scholarly journals Effect of Compressive Behaviours of Tail Salt Filling Materials on Roof Deformation in Potash Mine

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jiaqi Wang ◽  
Qiang Zhang ◽  
Meng Li ◽  
Hengfeng Liu ◽  
Cunli Zhu
Keyword(s):  
Lower Layer ◽  
Ore Deposits ◽  
Environmental Damage ◽  
Filling Materials ◽  
Filling System ◽  
Geological Conditions ◽  
Mechanical Behaviours ◽  
Pillar Mining ◽  
The Stability ◽  
Potash Mine

To resolve the problem of top mine instability and the consequent ecological damage caused by different grades of ore deposits in the layered mining process, layered filling-pillar-mining-displacement method (LFPMD) is proposed using a potash mine as an example. Based on the operation principles of the tail salt filling system, the mechanical behaviours of the tail salt under initial tamping and overburden loading were obtained through compaction tests in the laboratory. In addition, the mining-filling mass ratio of tail salt was derived. Based on the mining geological conditions of a potash mine in Laos and the compaction characteristics of tail salt, a mechanical model of top control by tail salt and a numerical model of top control by the pillars were established to discuss the stability of the upper-layer top mine and the lower-layer top mine. It was found that when the elastic foundation coefficient of the tail salt is greater than 550 MN·m−3, and the width of the retained pillars is 10 m, stability of the upper layer and the lower layer can be guaranteed. The results revealed that the LFPMD method can ensure stability of the overburden in the stope and reduce environmental damage while treating tail salt underground.

scholarly journals Novel Segmented Roadside Plugging-Filling Mining Method and Overlying Rock Mechanical Mechanism Analyses

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2073 ◽  
Author(s):  
Wenqiang Mu ◽  
Lianchong Li ◽  
Zhongping Guo ◽  
Zhaowen Du ◽  
Sixu Wang
Keyword(s):  
Coal Mining ◽  
Surrounding Rock ◽  
Equivalent Model ◽  
Mine Pressure ◽  
Mining Method ◽  
Operation Process ◽  
Geological Conditions ◽  
Pillar Mining ◽  
The Stability ◽  
Site Test

The no-pillar mining method is widely used in coal mining engineering because of its superiority in resolving mine pressure hazards and protecting natural resources. In view of the geological conditions of stable strata in a coal mine of the Shandong Coal Zone, a novel segmented roadside plugging-filling mining method is proposed by introducing the filling coefficient into roadside filling. The operation process is designed with a new grouting filling forming device. Based on the relationship between the theoretical deflection of a cantilever beam and geometric settlement and parallel settlement models, strength formulas applicable to the segmented roadside plugging-filling (SRPF) method at different migration stages are obtained, and the deformation formulas of a roadway toward a rock slab are solved by an elastic equivalent model. Further, the determination procedure of the filling mode under the mining method is clarified. The SRPF method was implemented on a test stope, and the test results indicated that the theoretical deformation produced by the SRPF method was small and can meet the mining requirements. Through on-site test monitoring, the deformation of surrounding rock was 0–160 mm and the filling body under the SRPF method could maintain its own strength and the stability of the surrounding rock. In addition, entire successful mining been completed in the working stope, which further proves the applicability of this method. The backfilling cost of the gob-side filling was reduced by approximately 50%, and the backfilling efficiency was improved in the mine. The description of the novel mining method may provide theoretical and practical guidance for coal mining in similar geological conditions.

scholarly journals Development of the Digital Model for the Selection of Mine Working Support in Complex Mining and Geological Conditions

2019 ◽  
Vol 134 ◽  
pp. 01009
Author(s):  
Aleksandr Kopytov ◽  
Vladimir Pershin
Keyword(s):  
Mine Working ◽  
Ore Deposits ◽  
Digital Model ◽  
Mining Institute ◽  
Russian Research Institute ◽  
Geological Conditions ◽  
Iron Ore Deposits ◽  
The Stability ◽  
High Level ◽  
Research Institute

