Severe gas disasters in deep mining areas are increasing, and traditional protective coal seam mining is facing significant challenges. This paper proposes an innovative technology using soft rock as the protective seam in the absence of an appropriate coal seam. Based on the geological engineering conditions of the new horizontal first mining area of Luling Coal Mine in Huaibei, China, the impacts

The present work aimed to study the effect of slurry conditioning on flocculant-aided filtration of coal tailings by the analysis of filtration kinetics and filter cake structure. Laboratory filtration tests of the coal tailings showed that both the shear rate and agitation time have significant effects on filtration rate and cake moisture. Moderate agitation at the shear rate of 92 s−1 was favorable

Underground gassy longwall mining goafs may suffer potential gas explosions during the mining process because of the irregularity of gas emissions in the goaf and poor ventilation of the working face, which are risks difficult to control. In this work, the 3235 working face of the Xutuan Colliery in Suzhou City, China, was researched as a case study. The effects of air quantity and gas emission on

The distribution characteristics and evolution law of rock mass fissures induced by mining are a key scientific issue in the study of deep rock mechanics. In this study, a series of uniaxial compression experiments was conducted on rock-like specimens containing double V-shaped prefabricated fissures at dip angles of α = β = 45°, α = 45°<β = 60°, α = β = 60°, and α = 60°<β = 75° with a rock mechanics

Accumulation of float coal dust (FCD) in underground mines is an explosion hazard that affects all underground coal mine workers. While this hazard is addressed by the application of rock dust, inadequate rock dusting practices can leave miners exposed to an explosion risk. Researchers at the National Institute for Occupational Safety and Health (NIOSH) have focused on developing a water curtain that

Nitrogen is widely used to prevent the spontaneous combustion of coal in underground coal mines. A spontaneous combustion-prone coal seam was studied to investigate the restraining effect of nitrogen on coal oxidation in different oxidation stages, based on non-isothermal thermogravimetry-differential scanning calorimetry (TG-DSC) and electron paramagnetic resonance (EPR) experiments. We found that

A physical model for the footwall slope of Nanfen open-pit mine, China was established using a self-developed deep geological engineering disaster model test system. A thermosensitive similar material, paraffin, was selected to simulate a weak structural plane in the slope to reproduce the landslide process. From an experimental perspective, the variation trend of shear strength parameters of weak

Coal seam gas content is frequently measured in quantity during underground coal mining operation and coalbed methane (CBM) exploration as a significant basic parameter. Due to the calculation error of lost gas and residual gas in the direct method, the efficiency and accuracy of the current methods are not inadequate to the large area multi-point measurement of coal seam gas content. This paper firstly

Digitalisation in mining refers to the use of computerised or digital devices or systems and digitised data that are to reduce costs, improve business productivity, and transform mining practices. However, it remains increasingly difficult for mining companies to decide which digital technologies are most relevant to their needs and individual mines. This paper provides an overview of digital technologies

Monitoring and assessment of underground climatic conditions are necessary to identify potential hazards and initiate remedial measures in advance that otherwise would lead to disastrous conditions. This paper discusses the concept of real-time monitoring and assessment of climatic conditions in a typical underground mine using sensors and GIS tools by utilizing a laboratory scale model. Typical ventilation

Directive (EU) 2017/164 establishes a fourth list of indicative occupational exposure limit values (IOELVs) to protect workers from risks of exposure to hazardous chemicals. It states that in underground mining and tunnelling, Member States may benefit from a transitional period regarding IOELVs for nitrogen monoxide, nitrogen dioxide, and carbon monoxide, during which the existing established IOELVs

It is pretty challenging and difficult to quantitatively evaluate the intensity of dynamic disasters in deep mining engineering. Based on the uniaxial loading-unloading experiments for five types of rocks, this paper investigated the energy evolution characteristics, and identified the damage and crack propagation thresholds. Also, the fragment size distributions of the rocks after failure were analyzed

Gas-solid fluidized bed separation is a highly efficient and clean technique for coal separation, and can effectively remove ash and sulfur contained gangue minerals from coal. However, the fine coal plugging distributor often leads to uneven fluidization and affects the separation effect. In this paper, different plugging ways were designed to study their effects on the fluidization characteristics

Underground mines in Arctic and Subarctic regions require the preheating of mine intake air during winter. The cold fresh air of those remote areas can be as severe as −40 °C and commonly needs to be heated to around +3 °C. This extensive amount of heating is usually provided by employing large-size air heaters, fueled by diesel, propane, natural gas, or heavy oil, leading to high energy costs and

With depletion of shallow deposits, the number of underground mines expected to reach more than 3 km depth during their lifetime is growing. Although surface cooling plants are mostly effective in mine air-conditioning, usually secondary cooling units are needed below 2 km depth. This need emerges due to the elevated thermal impacts caused by auto-compression of mine air as well as heat emissions from

