scholarly journals Blastability and Ore Grade Assessment from Drill Monitoring for Open Pit Applications

2021 ◽  
Author(s):  
Juan Navarro ◽  
Thomas Seidl ◽  
Philipp Hartlieb ◽  
José A. Sanchidrián ◽  
Pablo Segarra ◽  
...  
Keyword(s):  
Rock Mass ◽  
Rock Type ◽  
Video Recording ◽  
Monitoring Data ◽  
Open Pit ◽  
Design Parameters ◽  
Block Model ◽  
Structural Block ◽  
Strength Grade ◽  
Rock Structure

AbstractBlasting performance is influenced by mechanical and structural properties of the rock, on one side, and blast design parameters on the other. This paper describes a new methodology to assess rock mass quality from drill-monitoring data to guide blasting in open pit operations. Principal component analysis has been used to combine measurement while drilling (MWD) information from two drill rigs; corrections of the MWD parameters to minimize external influences other than the rock mass have been applied. First, a Structural factor has been developed to classify the rock condition in three classes (massive, fractured and heavily fractured). From it, a structural block model has been developed to simplify the recognition of rock classes. Video recording of the inner wall of 256 blastholes has been used to calibrate the results obtained. Secondly, a combined strength-grade factor has been obtained based on the analysis of the rock type description and strength properties from geology reports, assaying of drilling chips (ore/waste identification) and 3D unmanned aerial vehicle reconstructions of the post-blast bench face. Data from 302 blastholes, comprised of 26 blasts, have been used for this analysis. From the results, four categories have been identified: soft-waste, hard-waste, transition zone and hard-ore. The model determines zones of soft and hard waste rock (schisted sandstone and limestone, respectively), and hard ore zones (siderite rock type). Finally, the structural block model has been combined with the strength-grade factor in an overall rock factor. This factor, exclusively obtained from drill monitoring data, can provide an automatic assessment of rock structure, strength, and waste/ore identification.

scholarly journals Modelisation of fractured rock mass for open pit mining in Vietnam

2020 ◽  
Vol 61 (5) ◽  
pp. 80-96
Author(s):  
Tuan Anh Nguyen ◽  
Viet Van Pham ◽  
Nam Xuan Bui ◽  
Hoa Thu Thi Le ◽  
Hai Thi Le ◽  
...  
Keyword(s):  
Rock Mass ◽  
Fractured Rock ◽  
Construction Materials ◽  
Mining Operation ◽  
Open Pit ◽  
Open Pit Mining ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fractured Rock Mass ◽  
Mass Data

In open pit mining, besides the value of the minerals obtained, the cost of waste rock removal determines the efficiency of the mining operation. The paper introduces the rock mass data processing method and modelisation of fractured rock mass to serve the optimal calculation of technological stages in mining. This code is a discrete fracture network (DFN) code that couple geometrical block system construction based on modelisation stochastic with RESOBLOK simulations. The method of three-dimensional modeling (3D) of the fractured rock mass in the quarry is based on the rock mass data, the geometrical parameters of the open pit mine. From there, the rock mass simulation models were used in the analysis of the stability analysis of open pit benches, the optimization of the blast design parameters at overburden benches, project construction materials, and technology projects for block stone extraction. An application in some open pit mines such as quarries of Vietnam is presented.

scholarly journals Rock Mass Blastability Classification Using Fuzzy Pattern Recognition and the Combination Weight Method

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Shuangshuang Xiao ◽  
Kemin Li ◽  
Xiaohua Ding ◽  
Tong Liu
Keyword(s):  
Pattern Recognition ◽  
Rock Mass ◽  
Wave Impedance ◽  
Open Pit ◽  
Design Parameters ◽  
Rock Density ◽  
Fuzzy Pattern Recognition ◽  
Fuzzy Pattern ◽  
Weight Method ◽  
Strength Rock

