The scale of waste formation from coal-fired generation is significant and tends to grow steadily in the context of the global use of coal for power production. This paper covers the problems and current opportunities for recycling coal fly ash waste from coal generation from the position of a stakeholder approach, namely, identification of the main participants and determination of the effects for economic agents in coal fly ash recycling projects. Based on the method of economic modeling and the empirical assessment of project efficiency, this paper presents alternative patterns of stakeholder interaction in the process of implementing coal fly ash recycling projects, estimates the effects of using coal fly ash, and identifies conflicting interests between stakeholders. It is shown that the reason behind the low interest of the Russian private sector in the processing of coal fly ash is the lack of stimulating market mechanisms for manufacturers and consumers of ash products, the high risks of implementing recycling projects based on clean coal technologies, and low environmental payments for commercial companies.

Перечень материалов, подлежащих сварке взрывом, весьма обширен и составляет несколько сотен сочетаний различных сплавов и металлов, а многообразие схем сварки взрывом насчитывает более тысячи вариантов. Практически во всех технических решениях процесс предусматривает последовательное создание физического контакта свариваемых материалов и их соединение за счет пластической деформации контактирующих поверхностей. Прочность такого соединения зависит от режима протекания процесса сварки. При правильном подборе параметров режима возможно получить качественное соединение требуемой прочности, однако экспериментальный подбор таких вариантов является весьма трудоемким и затратным процессом.Компьютерное моделирование и применение математических моделей для решения динамических задач механики взрыва упрощает поиск оптимальных параметров и позволяет в кратчайшие сроки прогнозировать ожидаемый результат. В статье рассмотрены вопросы моделирования сварки металлов взрывом, расчеты, связанные с параметрами процесса образования сварного шва посредством программного пакета Ansys Autodyn. Представлена модель для анализа деформационного процесса сварки взрывом пластины и ее соединения с матрицей. Определены основные параметры сварки взрывом (скорость, давление, время). Адекватность получаемых значений оценивалась в системах алюминий -медь, медь -сталь. Выполнен сравнительный анализ результатов моделирования и натурных экспериментов.На основе численных расчетов обоснован вывод о пригодности полученной модели для предварительного анализа основных параметров сварки на подготовительном этапе.Ключевые слова: математическое моделирование; динамические процессы; деформационные процессы; сварка металлов взрывом; режим протекания процесса сварки

Abstract. Technological features of ore mining in the open pit development for processing of complex structured ore deposit of steeply falling occurrence have been considered. The technological schemes of ore bodies mining under different conditions of occurrence, consistency and capacity have been considered and offered in the paper. These technologies permit to reduce losses and dilution, but to increase the completeness and quality of mined ore. A method of subsequent selective excavation of ore bodies has been proposed. The method is based on the complex use of buffer-blasting technology for the muck mass and the principle of trim blasting at ore-rock junctions. IntroductionThe development of rare earth and precious metals deposits is carried out by the complex technological process, since, such deposits often consist of heterogeneous mineralization structure. Typical features of such deposits are: irrigularity of thickness of the seam bearing and dipping with the heavily disturbed bedding, the presence of seam swelly and wedging-out, debris interbeds; unstability of the quality of the mineral and uneven distribution of the metal.Taking into account the dynamics of the world rare-earth and precious metals markets, as well as the cost of materials and labor, the manufacturer seeks to optimize the parameters for the extraction of high-grade ores. Manufacturers have introduced the methods for 100% extraction of ore reserves from the mineral wealth and increased the production and processing of non-commercial reserves as well.The level of ore loss and dilution in quarries of rare-earth and precious metals is determined by the quality of rock mass preparation for the excavation (the degree of mixing and the displacement of ores and rocks during the explosion) and the purity of the ore mass digging.The issues of losses and dilution standardization should include the following main tasks: operational testing and constructions of high-quality planning, blasting and excavation operations, the choice of effective blasting schemes, using ignition schemes of charges taking into account the the ore bodies location. It is necessary to save the historical, geological ore structure and to reduce displacement of ore bodies and rocks at a blasting point to a minimum as well as to achive excavation and shipment of shot rocks [1].The effective and rational method of the blasting with further selective excavation of ore in complex geological conditions is one of the main methods of reducing costs for technological cycles of excavation and ore processing [2,3].

The conditions of declining gold grade in the ore, increasing depth of excavation, and de-creasing unallocated stock of deposits make it necessary to develop efficient solutions for the mine-to-mill process, which have to be adapted to each specific mining plant and will optimizes production costs. Current research focuses on a case study that demonstrates how indicators of mining losses and dilution influence the variation of costs chain in the production cycle. The article examines the topical issue of determining the effects at the mine-to-mill stages due to changes in losses and dilution. The author’s approach to the formation of a mine-to-mill cost chain is proposed by integrating several cost estimation methods into the general cost estimation methodology. The estimation methodology is a compilation of factor analysis and cost engineering methods that take into account the change in costs due to the variation of losses and dilution. It was proven that with variations in losses and dilution, cost savings arise due to changes in the volume of work on ore averaging, ore transportation, and beneficiation. For the case of the Kuranakh ore field, there are no effects at the mining stage. The use of internal reserves by means of managing ore quality parameters allows reducing the costs per ton of processed rock mass along the entire production chain.

Quality of blast preparation for rock beneficiation influences both on integrity of mineral stock in particular and in economical performances of enterprise operations in general. While rock processing for obtaining of crushed stone the yield of screenings is high, its amounts depend on rock strength properties. Investigation into the influence of drilling and blasting parameters on strength properties of blasted rocks is an urgent research and practical task for mining companies producing building stones. This article discusses results of full-scale experiment aimed at determination of strength of blasted rocks in shotpile with accounting for fracture zones as a function of rock massif saturation with energy of explosive substance.