Valleriite, (Cu,Fe)S2n(Mg,Al,Fe)(OH)2, and related layered minerals are of interest due to their unusual two-dimensional structure, formation mechanisms, physical and chemical properties, and potential involvement into mineral processing and materials science applications. Here, we have studied Kingash Cu-Ni ore samples containing 10-25% of valleriite in association with serpentines (lizardite and chrysotile) and magnetite using scanning electron microscopy and electron microprobe analysis, Mössbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis and zeta potential measurement. The data are compared with those for Al-doped valleriite synthesized via a hydrothermal route. It was found that the Kingash valleriite contains excessive iron relative to CuFeS2 stoichiometry, which mainly occurs, leaving aside magnetite, as Fe3+-OH species in hydroxide layers of valleriite and minor Fe centers in serpentines. Thermal dihydroxylation of hydroxide layers of valleriites occurs near 500 oC in inert atmosphere; in air, sulfide sheets oxidize with an exothermal peak at 447 oC, and sulfur oxides don’t volatilize but react with hydroxide groups of valleriite rather than serpentines. Zeta potential measurements of coarse ore particles using the flow potential technique suggested that the surface of valleriite is negatively charged in a wide pH range while the positive values at low pHs for fine particles are inflicted by serpentine. The findings demonstrate close resemblance of the natural and synthetic Al-doped valleriites, and the key role of valleriite, despite its moderate content, for the interfacial characteristics of the valleriite-bearing ores.

Due to transport incidents and accidents involving dangerous goods, which cause significant damage to the infrastructure and environment, there is a need to study ways of preventing losses from these accidents and minimizing their costs. The purpose of the paper is to develop a method for determining the acceptability of transport operations involving dangerous goods under normal conditions. The methods used in the study include analysis and synthesis, risk management and Delphi methods. The key outcome of the study is a developed method founded on an integrated generalized criterion for acceptability of the main transport operations involving dangerous goods. This criterion is based on risk assessment. It has been established that the safety of transportation is determined by the maximum level of dynamic loads, impact velocity, energy absorption efficiency, braking mode of railway cars, and degree of risk.

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Introduction. Fires in high-rise buildings and structures constitute a grave danger both to the people inside, valuables, and the building structure. More often than not, fires develop on the external surface of construction facilities that are in operation or inside those facilities that are under construction, and they give rise to the problem of using standard fire extinguishing solutions and require the employment of mobile machinery by fast response units of the fire-fighting service who apply fire extinguishing agents from the outside of a building. The purpose of this article is to substantiate the in expediency of, or, on the contrary, the need to make the proposed amendments to Federal Law No. 123-FZ of July 22, 2008 “Technical Regulation of Fire Safety Requirements”.The scope of the problem. The analysis of the effectiveness of various methods of application of fire extinguishing agents used to extinguish outdoor fires in high-rise buildings has shown the insufficiently high efficiency of ground-mounted machinery, which preconditions the need to make an enquiry into the possibility of using aircraft to extinguish high-rise buildings and structures. Given the need to ensure effective fire extinguishing, meet safety and economic feasibility requirements, an autonomous unmanned aerial vehicle (AURA) was selected as the delivery vehicle. Systems using various fire extinguishing agents and methods of their application were used for fire extinguishing purposes, including a pulsed water application system, capsules containing the fire extinguishing composition, high-pressure water mist and compressed air foam. Their applicability at the height of 300 meters has determined their choice.Research results. The testing task was to confirm the possibility of application of fire extinguishing agents to the fire seat in the course of the flight of an unmanned aerial vehicle, to identify the effectiveness of fire extinguishing agents and to assess the stability of extinguishing agents applied to the fire seat. To ensure safety, testing was carried out at the height not exceeding 10 m, and the results confirmed the possibility of using the above substances to extinguish fires.Conclusions. The research has confirmed the possibility of using unmanned aerial vehicles and various methods of fire extinguishing by means of the horizontal application of extinguishing agents inside high-rise buildings and structures, if extinguishing agents are applied from outside of a construction facility.

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