Rock mass blastability classification provides a theoretical basis for rock mass blasting design, which is used to select blasting explosives, to estimate the unit explosive consumption, and to determine blasting design parameters. The primary factors that affect rock mass blastability were analyzed by selecting five indexes for rock mass blastability classification, that is, the rock Protodyakonov coefficient, rock tensile strength, rock density, rock wave impedance, and integrity coefficient of rock mass, and by identifying standards for the rock mass blastability classification and a method for testing the blasting classification indexes. The index weights were calculated using the combination weight method, which is based on game theory. A model for rock mass blastability classification was developed in combination with a fuzzy pattern recognition method. This classification method was applied to a Heidaigou open-pit coal mine, where mudstone, fine sandstone, medium sandstone, and coarse sandstone were determined to have a blastability degree of II, which corresponds to a blastability characterization of “easy,” and the unit explosive consumption of mudstone, fine sandstone, medium sandstone, and coarse sandstone was determined to be 0.44, 0.42, 0.40, and 0.36 kg/m3, respectively. These results were used to develop a loose blasting design that was effective for loose blasting.

scholarly journals Ensuring Wall Stability in the Course of Blasting at Open Pits of Kyzyl Kum Region

2020 ◽  
Vol 5 (3) ◽  
pp. 235-252
Author(s):  
Sh. Sh. Zairov ◽  
Sh. R. Urinov ◽  
R. U. Nomdorov
Keyword(s):  
Rock Mass ◽  
Strain State ◽  
Boundary Integral Equations ◽  
Video Recording ◽  
Splitting Method ◽  
Boundary Integral ◽  
Open Pit ◽  
Open Pit Mining ◽  
Stress Strain ◽  
Stress Strain State

Involvement of deep deposits in mining predetermined the trend of development of open pit mining towards increasing the depth of open pits. The main limitation imposed on drilling and blasting in the near-contour zone of an open pit is the need to protect the pit walls and engineering structures on the walls from seismic effects of huge blasts. As practice shows, the most effective and proven method of protecting pit walls is the use of blasting by presplitting method, creation of a shielding gap and a shielding layer of blasted rock mass, i.e. pre-splitting of the pit walls, preceding the huge blast. Therefore, the study of stress-strain state of the near-contour rock mass, determination of the parameters of blastholes for edge pre-splitting (preliminary shielding gap formation) in open pits is an urgent task. The analysis of the pit wall design and stress-strain state of rock mass at Kokpatas deposit exploited by Navoi Mining and Metallurgical Combine allowed to determine the model, as well as the method for calculating stress-strain state of the rock mass. When assessing stability of the pit walls, an approach known as the displacement method was used. Applying the boundary integral equations method allowed to develop an algorithm for calculating stresses in the rock mass for the conditions of Kokpatas deposit. A technique has been developed for experimental studies of blasting contour blasthole charges (blasting by pre-splitting method) using models, allowing to study fracturing on volumetric models and wave interaction by the method of high-speed video recording of the blasting process in transparent models, as well as to determine the parameters of stress waves during blasting in samples of real rocks. A method for formation of stable pit wall slopes, an excavator method for bench pre-splitting on ultimate envelope (contour) of a pit, and a method for initiating blasthole charges in the near contour zone of a pit have been developed and implemented in the industry.

Estimation of open-pit / underground mining cross-effect in complicated geomechanical conditions

2021 ◽  
pp. 58-63
Author(s):  
I. E. Semenova ◽  
◽  
I. M. Avetisyan ◽  
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
Ground Surface ◽  
Mining Operation ◽  
Open Pit ◽  
Design Parameters ◽  
Cross Effect ◽  
Stress Strain ◽  
Tectonic Stresses ◽  
Crown Pillar

