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By T. Krichler

"Current mine control stations are either single-position systems with high engineering effort or all-in-a-box solutions with low integration possibilities of third-party devices. Above all, both approaches are cost-intensive and not feasible for small companies. This paper shall be an inspiration of how to enhance the productivity and monitoring of an existing mining system in a modular way by introducing a proven technique of the ongoing digital revolution: A Wi-Fi network based on the communication protocol OPC UA. The starter kit consists of a single-board computer, a WLAN access point and any electronic sensor. INTRODUCTION The majority of the European mining industry is run by small and medium deposits (Europe Geology, 2017). This is due to the fact that most ore mines in Europe are widely distributed within the continent, are generally small and additionally they are often steeply inclined. Such ore bodies are normally mined with underground mining methods and must be excavated with high selectivity because of their small thickness. That is why the economy of scales, higher efficiency through bigger machines, cannot be used in most deposits in Europe except for lignite mines. It is important to find an alternative possibility to improve the efficiency of European mines for making them competitive internationally. For cost optimization and profit maximization it is necessary to use the trends of industry 4.0 and to broadcast these into the mining industry to reach a technological advantage. The goals of the EU within the Horizon 2020 funded project are to shorten the actualisation of the mine and block model to hours, improve the communication with Through the Earth (TTE) via very- or ultra-low frequency for long-time monitoring of the abandoned workings, and develop a cost-effective mine control station for optimization of mining processes in Small and Medium Enterprises (SMEs) as well. This paper deals specifically with the new approach for data acquisition, transmission and visualisation of a mine. SCADA AND ERP IN MINING There are already many Supervisory Control and Data Acquisition (SCADA) and Enterprise Resource Planning (ERP) programs on the market, but these are normally not developed for the mining industry. At the moment this leads to three options. • To hire a system integrator, who shall build a complete control station for one mine that requires a high amount of knowledge in programming and cannot be maintained by the mining company itself. • To buy different types of out-of-the-box systems, whereby every system can include some of the used technology. In this case a huge amount of project engineers and operators – at least one per system and shift- is required. • To buy every machine and program from one company including the service contracts."

Jan 1, 2018

By Kate Willa Brown Requist, Eric Lutz, Moe Momayez

As air quality sensor networks become increasingly popular in underground coal mines, it is important to generate paradigms for the application of the collected data. To date, air quality sensing has been primarily used as an early warning system for hazardous air conditions. Using data collected from a network of sensors in a US underground coal mine, we have created multiple visualization methods to show the interactions of carbon monoxide evolution with ventilation airflow. These visualization methods can allow for further analysis of the source of contaminant, as well as better data resolution across the area of concern within the mine. By utilizing univariate spatial interpolations, we present methods for identifying the movement of carbon monoxide at one-minute intervals. The resulting visualizations display the evolution of carbon monoxide concentration across a sizeable study area over a period of 14 minutes.

Jun 25, 2023

By Vince Saporito

Miners work in dangerous terrain, around the clock, with heavy equipment. Is there room for improvement in safety and standardization in the mining industry? Recent history would suggest there is a need for action. At a 2011 Spring Thaw conference in Denver CO, one speaker commented, ?We are having a number of incidents with workers getting ?pulled? into rollers or ?trapped? at transfer points when trying to manually clean (it) while the conveyor is still in motion.? It?s a troubling thought. These actions are specifically prohibited under U.S. Mine Safety and Health Administration (MSHA) regulation 57.14202. Another official from MSHA earlier this year indicated with today?s technology and policies presently in place, ?we should not be repeating the same incidents and violations year after year as we currently do.? But we are doing exactly that.

