The article presents an analytical review of the current state of the iron ore base of the ferrous metallurgy of Russia and the world, identifies the largest iron ore provinces and iron ore producers. The promising directions of development and improvement of the quality of the iron ore base of Russia and the features of the development of new deposits of rich iron ores are identified. Effective technologies for the development of rich iron ores deposits that ensure an increase in production volumes are proposed. The geomechanical justification of rational technological parameters that are easily adapted to changes in mining and geological conditions has been performed. Based on the results of field studies, the use of an elastic-plastic model with the Coulomb – Mohr strength criterion for modeling changes in the stress-strain state of an ore rock mass during mining operations is justified and recommendations for ensuring the stability of mine workings are developed. Effective engineering and technical solutions for the complex development and deep processing of rich iron ores with the production of fractionated sinter ore, which increases the efficiency of metallurgical processes, the production of high-grade iron oxide pigments and iron ore briquettes, which increase the competitiveness of iron ore companies and the full use of the resource potential of deposits, are presented.
When constructing buildings and structures for industrial and civil purposes, it is important to ensure safe working conditions for the tower crane operator and contractors of construction and installation works on the construction site, since these conditions largely determine the performance of the tower crane and the pace of construction in general. Accidents associated with the use of lifting equipment in construction often lead not only to injuries and death within the construction industry, but also affect passers-by who find themselves in the danger zone due to the non- compliance of the construction organization project with the requirements of existing codes of rules containing requirements for labor protection and industrial safety in construction. The article analyzes the causes of accidents in construction that result from the operation of tower cranes, as well as ways to ensure their reliable and safeoperation. The theoretical substantiation and engineering and technical solutions of safety during construction and installation works during the construction of objects due to the improvement of the design of the tower crane cabin and its equipment are offered. The results of theoretical and experimental studies of sensorimotor activity of the operator of the construction machine, which are the basis for engineering solutions developed at the level of inventions of tower cranes cabins of increased visibility and their equipment, are presented.
The article suggests the method for forecast of surface deformation during excavation operations in restraint urban conditions using the slurry trench technique based on FEM simulation. The results of numerical simulation of the construction of a semi-underground structure with slurry trench technique are given. The regularities of the change in the stress-strain state are determined depending on the trench parameters and the physical-mechanical properties of the soils. The work presents the troughs of surface subsidence during the construction of an excavation using the slurry trench technique, the diagrams of bending moments, transverse and longitudinal forces arising in the trench. Numerical experiments in Plaxis 2D and 3D were performed to estimate the discrepancy between modeling results in a plane and volumetric formulation of the problem.
An analysis of field studies for mining of deep shifts frames is presented in this article. A spatial model is developed, the results of mathematical modeling are presented, they are based on finite element method of nonlinear deformed ore body, which includes the system of wide workings on the 6-th block of –370 m horizon of the Yakovlevsky mine, which consistently pass and laid hardening mixture.
Challenges of efficient underground mining of thick flat coal seams are studied. An effective method to secure stability of site development workings in overworked layers is suggested. A conclusion is made on advisability of stress-relief workings construction in preparation of overworked layers. Parameters of slicing mining system and stress-relief workings are justified. Assessment of useful mineral loss enhancement and production cost reduction is made due to introduction of the proposed method. Possible areas are determined for application of this method.
The main ore base of the Russian aluminum industry is the deposits of the North Urals bauxite basin. The deposits are developed at depths of 900-1000 meters, and the design and opening of new horizons is planned at depths of 1500-2000 meters. The mining and geological conditions of deposit development become sharply more complicated at greater depths. To ensure the required volumes of bauxite production under such conditions, it is necessary to solve the problem of safe mining operations at deep horizons of mines.