An increase in methane, spontaneous fire and bumping hazards in Polish hard coal mines, observed in the last two decades, led to the need to elaborate the tools allowing proper selection of a range of preventive measures to fight them at the stage of designing coal extraction. Designing the production of a coal seams in the conditions of associated methane and spontaneous fires hazards in Polish hard

In this study, uniaxial compressive strength (UCS), unit weight (UW), Brazilian tensile strength (BTS), Schmidt hardness (SHH), Shore hardness (SSH), point load index (Is50) and P-wave velocity (Vp) properties were determined. To predict the UCS, simple regression (SRA), multiple regression (MRA), artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS) and genetic expression

In early 2018, the Boliden Garpenberg operation implemented an optimized control strategy as an addition to the existing ventilation on demand system. The purpose of the strategy is to further minimize energy use for main and booster fans, whilst also fulfilling airflow setpoints without violating constraints such as min/max differential pressure over fans and interaction of air between areas in mines

A complete thermodynamic model is described for temperature and heat flow distribution simulation for ventilation networks in underground mines. The method is called the Computational Energy Dynamics (CED) model of the heat, mass, and energy transport. The Thermal and Humidity (TH) transport elements of the full model are described for advection, convection, and accumulation, encompassing heat capacity

The fracture behaviour and crack propagation features of coal under coupled static-dynamic loading conditions are important when evaluating the dynamic failure of coal. In this study, coupled static-dynamic loading tests are conducted on Brazilian disc (BD) coal specimens using a modified split Hopkinson pressure bar (SHPB). The effects of the static axial pre-stress and loading rate on the dynamic

The Atkinson equation along with its friction factor is commonly used to estimate pressure requirement in mine ventilation. However, friction factor correlation of flow through broken rock, typically found in blasted stope, gob, rock pit or block caving rock deposits, etc., is currently unavailable. Also, it is impractical to conduct direct measurements of flow resistance in an inaccessible broken

Excessive exposure to heat can lead to injuries, illness, and death among mineworkers. The actual cost of heat-related injuries and illnesses is unknown because of underreporting and lack of symptom recognition. Multi-factorial, evidence-based, and field-ready guidelines for identifying–and predicting–physiological markers of heat strain are currently unavailable. The predicted heat strain (PHS) model

Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted a study in an isolated zone of an underground mine to characterize aerosols generated by: (1) a diesel-powered personnel carrier vehicle operated over a simulated light-duty cycle and (2) the simulated repair of existing equipment using manual metal arc welding (MMAW). Both the diesel-powered vehicle and MMAW

In 2012, the International Agency for Research on Cancer (IARC) classified diesel particulate matter (DPM) as a carcinogen to human. With the increased usage of diesel equipment in underground mines, miners have a high risk of over-exposure to DPM, which has drawn many concerns from the public. This study used computational fluid dynamics (CFD) to analyse the DPM dispersion and concentration distribution

The ultimately exposed roof area (UERA) of goaf is crucial to the safety and economics of underground mining. The prediction models do not consider the mechanical weakness of rock mass and ignore the influence of the joint damage factor, causing a large predicted exposure area with a high roof falling risk. This work adopted joint damage factor to derive a new UERA prediction model. The relationships

One area of concern in longwall coal mines is the active gob directly behind the longwall face, where high concentrations of methane are likely to accumulate and active roof caving occurs. Using computational fluid dynamics (CFD) to simulate gas flows in and through the gob, most researchers have represented the entire gob as a porous medium governed by Darcy’s law. However, Darcy-type porous flow

A comprehensive understanding of the failure behavior and mechanism of coal is a prerequisite for dealing with dynamic problems in mining space. In this study, the failure behavior and mechanism of coal under uniaxial dynamic compressive loads were experimentally and numerically investigated. The experiments were conducted using a split Hopkinson pressure bar (SHPB) system. The results indicated that

This paper investigated the stress evolution, displacement field, local deformation and its overall distribution, and failure characteristics of the anchorage structure of surrounding rock with different rockbolt spacing through the model experiments. The influences of the pre-tightening force and spacing of rockbolt on the support strength of the anchorage structure of surrounding rock were analyzed

The two-dimensional transient response of an imperfect bonded circular lined pipeline lying in an elastic infinite medium is investigated. Imperfect boundary conditions between the surrounding elastic rock and the tunnel are modelled with a two-linear-spring design. The novelty of the manuscript consists in studying at the same time transient regimes and imperfect bonded interfaces for simulating the