The paper presents the results of prediction model studies of the stress–strain behavior in Gakman field of Yukspor deposit during hybrid open pit/underground mining under conditions of high tectonic stresses. The mountainous relief, rock mass faulting with a series of weak structures, geometry of the ore body, the actual and design parameters of stopes, and mining operation under the uncaved overlying stratum with three-sided support are taken into account. Based on the multivariate threedimensional stress–strain modeling using the finite element method, geomechanical substantiation of simultaneous open-pit and underground mining was carried out. It has been established that the geomechanical determinants in Gakman field are: – gravitational and tectonic stresses with a significant excess of the tectonic component over the gravitational component; – mountainous relief of ground surface with a significant elevation difference in the study area; – location of underground mining under the uncaved overlying stratum with three-sided support; – faulting of rock mass with a series of weak structures (Gakman fault); – formation of the open pit and crown pillar above underground mine; – significant lag of the mining front on the underlying levels of level + 320 m. The dimensions of the cross-effect zone and crown pillar when the underground operations approach the open pit mine are determined.

General concept of determining the parameters of non-mining walls of ultra-deep diamond deposits development open pits

2021 ◽  
pp. 48-53
Author(s):  
I. V. Zyryanov ◽  
A. N. Akishev ◽  
I. B. Bokiy ◽  
N. M. Sherstyuk
Keyword(s):  
Rock Mass ◽  
Structural Relaxation ◽  
Slope Angle ◽  
Field Tests ◽  
Friction Angle ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Open Pit ◽  
Open Pit Mining ◽  
Relaxation Coefficient

A specific feature of open pit mining of diamond deposits in Western Yakutia is the construction of the open pits in the zone of negative ambient temperatures, which includes thick permafrost rock mass, and which is at the same time complicated by the influence of cryogenic processes on deformation of pit wall benches. The paper presents the comparative analysis of strength characteristics in frozen and thawed rocks, stability of benches during mining, the general geomechanical approach to the determination of parameters of non-mining walls of the ultra-deep open pit diamond mines, and the parameters of nonmining walls and benches. Optimization of open pit wall configuration should primarily be based on the maximum utilization of the strength properties of frozen rocks in combination with the development of new approaches, calculation schemes and methods for assessing stability of open pit walls and benches of unconventional design, including the non-mining vertical benches. The main design characteristic that determines the parameters of open pit walls is the structural tectonic relaxation coefficient, which specifies the calculated value of cohesion in rock mass. For the diamond deposits, the values of the structural relaxation coefficient were obtained in a series of field tests and back calculations. Full-scale tests were carried out both during exploration operations in underground mines and in open pits. The accuracy of determining the values of the structural relaxation coefficient in the range of 0.085–0.11 is confirmed by the parameters of non-mining walls in an open pit mine 385–640 m deep, with overall slope angles of 38–55° and a steeper H 0.35–0.5 lower part having the slope angle of up to 70° with average strength characteristics of 7.85–11.84 MPa and the internal friction angle of 28.1–37.4°. Using the natural load-bearing capacity of rock mass to the full advantage, which the values of the structural relaxation coefficient of deposits show, allows optimization of open pit wall slope design and minimization of stripping operations.

scholarly journals Substantiation of Safe Conditions During Undermining of Hydraulic Waste Disposal

2018 ◽  
Vol 41 ◽  
pp. 01007
Author(s):  
Yuriy Kutepov ◽  
Aleksandr Mironov ◽  
Maksim Sablin ◽  
Elena Borger
Keyword(s):  
Rock Mass ◽  
Waste Disposal ◽  
Coal Mine ◽  
Water Body ◽  
Water Inflow ◽  
Open Pit ◽  
Coal Seams ◽  
Geological Conditions ◽  
Mine Workings ◽  
Mine Dump

This article considers mining and geological conditions of the site “Blagodatny” of the mine named after A.D. Ruban located underneaththe old open pit coal mine and the hydraulic-mine dump. The potentially dangerous zones in the undermined rock mass have been identified based onthe conditions of formation of water inflow into mine workings. Safe depthof coal seams mining has been calculated depending on the type of water body – the hydraulic-mine dump.

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