Jan 1, 2012

By Levent Ozdemir

An extensive study involving laboratory testing and computer modeling has been performed to assess the technical and economic feasibility of utilizing the recently developed minidisc cutters on roadheaders for hard rock mining. The results show that heavy duty roadheaders fitted with minidiscs can excavate hard rock formations at acceptable production rates and cutter costs. This paper presents and discusses the results of this study together with the ongoing developmental efforts of this technology, which include laboratory testing of a roadheader cutting drum with minidiscs and full scale field testing of a machine in hard rock

Jan 1, 1995

The accurate estimation of ore reserves along with capital and operating costs are two key components to the successful outcome of any feasibility study. In recent years, there have been many project failures caused by improper estimation of ore reserves. The accurate estimation of ore reserves for any deposit relies heavily on understanding its geology and underlying assumptions unique to the estimation techniques being used. The assumptions unique to commonly used traditional and geostatistical reserve estimation technique will be reviewed. The shortcomings of the estimation techniques and their possible impact on a given project's economic outcome will be discussed. The latest developments in geostatistics in overcoming existing reserve estimation problems will be presented.

Jan 1, 1994

By A. Kalogeropoulos, T. Michalakopoulos

The DEM has been used in several studies to numerically simulate the response of rocks to the cutting action with drag tools. In this research, the aim is to realistically simulate the rock material and the cutting process by controlling the grain interlocking of the numerical assembly and streamlining the calibration process while focusing on the cutting force and the failure mechanism.

Apr 1, 2023

By Judson H. Whitman

To evaluate intelligently and to market a source of rare earth raw material, it is necessary that the producer understand the requirements of the processor and the manner in which these requirements effect the value and salability of his product. This paper will be an attempt to aid in such an understanding. The majority of rare earth processors are primarily chemical companies, not mining or metallurgical companies, as the complexities of the processing procedures are' much more chemical in nature than metallurgical. The rare earths and the rare earth industry are normally divided into two groups - the ?light? or cerium group and the ?heavy? or yttrium group. They are so named because cerium and yttrium are the most common elements in 'heir respective groups and are so divided on the basis of mineralogical and chemical characteristics. The dividing line of the two groups is not rigidly fixed but usually is considered as being between samarium (atomic number 62) and europium (atomic number 63). Although the two groups are quite similar, processing procedures differ significantly, hence most processors tend to specialize in one group or the other. There is, however, a growing tendency toward participation in both groups.

Jan 1, 1960

By David Mast, Amanda Foote, Mina Shinouda

The Michigan DOT’s I‑75 Modernization Project, Segment 3, is a 30-year, $1.2 Billion design-build-finance-maintain project in Southeast Michigan. The scope includes building a nearly 4-mile long, 14.5-foot ID stormwater storage tunnel. The tunnel and pump station are being built concurrent with new roads and bridges, requiring multiple levels of design and construction coordination. Underground risks include the poten‑ tial for encountering granular soils, groundwater, and explosive gases. The new tunnel will be mined by a new open-face TBM and lined with a one-pass steel-fiber-reinforced precast concrete segmental lining. Shaft construction began in early 2020 and tunnel mining in July 2020.

Jun 13, 2021

By Richard A. Levins

The imposition of non-market regulations, such as the proposed SO2 standards for coal combustion, will typically lead to less efficient (thus more costly) production in a free enterprise system. For the coal industry these increased costs will occur in several ways, among which are mining less accessible low sulfur reserves and transporting low sulfur coal to distant markets. There are, of course, social benefits of reducing the S02 emissions from the use of high sulfur coal. The social benefits include decreased health risks, reduced damages to property, and certain unmeasurable benefits associated with the aesthetic appeal of clean air. Proponents of Federal S02 standards argue that the benefits gained from reduced emissions will exceed the costs borne by the coal industry and society in general in meeting the regulations. The purpose of this paper is to investigate the degree to which costs of meeting future energy demands from coal will change under different sulfur standards. No attempt is made to estimate the benefits of imposing regulations. Specifically, the impact of SO2 standards on the private costs of meeting regional coal demands, the competitive positions of the nation's major coal producing regions, the degree to which strip mining as opposed to underground mining will be feasible, the amount of coal being processed, and the amount of coal transported over major rail routes will be analyzed.

