Mining Engineering Commons^™

Three-Dimensional Stress Evolution And Comprehensive Treatment Technology For Super-Long Working Face Across Abandoned Roadway With Large Section, Wang Yan, Xiong Zuqiang, Zhao Gaobo

Coal Geology & Exploration

In order to solved the problem of super-long working face across abandoned roadway with large section, which is easy to cause rib spalling and roof falling, based on a super-long working face in Chengzhuang mine of Jincheng, a three-dimensional model of abandoned with large section roadway was established. The roof of working face was divided into three parts: coal pillar roof, abandoned roadway roof and mining area roof. The criterion of pillar instability was deduced and the roof stress evolution process of large section abandoned roadway was analyzed by FLAC^3D numerical simulation. The results show that when the W …

Multidimensional Deformation Monitoring Using Insar Technology In Yuxian Mining Area, Du Jiantao, Yan Li, Zhao Chaoying

Coal Geology & Exploration

Yuxian County in Hebei Province is one of the largest mining areas in North China. This area has been suffering serious ground deformation due to underground mining activity, which not only threatens mining safety, but also seriously damages local ecological environment. To obtain the surface deformation map of the overall mining area and to analysis the spatiotemporal evolution features, 61 C-band descending track and ascending track Sentinel-1A/B images from July 2017 to September 2018 were processed based on Interferometric Synthetic Aperture Rader(InSAR) technique. In addition, the two-dimensional deformation time series of Xixizhuang mine were obtained by using the multi-dimensional deformation …

Ruger Approximate Formula-Based Prediction Of Fractured Reservoir, Wu Shanshan, Gao Gang, Gui Zhixian, Wang Peng, Li Chengyi

Coal Geology & Exploration

The azimuthal anisotropy of pre-stack P-wave is the most widely used method to detect fracture. This method mainly uses the long-axis and minor axis information of the ellipse fitted by the AVAZ seismic data to evaluate the fracture. When applying it in practice, it is considered that the variation of AVAZ response characteristics in the fractured reservoirs is just determined by the anisotropic parameters, and the influence of non-anisotropic parameters is not taken into account, which leads to the multi-solution of fracture evaluation. In order to improve the accuracy of this fracture evaluation technology, we started with the model analysis, …

Frequency Dispersion Mechanism Of Complex Resistivity Of Coal, Guo Yuehui, Zhang Yugui, Li Jian, Zhou Meng

Coal Geology & Exploration

In order to study the physical mechanism of frequency dispersion of complex resistivity of coal at 0-200 kHz, the amplitude-frequency and phase-frequency of complex resistivity of coal are measured under variable frequency of constant current. Using the Fourier inverse transform to convert the frequency domain data of complex resistivity of coal into time domain data; Using the Cole-Cole model, the complex resistivity dispersion data are fitted; Drawing on the electric double layer deformation hypothesis theory, the dispersion mechanism of complex resistivity of coal is studied by comparing the frequency dispersion of sandstone. The results show that in the current frequency …

Effect Of Temperature On The Performance Of Pdc Cutters With Different Shape, Zhang Suhu, Wang Chuanliu, Dai Yongbo

Coal Geology & Exploration

In order to explore the performance of PDC cutters at different temperatures to adapt to different brazing temperatures, and to reasonably select the shape to improve efficiency. Based on the several main parameters affecting the quality of polycrystalline diamond compacts (PDC), such as wear resistance, grinding time, stationarity and impact toughness, the performance of PDC sheets from different manufacturers and different shapes was tested. The performance of PDC before or after heating and at different temperatures was obtained. At the same time, the performance of flat sheets, micro-arcs sheets and arcs sheets was compared. The results show that with the …

Phytoremediation Of Heavy Metal Contaminated Wastes From Small-Scale Gold Mining Using Pityrogramma Calomelanos, Zar Che Win, Leslie Joy L. Diaz, Teresita R. Perez, Kiyohiko Nakasaki

Environmental Science Faculty Publications

In this study, viability of employing the waste treatment technique for industrial application was conducted by setting up a phytoremediation protocol for field application where heavy metal (Arsenic and Copper) contaminated adsorbents, i.e. coco peat and nanofiber membrane, used for the treatment of wastewater were also included. An arsenic hyperaccumulator, Pityrogramma calomelanos was used for the treatment of mine wastes-tailings, coco peat and nanofiber membrane. Phytoremediation procedure was established by investigating planting parameters namely ; plot height - (9 cm and 15 cm) and planting distance- (15 cm and 20 cm) for a period of five months. Translocation factor and …

Joint Simulation Of Continuous And Categorical Variables For Mineral Resource Modeling And Recoverable Reserves Calculation, Sentle Augustinus Hlajoane