The methodological basis for the development of a multi-factor digital model for selecting efficient and safe mine working support for given mining and geological conditions on the basis of the assessment of rock mass stability conditions depending on its fracturing and stress state when mining iron ore deposits of Gornaya Shoria is presented. The need to solve fundamentally new problems related to the application of various types of support systems is due to the changeover of mines to ore mining at great depths and classifying deposits as liable to rock-bumps. It is a very important factor, because a decrease in the stability of workings is associated with a high level of stresses in the deep levels being worked out, increased by bearing pressure, which ultimately leads to an increase in the cost of maintaining them. The developed multi-factor digital model “EvrazrudaKrep”, which is based on the results of the analysis of guidelines and instructions of the institutes such as All-Russian Research Institute of Mining Geomechanics and Survey, East Research Institute of Ore Mining, Mining Institute of Siberian Branch of Russian Academy of Science, T.F. Gorbachev Kuzbass State Technical University, as well as the mine working support experience in Russia and abroad, allows to quickly solve the problem of choosing a support and improving mining safety in complex mining and geological conditions.

scholarly journals Industrial Experiment of Goaf Filling Using the Filling Materials Based on Hemihydrate Phosphogypsum

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 324
Author(s):  
Kuanwei Rong ◽  
Wentao Lan ◽  
Hongyan Li
Keyword(s):  
Laboratory Experiments ◽  
Surrounding Rock ◽  
Ecological Environment ◽  
Engineering Practice ◽  
Industrial Experiment ◽  
Filling Materials ◽  
Filling System ◽  
The Stability ◽  
Activation Conditions ◽  
Cementing Material

The surface stockpiling of phosphogypsum not only occupies a large amount of land, but also seriously harms the surrounding ecological environment. The preparation of phosphogypsum into filling materials for mine filling can not only maintain the stability of surrounding rock, reduce surface subsidence, enhance the recovery of resources, but it can also completely solve the problem of phosphogypsum stockpiling. Under certain activation conditions, hemihydrate phosphogypsum has a strong cementing property. It is an important way to reduce the filling cost by using hemihydrate phosphogypsum instead of cement as a cementing material. Through laboratory experiments, the filling materials based on hemihydrate phosphogypsum were developed. In order to further verify its feasibility in practical filling engineering, the industrial experiment of goaf filling was carried out in a phosphorus mine. The results show that the filling system was simple, reliable, and easy to operate and manage. The strength of the filling body basically reached the expected strength target of 2.5 MPa in 3 days. The consolidation speed of the filling materials was faster, which is beneficial to the safe underground construction of the mine. The results of the industrial experiment of goaf filling indicate that the filling materials based on hemihydrate phosphogypsum are suitable for mine filling engineering practice, the work amount is small, and the filling cost is low.

scholarly journals EVALUATION OF THE STABILITY OF A TEMPORARY PILLAR WHEN MIINING ORE HORIZONS WITH BACKFILLING AND CAVING

2021 ◽  
Vol 2 (3) ◽  
pp. 123-134
Author(s):  
Sergey Yu. Vasichev ◽  
Alexander A. Neverov
Keyword(s):  
Raw Materials ◽  
Ore Deposits ◽  
Geomechanical Model ◽  
Mining System ◽  
Room And Pillar Mining ◽  
Mining Front ◽  
Pillar Mining ◽  
The Stability ◽  
Enclosing Rocks ◽  
Safe Mining

A method is proposed for mining thick and flat ore deposits at great depths in conditions of a decline in the value of extracted mineral raw materials. It is found that safe mining with solidifying backfill and caving is achieved by determining the parameters of stable spans of rooms, in place of which artificial supports and temporary ore pillars are formed. These pillars are recovered with a lag behind room-and-pillar mining by caving of ore and enclosing rocks. It is shown that, depending on the type of geomechanical model of geomedium and orientation of the initial natural stresses acting in the rock mass relative to the mining front, the field of application of the mining system is limited by the depth and parameters of excavation. Predictive areas of possible rock failure are determined applicably to rock masses with different degree of disturbance.

