Technologies of Mining Scientific Research center

Development of process regulations and technologies for exploitation of ore deposits by the underground method

Example: Process regulations on access and development of ore bodies in levels 830-1070 m & 1070-1310 m of Gaisky deposit.

Based on process regulations a feasibility study (project) was developed on mining of deep horizons of Gaisky underground mine. At simultaneous work in both levels the productivity over the underground mine will amount to 7,0 mln. tons of ore per year. Within recent years there were prepared process regulations for projects on development of deposits: Yubileyny, Podolsky, Safiansky, Novy Sibay, Novo- Uchalinsky, Ozerny and others.

Development technologies of peripheral ore reserves in edges of Sibaysky pit.

Open mining works in the pit are completed. Pit edges are set in the end position. Nevertheless, pit edges contain significant ore reserves, development of which is limited by the necessity to maintain an access ramp and impossibility to transport the freed ore from the pit bowl. There was developed a technology for developing peripheral ore reserves preserving pits edges stability. Ore extraction is carries out by so-called ore “cutbacks” (open stalls) along the pit edge. Ore drawing is performed only from underground workings. There was received around 280 thous. tons of ore.

Geographical demarcation of an open-pit field of the Yubileyny deposit on the presence of sulfur content for providing safe blasting works

These studies are held for improving safety of conducting blasting works at mining enterprises. The work consists in preliminary preparation of horizontal distribution plans of sulfur content as per data of sampling remnant ores of operational and exploration bores, that enables to predict the most explosion hazardous areas at horizons prepared for mining.

Technology for mining near-bottom and near-edge reserves of a dividing ore pillar of the Molodezhny deposit

Mining is conducted in two stages. The first stage- mining of near bottom reserves located in the ore pillar below the bottom of the pit. The second stage – mining of near-edge reserves of the ore pillar in the north-eastern edge of the pit.  Excavation work of near-bottom reserves is done by a single stall/chamber, with an outcome of the extraction space of this chamber to the pit. The second stage begins with an erection of a combined pillar from the combination of a rock fill- consolidating stowing along the ore part of the pit edge. The formation of the pillar is carried out in ascending order “in steps” by height of 5 meters.
Mining of near-edge reserves is conducted under surcharge of the combined pillar by a sub-level-chamber system of mining followed by a subsequent filling of chambers with a stowing mixture. The proposed mining technology will enable to mine around 500 thous. tons of ore from the dividing ore pillar of Molodezhny deposit safely and efficiently with min losses and dilution.

Technology for chamber mining of ore reserves with sub-level breaking and “chessboard manner of mining” for deep horizons of Gaisky deposit

A developed technology of the chamber mining of ore reserves with sublevel breaking and with “chessboard manner” of mining will enable to provide safe and productive mining (up to 7,0 mln. tons per year) of deep horizons of a deposit with minimum losses and ore dilution.

Technology for mining of Ozerny deposit by means of sublevel-chamber system of development with an ascending reserves excavation

Technology of a sublevel-chamber development system with the  ascending excavation of reserves will allow safe mining of the Ozerny deposit with a capacity of 400-500 thous. tons per year and significantly saving materials for the production of filling operations.

Assessment of a seismic impact on a peripheral massif of the Yubileiny pit after a preliminary fissure formation

With the approach of blasting sites to a limiting contour of Yubileyny pit, for ensuring the sustainability of the Southwestern edge of the pit, there was provided the application of a special technology DBO allowing minimizing residual deformations of rocks beyond the limiting contour. Instrumental seismometric observations were conducted to estimate the seismic influence at blasting operations on the South-Western edge of the Yubileyny pit.  In order to define efficiency of the preliminary fissure formation and estimation of the influence level of blasting operations on the contour massif of the South-Western edge, during measurements there were installed seismographs by Uran-Intelecon in the zone of a contour fissure absence and directly after the contour fissure.

By result of seismometric studies conducted it was found that actual speeds of seismic vibrations during blasting operations do not exceed a permissible speed 9.3 sm/s both after the zone of the preliminary fissure formation and beyond this zone. Beyond the zone of the preliminary fissure formation there was recorded a sharp decrease of the seismic influence on the massif and was confirmed the efficiency of the preliminary fissure formation: based on abovementioned studies in order to provide overall sustainability of the Yubileyny pit edges and to prevent from accumulation of residual deformations of massifs when conducting blasting operations it was recommended: in zones of semi-stable rocks and specially protected areas the contour blasting should be conducted by a method of the preliminary fissure formation.