Dissertations, Master's Theses and Master's Reports

Spatial variability and uncertainty of continuous variables (grade) and categorical variables (rock-types) in mineral evaluation significantly impact the economics of mining projects. The conventional approach of simulating grades using deterministic rock- types is problematic since spatial variability, and uncertainty of grades at rock-type contacts are not well captured in deposits where the grade changes gradually between rock-types. Therefore, jointly simulating these variables can improve confidence (reduce uncertainty) in a resource model. Also, resource classification and recoverable reserve calculation can significantly improve the understanding of the deposit and its economic viability. This research utilized the Plural-Gaussian geostatistical simulation to jointly simulate …

Cobalt Partitioning And Solubility In Low-Temperature Carbonate-Hydrothermal Systems, Seth Kurtis Coursey

Graduate Research Theses & Dissertations

Cobalt mineralization has been documented in low temperature Mississippi Valley-type (MVT) deposits in southeast Missouri. Lead and zinc are the most economically important metals in these deposits and are contained within galena (PbS) and sphalerite (ZnS), respectively. Cobalt is also mined in some of the deposits with cobalt-bearing ores, e.g., siegenite ((Ni,Co)3S4) and fletcherite (Cu,(Ni,Co)2S4), occurring stratigraphically below main-stage galena and sphalerite. The hydrothermal fluids responsible for cobalt mineralization are thought to be chemically distinct from the predominant MVT ore-bearing fluids and represent a distinct mineralizing event. Cobalt is likely transported as CoCl2 in hydrothermal fluids and sourced from structures …

Predicting Fracture Extension Around A Borehole Using The Numerical Displacement Discontinuity Method, Nathaniel Schaefer

Theses and Dissertations--Mining Engineering

Prediction of blast damage radius is integral in the optimization of mining safety and production. The damage radius can be related to blasting variables such as fragmentation size as well as overbreak in hard rock. Various methods have been developed to predict and assess damage radius extension for individual holes to aid in blast design. These methods range from experimental and observational techniques to theoretical applications. Some of these methods have been used with a degree of success. However, many of them lack a comprehensive combination of experimental and theoretical contributions. Since post-blast environments are not conducive to assessing whether …

Proof Of Concept For The Development Of A Ground Vibration Sensor System For Future Research In Blasting, John Meuth

Theses and Dissertations--Mining Engineering

Ground vibrations from blasting are one of the leading limitations to mining (underground and surface). There is a need for a low-cost scalable vibration monitoring system to conduct large scale ground vibration projects in the mining industry. Studies conducted on ground vibrations use any number of different sensors to obtain their data, the different sensor capabilities and methods for data processing lead to uncertainties in the research and regulations set for ground vibrations. Commercial Systems do not allow researchers to obtain raw output data, and the data processing procedures are not provided or disclosed for these systems. In order to …

The Effect Of Delay And Sequence On Blasting Fragmentation Results, Tristan Worsey

Theses and Dissertations--Mining Engineering

Blasters use the delay between charges and the firing sequence of the explosive charges to help reduce vibrations and achieve the desired fragmentation. Although delay and sequence are recognized as very important for vibrations and fragmentation, only vibration models consider timing as a variable in the prediction tool, without any known model for fragmentation prediction based on the delay sequence. Of the few fragmentation models available, very few take delay into account and do not give guidance on row delay and/or sequence selections. With the invention of electronic detonators in 1984, there are new avenues to explore with sequence and …

The Potential Of Gold Mine Development Project : A Case Study Of Chifunde District In Mozambique, Sara Mario Mabecuane

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the results of the gold exploration activities developed in the district of Chifunde, Province of Tete in Mozambique. The works showed that in the study area there are two types of deposits which are primary and secondary deposits. There was clear evidence that they have undergone high-grade metamorphism of greenschist due to the grenade occurrences in hornblende in the form of porphyroblast which indicated a high probability of gold occurrence inside amphibolic schist. The results of the SGS laboratory revealed that all samples collected in the area contained gold ranging from 1 to 2,500 ppb, whereas in …

Characterization Of Rare Earth Elements In The Illinois Basin Coals, Alireza Valian

Theses and Dissertations--Mining Engineering

The purpose of this study is to characterize the distribution and occurrence of rare earth elements (REEs) in the coal and coal-related material from the Illinois Basin. For characterizing the distribution of REEs, 17 core samples were investigated from various parts in the basin. Also, several individual samples from coal preparation plants and isolated geological occurrences were included in the study. In result, the average REE concentrations were calculated on a bed-to-bed basis, although the distribution of REEs in the coal beds was found laterally and vertically heterogeneous. A number of trends were found that describe the variations. Most importantly, …

Investigation Into Mine Pillar Design And Global Stability Using The Ground Reaction Curve Concept, Ravi Chandan Ray