Jan 1, 1976

By Yi Luo, FENGLIANG WU

Mine gob has long been a safety concern in the coal industry due to the air flowing through the gob area. Therefore, knowledge of the airflow distribution and locations of hazard zones in longwall gob is important to prevent and control these hazards. Due to the inaccessibility of mine gob, many numerical studies have been performed to simulate gob air leakage using computational fluid dynamics (CFD) programs, but most of the studies isolated the gob from the mine ventilation network (MVN) with only predefined pressure boundary conditions. The MVN is, in fact, not static in a dynamic longwall mining process, and it consequently changes the boundary conditions and the gob flow field (GFF). Therefore, the MVN should be incorporated in the CFD model to prescribe the transient boundaries. However, it is very challenging to couple the 1D MVN and the 2D/3D GFF to make the mine ventilation simulation realistic. This research uses a proposed novel finite tube method (FTM) to couple the MVN and GFF. In the FTM, the GFF is discretized into a finite number of flow tubes, each of which is formed by two adjacent streamlines. These tubes connect the MVN into a new coupling network. Based on the FTM, a model for gas migration in gob is established for delineating the hazard zones of explosive methane concentration and spontaneous combustion.

By Mustafa Kumral, Yuksel Asli Sari

Underground mining operations are sensitive to price fluctuations because they usually perform with a narrow profit margin compared to open-pit mining. Furthermore, the economic evaluations regarding operation are based on estimated or simulated grades rather than actual values. These bring a high degree of uncertainty to the viability of an operation. Hence, mine planning that accounts for uncertainty is crucial for underground mining operations. As an underground mining technique, sublevel stoping has geotechnical, curing time, seismicity, cost minimization, and production requirements. A new mixedinteger linear program is proposed that considers the uncertainty associated with net present value using chance-constrained programming. The net present value (NPV) maximization objective is transformed into a multi-objective maximization problem where one objective is to maximize the mean NPV, and the other objective is to maximize the negative standard deviation multiplied by a scalar called risk or reliability level. The balance between the two objectives was maintained by this scalar and was selected based on the reliability level of the project. A case study was conducted with varying reliability levels, and sequences were generated. It was shown that the expected net present value increased at higher reliability levels, and the overall value of the objective function decreased as the reliability level increased. In other words, the variance component penalized the value of the objective function. Moreover, it was observed from the case study that at lower reliability levels, stope grade order bears similarity to the extraction order.

Aug 4, 2023

By D. W. Mitchell

Never increase, reduce, or remove ventilation without unquestionable, compelling reasons. This rule applies every day as well as when fighting fire, attempting to find survivors, or recovering the mine. Right now in some mine a miner is adjusting a regulator in one place to get more air into another. The chances are the desired result will be achieved. Has the miner done a good thing? NO! Solving the immediate problem reinforces the belief he or she can do it again. That "again" might be, to give but one of many examples, the explosion in Greenwich No. 1 Mine. Robbing the proverbial Peter can be the prelude to disaster in a mine. Reducing the airflow is a common practice when fighting a mine fire. In fact, some people have been taught to do that at MSHA's academy. People who believe that to be proper must be people who never experienced a fire. To fight most fires you have to scramble to get enough air. An explosion demands totally different "thinking". If people are soon to go into the mine, DON'T adjust the ventilation. If teams are in the mine, each affected area must be explored or sealed before making any ventilation change.

Jan 1, 1993

By R. Bishop, J. Baggett, J. Monsalve, N. Ripepi, A. Soni

Technology plays an ever-increasing role in improving the safety and efficiency of mining operations. Laser scanning and photogrammetry are two useful methods for capturing 3D digital representations of real world objects. While both technologies have been applied to the mining industry in numerous ways, the practical applications in an operating underground limestone mine has been tested for this paper, including for visualization and site characterization. Each technology is capable of creating highly detailed geospatial point clouds, but are all point clouds created equal? This paper presents a comparison of a laser scan and photogrammetry of a limestone pillar and addresses the strengths and limitations of each method for creating digital models of operating underground limestone mines. INTRODUCTION The United States crushed stone business is a ~$14 billion per year industry representing 1,430 companies which operate 3,782 mining operations across the 50 states. In 2017 alone, 1.33 billion tons of crushed stone was produced with 76% used predominately for road construction and repairs, but also for the production of cement, lime, chemical and agricultural uses. Over 70% of domestic crushed stone producers source their material from limestone and dolomite deposits, with currently only 82 mines (2%) operating underground (USGS, 2018). Underground mining requires a different technical skillset, and poses great challenges for production that must be both safe and economical. Therefore, there are many risks that an operation must mitigate in order to produce underground limestone. Some of the challenges in underground limestone mining involve geological hazards that are unique to the rest of the industry. The geologic features such as faults and weaknesses can be difficult to assess in a production environment (NIOSH, 1998). The consequences of failure due to improperly designed underground mining ground support systems, such as from a roof failure, are not only life threatening for the miners themselves, but can easily shut down an entire mining operation.

