operation. The errors of reserve appraisal are defined, and the applicable approaches to mineral exploration, mining and processing control are discussed. In terms of some placers in Yakutia, it is shown that the main causes of errors in gold reserve appraisal include inaccurate determination of the placer morphology and structure, the width first of all, as well as the gold content.

The authors focus on feasibility of reducing deformation of surrounding rock mass around underground structures by means of advanced reinforcement of tunnel faces in claystone. The reinforcement efficiency is estimated in 3D calculations. The factors to influence deformation in rock mass ahead of a tunnel faces include: rock bolt length, rock bolting system stiffness and the bolt pattern. An additional factor of concern is the mechanical characteristics of claystone. The implemented research shows the highest influence is exerted on deformation in rock mass by the bolt pattern and the rock bolting system stiffness. The efficient design of advanced rock bolting is determined.

Tecflote non-ionic organic agents are investigated as potential flotation collectors for copper–nickel sulfide ores. Adsorbability of four Tecflote agents having different-structure alkyl radicals and different numbers of functional groups is analyzed. The efficiency of the agents toward copper- and nickel-bearing minerals is estimated in non-frothing flotation of ore samples treated with chalcopyrite and pentlandite–pyrrhotine. The behavior specificity of Tecflote agents as compared with sulfhydryl collectors is illustrated. Tecflote agents are more active relative to nickel-bearing minerals. The flotation tests prove that inclusion of Tecflote collectors as additives to standard flotation regime enhances efficiency of the process. Partial replacement of xanthate favors higher recovery of copper and nickel in flotation froth at lower recovery of nickel in flotation tailings.

The authors substantiate applicability of type-design practice of geotechnical facilities by their complexity with a view to determining structure and contents of deformation monitoring. It is suggested to exercise the type-design practice using particular characteristics of geological, hydrogeological and geotechnical conditions of mineral mining. Based on the existing regulatory documents and considering the modern scale of open pit mining and the current dimensions of open pits, the system of particular characteristics is shaped for the assessment of open pit mining conditions. The multi-criterion analysis of influence exerted by the particular characteristics on the resultant complexity estimate of an open pit is presented. The deformation monitoring procedure for open pits depending on their mining complexity is proposed. The procedure is tested at Tsentralny open pit mine at the Khibiny apatite–nepheline deposit on the Rasvumchorr Plateau.