Predicted mathematical modelling of a stressed-deformed state of the rocks massif

Major criterion for defining the optimum order of chamber reserves mining is the change of stressed-deformed state (SDS) of the massif in the process of mining operations. The application of the mathematical modelling of the massif SDS change enables to solve this target.
One of such examples can serve the performed mathematical modelling of different mining schemes of ore reserves at the north flank of the 5th ore body located in the upper layer of Uzelginsky deposit in the level of 200/140m.

Geomechanical classification of a massif stability at selecting mine workings supports

The paper reflects main decisions on decreasing a massif stability indicator (RMR),developed by a professor Z.T. Benyavski depending on the influence of external conditions, such as blasting, weathering of rocks, stress changes under the influence of the actual mining and the quality of the exposed surface. The result – defining the type and structure of the support for  preparation and cut depending on class of the rock massif by a technique developed by Mr. Barton.

Development of guidelines on supporting and maintaining permanent, development workings and breakage headings

After studying engineering-geological conditions of the deposit, an estimation of the rock massif stability is given. The estimation is conducted in two stages: preliminary estimation at the design stage of a header and final estimation at the implementation stage of the header. As per conditions of the rock massif stability a selection of the support form and structure for permanent, development and breakage headings was made. Afterwards, for each working a support pattern and strata control is prepared. All works on designing supports, support patterns preparation and performance of works on supporting underground mine workings is realized in accordance with requirements of Unified Safety Regulations.

Process regulations development of stowing complexes for mines development by underground method

  • Regulations comprise technology and equipment for feeding base materials to a technical process of mixtures preparation;
  • Technology and equipment for preparation of stowing mixtures;
  • Calculation of material flows of base materials with respect to different stowing mixtures compositions, and based on this
  • guidelines for dosing equipment;
  • Technology of feeding the ready mixture to a stowing bore hole, including device that allows to shift from a stowage of one chamber to another without breaks providing a continuous work of the complex within several days;
  • Instruments process flow diagram allowing preparing a mixture in the basis of different base components, as well as at their simultaneous use with various ratio to each other.

Paste stowing mixtures for stowing mined-out space

There were developed compositions of stowing mixtures on a basis of concentration tailings and combinations tailings+ break-stone (graded—20 mm). It was established that the strength of paste mixtures is 1,3-1,5 times as many than of cast mixtures of the similar composition. There were conducted tests of paste mixtures compositions completely excluding water loss of the mixture. Putting the stowage based on coarse material tailings in the amount of 30% & 50% of a filler weight to the composition enabled to increase the strength by 25% at average.

Technology of using concentration tailings for stowing mined-out space

Due to the limited possibility of storing concentration tailings of the plant studies are conducted to find methods of their utilization.

Utilization of concentration tailings as a part of the stowing mixture is regarded  as one of ways for partial solving the problem of disposal of industrial wastes. Developed compositions of stowing mixtures with the use of concentration tailings as a part of the filler at Uchalinsky GOK passed industrial tests at mines of the plant. Test results proved to be reasonable for using concentration tailings in the process of stowing of mined-out space. Production costs of stowing mixtures are reduced by 12%.

Development of techniques to undertake pilot testing of new technologies

Development of techniques to undertake pilot testing of new process variants of separate ore bodies enables mining companies to carry out development of complicated deposits areas with minimum ore losses. Within recent years, a number of pilot testing techniques was developed for mining deposits such as Uchalinsky, Uzelginsky, Molodezhny, Gaisky, Sibaysky and others.

Technology for building up a nonmining flank of an opencast.

An invention is related to a mining industry and can be used for open cast mining. The purpose of this invention is to reduce mine preparation and stripping works and to increase a number of adjoining safety berms to a transport cross-over. The target goal is achieved through the way of building the nonmining flank of the opencast including a construction of the transport cross-over, horizontal and inclined berms, inclined safety berms are built in places of their adjoining to the transport cross-over, but the slope of inclined safety berms is restricted in accordance with technical features of machines and mechanisms applied for cleaning berms from screes (slide rocks).

Implementation result:

  • decrease of scopes of mine preparation works due to reducing inclined berms in bulk volume when forming the nonmining flank of the opencast.   
  • decrease of scopes of stripping works due to replacement of horizontal berms by inclined ones at areas of adjoining to the transport cross-over.