Resource modeling plays a crucial role in raw material quality management for cement manufacturing. Research has shown that geological uncertainty in resource modeling is inevitable and results in risk to future extraction planning and operations of the cement plant. This study aims to assess the geological uncertainty and associated risk in modeling a cement raw material deposit in southern Vietnam

Extreme ground behaviour in high-stress rock masses such as rockburst prone and squeezing ground conditions are encountered in a range of underground projects both in civil and mining applications. The occurrence of such ground behaviour types are difficult to predict and special design and construction measures must be taken to control them. Determining the most appropriate support system in such

The size distribution of the broken top coal blocks is an important factor, affecting the recovery ratio and the efficiency of drawing top coal in longwall top coal caving (LTCC) mining panel. The standard deviation of top coal block size (δt) is one of the main parameters to reflect the size distribution of top coal. To find the effect of δt on the caving mechanism, this study simulates experiments

The mineralogy and petrography of natural graphite in Saba Boru of Ethiopia indicate that there exists flake graphite with a slightly oval structured fine size according to our study on thin and polished sections. Herein, for estimating the carbon content in graphite, the ASTM-C561, the test method for ash in a graphite sample, was used. For characterizing graphite, x-ray diffraction, x-ray fluorescence

Strategic maintenance plays a key role in ensuring high availability and utilization of the haul trucks, and as equipment began to grow more complex towards the end of the 20th century, there was a need for a proactive maintenance strategy, which led to the development of condition-based maintenance. Real-time condition monitoring (RTCM) is the ability to perform condition monitoring in real-time and

Coal is a common porous sedimentary rock whose microstructure and mechanical behavior are often affected by high temperature. In order to deeply investigate the effect of high temperature on the structure and mechanical properties of coal, six groups of coal samples with different heating temperatures were prepared. Various testing methods, including ultrasonic test, scanning electron microscopy, nuclear

Slope failures are an inevitable aspect of economic pit slope designs in the mining industry. Large open pit guidelines and industry standards accept up to 30% of benches in open pits to collapse provided that they are controlled and that no personnel are at risk. Rigorous ground control measures including real time monitoring systems at TARP (trigger-action-response-plan) protocols are widely utilized

Estimation of horizontal stress magnitudes from borehole breakouts has been an attractive topic in the petroleum and mining industries, although there are critical research gaps that remain unfilled. In this paper, numerical simulation is conducted on Gosford sandstone to investigate the borehole breakout and its associated borehole size effect, including temperature influence. The discrete element

Blasting is the live wire of mining and its operations, with air overpressure (AOp) recognised as an end product of blasting. AOp is known to be one of the most important environmental hazards of mining. Further research in this area of mining is required to help improve on safety of the working environment. Review of previous studies has shown that many empirical and artificial intelligence (AI) methods

The environmental risks associated with casing deformation in unconventional (shale) gas wells positioned in abutment pillars of longwall mines is a concern to many in the mining and gas well industry. With the recent interest in shale exploration and the proximity to longwall mining in Southwestern Pennsylvania, the risk to mine workers could be catastrophic as fractures in surrounding strata create

Mining tailing ponds are large infrastructure objects whose life cycle spans over several decades. They are indispensable for certain types of mines where technological process produces and rejects mud. They also have potential to generate risks for human life, property and environment. For that reason, it is essential to adequately manage them throughout all the stages of their life cycle. The phase

Rockburst hazard in mining industry all over the world is one of the most severe hazards. It is becoming increasingly common because of the ever-growing depths of mining operations accompanied by the increasing strength of rocks. One of the most difficult issues is to predict this hazard before the mining operations, whether geophysical investigations have been conducted or not. Polish experience in

Poor road conditions in underground mine tunnels can lead to decreased production efficiency and increased wear on production vehicles. A prototype system for road condition monitoring is presented in this paper to counteract this. The system consists of three components i.e. localization, road monitoring, and scheduling. The localization of vehicles is performed using a Rao-Blackwellized extended

Underground coal mining frequently uses longwalls. The occurrence of a potentially explosive mixture of methane and air is one of the most serious hazards. A large number of papers have applied numerical modeling of methane propagation in research aimed at this problem. To date, none of the CFD simulations has considered the movement of the shearer in the analyses. This paper proposes an adaptation

Mine disasters occur predominantly due to methane or coal dust explosion or a combination of both. Among the top ten worst coal mine disasters in India, nine are due to coal dust explosion. The current paper describes a general overview of the parameters causing dispersion leading to coal dust explosion, and computational fluid dynamics (CFD) simulation study to observe the effects of particle size

Underground coal mining is inherently hazardous, with uncontrolled ground failure regarded as one of only several critical risks for multiple fatality events. Development, implementation and management of overarching systems and procedures for maintaining strata control is an important step to mitigating the impact of ground failure hazards at a mine site operational level. This paper summarised the