Sustainability and adaptability of regional development in the conditions of digitalization

2020 ◽  
Vol 19 (9) ◽  
pp. 1550-1613
Author(s):  
O.E. Akimova ◽  
S.K. Volkov ◽  
E.A. Gladkaya ◽  
I.M. Kuzlaeva
Keyword(s):  
Sustainable Development ◽  
Regional Development ◽  
Economic Behavior ◽  
Regional Inequality ◽  
Environmental Damage ◽  
Economic Potential ◽  
Human Welfare ◽  
Long Time ◽  
The Stability ◽  
Smart Technologies

Subject. The article discusses the sustainability of regional economy development, its definition, and the substance of sustainable development. Objectives. We aim at performing a comprehensive analysis of indicators of sustainability and adaptability of regional development in the context of digitalization, formulating a strategy for economic behavior that takes into account the multidimensional nature of regional inequality and is focused on boosting the economic potential of regions. Methods. The study draws on dialectic and systems approaches, general scientific methods of retrospective, situational, economic and statistical, and comparative analysis. Results. The sustainability of the region focuses on improving the human welfare over long time horizon. This happens in three areas, i.e. maximizing the efficiency of resource use; ensuring justice and democracy; minimizing resource consumption and environmental damage. The stability of the region can be assessed by using one parameter, or by combining the parameters in accordance with the type of region and expected results. Conclusions. The adaptation of a region to changing conditions depends on its type (‘adapted’, ‘adaptive’, and ‘non-adapted’). Regional inequality has two main components: difference in economic potential and social satisfaction of residents. Another component, affecting the stability and adaptability of regions, is the level of their digitalization. However, some regions have only formally embarked on the path of digitalization. Moreover, a focus on smart technologies, solutions and digitalization often leads to ignoring the goals of sustainable development. Smart technologies should be aimed at ensuring sustainability within the framework of the smart sustainable city concept.

scholarly journals Performance Evaluation of Heading-and-Winning Machines in the Conditions of Potash Mines

2021 ◽  
Vol 11 (8) ◽  
pp. 3444
Author(s):  
Sergey A. Lavrenko ◽  
Dmitriy I. Shishlyannikov
Keyword(s):  
Energy Efficiency ◽  
Experimental Studies ◽  
Efficiency Coefficient ◽  
Mechanized Method ◽  
Methodological Approaches ◽  
The Stability ◽  
Technical Solutions ◽  
Potash Mine ◽  
Complex Indicators ◽  
Potassium Magnesium

The authors focus on the process of potash ore production by a mechanized method. They show that currently there are no approved procedures for assessing the performance of heading-and-winning machines operating in the conditions of potash mines. This causes difficulties in determining the field of application of heading-and-winning machines, complicates the search for implicit technical solutions for the modernisation of existing models of mining units, prohibits real-time monitoring of the stability of stope-based technological processes and makes it difficult to assess the performance of the services concerning mining enterprises. The work represents an aggregate assessment of the performance of heading-and-winning machines for potash mines by determining complex indicators describing the technological and technical levels of organising the work in stopes. Such indicators are the coefficients of productivity and energy efficiency, respectively. Experimental studies have been carried out in the conditions of the potash mine of the Verkhnekamskoye potassium-magnesium salt deposit to assess the performance of the latest and most productive Ural-20R heading-and-winning machines manufactured in Russia. Using the above methodological approaches, this paper shows that the unsatisfactory technological performance of the studied machine is due to the low productivity of the mine district transport. The average productivity coefficient was 0.29. At the same time, high values of the energy efficiency coefficient show that the productivity of the machine is on par with design conditions.

scholarly journals Study on instability failure mode and monitoring early warning standard of surrounding rock in fully weathered argillaceous sandstone section of large section tunnel