Development of observation projects of pits edges deformations and earth surface displacement

Observation projects are necessary for controlling deformation processes of pits edges and earth surface at open and underground mining methods. Monitoring enables to provide timely development of activities on securing pits edges stability, to notify about emerging deformations, keep correcting slope angles depending on variable mining-and-geological situation in the process of mining operations as well as when reaching the limiting contour and setting edges to a limiting position. At underground deposits development method instrumental observations enable to follow the influence on underground workings and earth surface, as well as caution about dangerous deformations for underground and surface objects.

Observation stations are founded as a system of support and working fixed data that are located on the earth surface in the rock mass and in structural elements of building & constructions (special observation stations)

Technology for defining maximum slope angles of pits edges

The main point of the technology consists in multivariant estimation of pits edges stability considering all of factors with detalization up to a separate bench.

Application area: design stage of mining operations, pits exploitation, capability assessment of mining peripheral reserves, pits depreservation. Objects of research: in the world- Chile, Mongolia, Angola; in CIS- Blyavinsky, Sibaysky, Buribaevsky, Uchalinsky, Gaysky, Akzhalsky, Zagliksky, Tassevsky GOK and etc. Result: increase of design angles of pits at safety ensuring of the mining production involving additional volume of minerals and reducing stripping works, mining peripheral reserves, resumption of works at preserved pits.

Technology for laser scanning of industrial & civilian objects

Technology of surface laser scanning consists in measuring distances up to a big amount of points located on the subject under scanning. Measurements are carried out with a speed up to 122 000 points/sec.

The application of this technique at Sibaysky, Uchalinsky & Yubileyny pits enabled to carry out a volumetric analysis of deformation processes in pits edges.

Area of application:

  • highly detailed shooting of dangerous & inaccessible objects;
  • laser scanning of the area;
  • preservation of architectural heritage;
  • detail inspection of actual parameters of benches and pits edges;
  • tunnel shooting;
  • architectural shooting, inspection of buildings & constructions;
  • monitoring of the state of industrial and civilian objects;
  • providing mine-surveying works
  • shooting of power transmission line and linear objects.

Result – highly detail 3D computer model of millimeter accuracy.  Technology of reflectionless surveys of deforming areas of pits edges is tested under industrial conditions at Sibaysky, Uchalinsky, Yubileyny and Sultanovsky pits. Implementation of a high- performance scanner Riegl VZ-1000 enabled to create a highly detailed model of Yekaterinburg circus.

Technology for building up a nonmining flank of an opencast in clay rocks

Invention is related to a mining industry and can be used during open-cast mining of water-bearing deposits of minerals. The method includes development of a border zone by inclined layers, formation of water outlets and backfill of a created nonmining bench between adjacent horizons by an inside dump of hard rocks.

The application of the method enables to increase the stability of benches slopes and pits edges due to reduction of a weakening impact of water on clay rocks and improve operation conditions of ore mining machines & equipment. The novelty and practical value of the invention consists in increasing slopes stability of clay rocks by means of a rocky surcharge and intensification of water disposal from berms to a pit sump system. The invention was implemented at the Yubileyny pit (the Republic of Bashkortostan) and can be used at many others. Implementation result: reduction of stripping works at ensuring safety of mining operations.

Methods of reflectionless observations of deforming areas of pits edges and dumps

The main point of observations is confined to gridding and scanning of observations area (zone of deformations) with a sufficient density of observations for providing simulation adequacy. Periodicity of scanning is defined on the basis of a stage of deformation processes. By results of each series of scanning, a 3D model of an area of observation is designed. As the coordinated of the area are known, then when combining models of several series of observations we can follow the dynamics of development of soil slips.

By results of modelling the volume (m3) of deformations between initial series and subsequent observations is calculated. The application of methods of  laser scanning is regarded as one of the most efficient and safe ways of conducting instrumental observations on deforming areas of pits edges and dumps.

Surveying security ensuring of mining operations

Conduction of integrated geomechanical research including surveying instrumental observations, estimation of borders of dangerous deformaions of pits edges, a near edge massif and earth surface in a process of underground and open mining of deposits.

Performance results of works:

  • setting borders and type of dangerous deformations;
  • defining the value and speed of rocks displacements;
  • defining the critical speed of displacements, preceded by beginning of soil slips or deformations;
  • assumption of displacements development through time at increasing the pit’s depth;
  • prevention of the influence of dangerous displacement processes on mine openings and earth surface;
  • recommendations on preserving pit edges, the near edge massif, buildings and constructions in the zone of influence of open & underground operations.