Theses and Dissertations--Mining Engineering

Pillars form an important support structure in any underground mine. A bulk of the overburden load is borne by the mine pillars. Thus, the strength of pillars has been a subject of detailed research over more than 6 decades. This work has led to the development of largely empirical pillar design formulations that have reduced the risk of pillar failures and mine collapse. Current research, however, has drawn attention to the fact that some of the assumptions used in the development of conventional pillar design methodologies are not always valid. Conventional pillar design methodology assumes that the pillars carry the …

Numerical Approximation Of The Ground Reaction And Support Reaction Curves For Underground Limestone Mines, Jesus Castillo Gomez

Theses and Dissertations--Mining Engineering

Pillar stability has been a matter of study for the last 70 years. The determination of pillar strength had taken different solutions and approaches over that time. This research has led to numerous empirical formulations that have reduced the number of pillar failures worldwide. However, new numerical approaches are being studied. In the last 20 years, the Ground Reaction Curve concept has been examined as a way of understanding the convergence of the rock-mass. Although the Ground Reaction Curve was first introduced in the civil tunneling industry, several authors have introduced the Ground Reaction Curve concept as an approach for …

Investigation Of The Stability Of Liquid And Air Films By Synchronized Tri-Wavelength Reflection Interferometry Microscope, Yuesheng Gao

Dissertations, Master's Theses and Master's Reports

Liquid films are widely involved in many processes, such as froth flotation, oil extraction, foam/bubble stabilization, etc. In the meantime, air films are commonly seen in diverse fields like dust control, ink print, coating industry, and so on. Stabilities of these liquid/air films are of great importance to improve the processes. As more and more researchers are paying increasing attention to liquid/air films, tremendous efforts have been made to explore the properties of the films. On the one hand, some theoretical models have also been well developed in recent decades. State-of-the-art technologies, such as AFM, SFA, and RICM, have also …

A Novel Pixel-Based Multiple-Point Geostatistical Simulation Method For Stochastic Modeling Of Earth Resources, Adel Asadi

Dissertations, Master's Theses and Master's Reports

Uncertainty is an integral part of modeling Earth's resources and environmental processes. Geostatistical simulation technique is a well-established tool for uncertainty quantification of earth systems modeling. Multiple-point statistical (MPS) algorithms are specifically advantageous when dealing with the complexity and heterogeneity of geological data. MPS algorithms take advantage of using training images to mimic physical reality. This research presents a novel and efficient pixel-based multiple-point geostatistical simulation method for mineral resource modeling. Pixel-based simulation implies the sequential modeling of individual points on the simulation grid by borrowing spatial information from the training image and honoring conditioning data points. The developed method …

The Influence Of Spatial Variance On Rock Strength And Mechanism Of Failure, Danqing Gao

Graduate Theses, Dissertations, and Problem Reports (ETD)

The heterogeneity in the rock formation affects both rock behavior and the strength. The effect of heterogeneity is observed both at the laboratory scale and at the rockmass level. The mechanical properties of intact rock vary considerably at laboratory scale and often an average value is used for design purposes. Similarly, the values are arbitrarily scaled when used at rockmass level. In underground coal mines, the effect of variability of properties is often observed with the erratic roof failure events that occur throughout the mine. The approach often was to use the deterministic values from limited site data to estimate …

Upstream Tailings Dam - Liquefaction, Mladen Dragic

Graduate Theses, Dissertations, and Problem Reports (ETD)

The collapse of Dam I, tailings dam, at Vale S.A.’s (“Vale”) of the Córrego do Feijão Iron Ore Mine in Brazil was an accident that caused over 270 casualties and made irreparable damage to the surrounding environment. The exact reason for the failure is not known however, liquefaction was suspected to be the most influencing factor in the failure. Liquefaction failure of impoundment is increasing concern in the mining community and especially mine planners who will have to design and build the tailings dam. Different design methods are available with varied degree of challenges. Upstream construction methods, as one of …

Solution Tool To Predict Filter Cake Formation For Acid Mine Drainage (Amd) Slurries, Roberto Ecuador Martinez Ochoa

Graduate Theses, Dissertations, and Problem Reports (ETD)

Acid Mine Drainage (AMD), also known as alkaline mine drainage resulted from abandoned and active coal mining areas has been a major water pollutant in the mid-Atlantic region of the United States affecting aquatic life, recreational areas, tourism, etc. AMD results from during and post mining activities all around the US and the world containing high levels of acidic materials such as sulfate and other heavy metals.

The United States Environmental Protecting Agency (EPA) has recommended the use of different mechanisms for mitigation purposes due to considerable existing and potential damage generated by AMD. This report focuses on the usage …