2019 ◽  
Vol 136 ◽  
pp. 04023
Author(s):  
Ming Zhao ◽  
Ke Li ◽  
Hong Yan Guo ◽  
KaiCheng Hua
Keyword(s):  
Limit State ◽  
Stable State ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Large Section ◽  
Rock Stability ◽  
Geological Conditions ◽  
Construction Step ◽  
The Face ◽  
The Stability

Based on the special geological conditions of a tunnel in Qingyuan section of Huizhou-Zhanzhou Expressway, FLAC3d numerical simulation software is used to simulate the rheological properties and instability of surrounding rock in large-section fully weathered sandstone section, and the stability and loss of surrounding rock are analyzed. The deformation of the dome and the face at steady state is analyzed. It is found that: 1) when the surrounding rock is in a stable state, the deformation curve of the dome is smooth. When the surrounding rock of the face is unstable, the front of the face appears ahead. Deformation should be first strengthened on the surrounding rock in front of the face. 2) The arched foot is an important part of the instability of the surrounding rock. In order to prevent the expansion of the collapsed part, the arched part should be reinforced. 3) In order to obtain the limit state of surrounding rock stability, the strength of surrounding rock is reduced, and the strength reduction coefficient corresponding to the displacement sudden point is taken as the safety factor of rock stability around the hole, and the stability safety coefficients of surrounding rock of each construction step are greater than 1.2. 4) The dynamic standard values of deformation control in the whole construction stage are obtained by analyzing the deformation curves of each data monitoring point with time in the corresponding time period of each construction step.

scholarly journals Influence of Crack Geometry on Dynamic Damage of Cracked Rock: Crack Number and Filling Material

2020 ◽  
Vol 11 (1) ◽  
pp. 250
Author(s):  
Feili Wang ◽  
Shuhong Wang ◽  
Zhanguo Xiu
Keyword(s):  
Energy Absorption ◽  
Split Hopkinson Pressure Bar ◽  
Mineral Exploration ◽  
Damage Variable ◽  
Filling Material ◽  
Hopkinson Pressure Bar ◽  
Filling Materials ◽  
The Stability ◽  
Pressure Bar ◽  
Dynamic Damage

The dynamic damage of cracked rock threatens the stability of rock structures in rock engineering applications such as underground excavation, mineral exploration and rock slopes. In this study, the dynamic damage of cracked rock with different spatial geometry was investigated in an experimental method. Approximately 54 sandstone specimens with different numbers of joints and different filling materials were tested using the split Hopkinson pressure bar (SHPB) apparatus. The energy absorption in this process was analyzed, and the damage variable was obtained. The experimental results revealed that the dynamic damage of cracked rock is obviously influenced by the number of cracks; the larger the number, the higher the energy absorption and the bigger the dynamic damage variable. Moreover, it was observed from the dynamic compressive experiments that the energy absorption and the dynamic variable decreased with the strength and cohesion of the filling material, indicating that the filling material of crack has considerate influence on the dynamic damage of cracked rock.

scholarly journals On strongly nonlinear gravity waves in a vertically sheared atmosphere

2020 ◽  
Vol 6 (1) ◽  
pp. 63-74
Author(s):  
Mark Schlutow ◽  
Georg S. Voelker
Keyword(s):  
Gravity Waves ◽  
Lower Layer ◽  
Vertical Shear ◽  
Horizontal Wind ◽  
Necessary Condition ◽  
Mean Flow ◽  
Individual Layer ◽  
Strongly Nonlinear ◽  
The Mean ◽  
The Stability

Abstract We investigate strongly nonlinear stationary gravity waves which experience refraction due to a thin vertical shear layer of horizontal background wind. The velocity amplitude of the waves is of the same order of magnitude as the background flow and hence the self-induced mean flow alters the modulation properties to leading order. In this theoretical study, we show that the stability of such a refracted wave depends on the classical modulation stability criterion for each individual layer, above and below the shearing. Additionally, the stability is conditioned by novel instability criteria providing bounds on the mean-flow horizontal wind and the amplitude of the wave. A necessary condition for instability is that the mean-flow horizontal wind in the upper layer is stronger than the wind in the lower layer.

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