Diesel engine exhaust (DEE) and crystalline silica exposures occur simultaneously in the mining industry, and occupational sampling campaigns can be time- and cost-consuming. The authors evaluated a dual-port system for simultaneous sampling of DEE and crystalline silica in laboratory and field conditions. Laboratory tests evaluated the operation of pumps during 8 h sampling and the intensity of the

Using self-researched gas drainage borehole stability dynamic monitoring device, three-dimensional deformation characteristics of borehole under steady vertical load were researched experimentally and systematically. This research indicated that under the action of steady loading, the mechanical deformation path of the simulated gas drainage borehole is gradually complicated, and the decay of the borehole

Similar to coal, rock and gas ejections, rock mass tremors and rock bursts are among the most serious natural hazards accompanying the underground extraction of coal. Gas-dynamic phenomena caused by rock mass tremors and rock bursts observed as transient states of air parameters in mining headings, are usually generated as a result of a change in the geometry of headings and the release of considerable

The characterization of the physical and chemical properties of coal on a standard provides an understanding of its characteristics towards spontaneous combustion. The trend of linear relationships between coal recording standards (% air-dried (ad), % dry (db) and % dry ash free (daf) basis) of 30 selected coal samples from the Witbank coalfields and spontaneous combustion liability indices were evaluated

The convergence confinement methods are solutions employed to estimate convergence in circular tunnels. They are mostly based on constitutive equations governed by the Mohr-Coulomb and Hoek-Brown yield criteria. However, the solutions based on these criteria neglect the intermediate principal stress confining effect on the ground reaction estimation. Therefore, in this paper, a Drucker-Prager yield

Rocks encountered in foundations of heavy structures are invariably intersected by discontinuities (joints). In the past, several studies have been performed by researchers to incorporate the effect of fully persistent joints in the assessment of the load-carrying capacity of rocks. However, in the field, the joints are non-persistent, and an assumption of full persistency will underestimate the capacity

It is not uncommon that backfill material used in underground mining being exposed to repetitive dynamic stresses induced by blasting operations or rockburst events. Understanding the strength and fracture evolution of backfilled stopes is critical to maintain the long-term stope stability and ensure safe mining activities. This paper aims to study the damage evolution of the backfill material and

Understanding the mechanisms of the breakage of ore particles is important to predict the particle size distribution in size reduction operations. This paper aims to show the presence of common breakage modes in impact breakage and ball milling of the cement clinker and chromite samples. For that purpose, narrow size fractions of the two samples were broken in a drop-weight tester or ball mill by changing

Dust generated in mining and tunneling activities is hazardous to health of persons and safety of operations. These projects employ pick-milling machines to extract minerals and rock by mechanical breakage. The machines are equipped with flooded-bed scrubbers that encase dust particles within fine water films as particles encounter a flooded wire-mesh screen. A major disadvantage is that the screen

The main aspects that require attention in tunnel design in terms of safety and economy are the precise estimation of probable ground conditions and ground behavior during construction. The variation in rock mass behavior due to tunnel excavation sequence plays an important role during the construction stage. The purpose of this research is to numerically evaluate the effect of excavation sequence

The volume change and shear strength behaviour of tailings slurry with the changes in gravimetric moisture content is important to effectively utilise the storage volume and analysis of dam failure potential. Consolidation testing of tailings from a slurry-like to soil-like state is a critical task, and conventional consolidation apparatus does not have the capability of doing such testing, as the

Low grade dumped limestone sample having high silica of 8.1%, 36.8% CaO, and 3% Al2O3 has been studied with the aim to reduce the silica level to below 3% for its utilization in iron making. Beneficiation study of the sample was initiated with desliming of the feed sample of −100 µm to remove the siliceous ultrafine particles and to improve the feed quality. Flotation study was carried out by column

A new blasting approach of combined blastholes with different diameters is proposed to solve the problems of oversize boulders and rock toes in open-pit mine. A non-ideal detonation model and a statistical damage constitutive model are implemented in dynamic finite element analysis to investigate the formation mechanism of oversize boulders and toes. The damage distribution and evolution process of

The delivery of the inert gas through a vertical borehole using inert gas generator or IGG is investigated. Potential limitations and/or transient effects are highlighted. During the analysis, the borehole diameter, borehole length, type of borehole and partial condensation prior to entering the borehole were varied. A choked flow will occur for a contraction exit or borehole of 0.3 m in diameter if

The South African gold mining sector remains a significant contributor to the country’s economy. Facing several challenges that hinder the realisation of South Africa’s full mineral potential, the sector’s sustainability and profitability can be enhanced through implementing operational improvement measures. Mobile cooling units (MCUs) were identified as a potential focus area for operational improvement