Jan 1, 2019

By Dan Swidrak, Bill Zietlow

Halfway through a 17,770-ft long stormwater tunnel, an 11-ft diameter TBM encountered a karst void below the Mississippi River in Missouri, resulting in significant inflow. It was decided that the TBM could not safely advance without external intervention. Low-mobility grout was pumped from the surface. A rescue shaft was constructed and a conventional tunnel with spiling support was mined back to the machine. The TBM was removed and a 14-ft diameter TBM equipped with probing drills was relaunched. Probing from the new TBM encountered one additional karst feature but the machine advanced after grouting and successfully completed the tunnel.

Jun 23, 2024

By G. D. Hood

The U.S. Bureau of Mines investigated rapid froth flotation through more efficient bubble-particle collisions that improved the overall flotation kinetics. An in-line static mixer efficiently mixed the bubbles, water, and ore, selectively attaching these bubbles to the hydrophobic mineral's surface. As the mixture entered the flotation chamber, the hydrophobic mineral was already attached to the bubbles and was quickly floated away from the remaining ore pulp. The rapid flotation system was evaluated for beneficiation with a western porphyry copper ore containing 0.67 pct copper, and a phosphate-bearing amine flotation tailings sample containing 9.5 pct P2O5 in a quartz matrix. Over 88 pct of the copper was recovered from the ore in a rougher concentrate containing 5.9 pct copper at a rate 7 times faster than conventional flotation. Sixty percent of the quartz in the phosphate-bearing sample was floated at a rate 4 times faster than conventional flotation. The unfloated product retained 80 pct of the phosphate in a l6.9-pct P2O5 concentrate.

Jan 1, 1993

By Aliakbar Golshani, Behnam Eslami

"Surface settlement adjacent to sensitive structures is a challenging issue in the tunnel engineering. In this study, 3D simulation of TBM excavation has been performed with the FLAC3D code and then the results compared with real monitoring data. Sensitivity analysis was carried out for all parameters affecting the surface settlement, such as the tail void grouting pressure (Pt), the face pressure (Pf), the tunnel diameter (D), overburden (q), shield thickness (t) and the length of the shield (L). The results show that the face pressure, tail void grouting and tunnel diameter have a considerable effect on the maximum ground displacement.In this paper, the monitoring data from Mashhad Metro was used to verify the numerical simulation. Data monitoring for about 47 sections between A2 and D2 stations was selected and a multiple regression analysis was performed. Based on this analysis, an empirical relationship was obtained for the coefficient of regression relationship which confirmed the sensitivity analysis.INTRODUCTIONThe surface settlement due to tunnel excavation is a complex issue, since the surface displacement is a function of several parameters that they are related to the excavation method, soil characteristics and TBM elements. Prediction of deformation is a very important issue, especially in urban areas, since these displacements may be affected the superficial structures. In recent studies, one of the most popular empirical relationships that is used to predict the surface displacement has gussian curve that it was suggested by Peck [1, 2]. An analytical relationship was proposed by Chow that its base assume was isotropic of soil, that surface settlement can be estimated based on the tunnel geometry and the shear modulus(G) [3]. Besides these methods numerical approaches such as the Finite Element Method (FEM) and the Finite Difference Method (FDM) have been used over the last twenty years, since numerical modeling has a high capability to simulation a complex soil conditions and irregular geometry [4]. In this study, all aspects of the EPB-TBM on Mashad Metro Line 2 were modeled and the most important influences on surface displacement in urban areas were determined [1, 3]."

Jan 1, 2016

By A. H. Farazi, C. Quamruzzaman

The freezing and subsequent solidifying of unstable, weak (sands, silts and clays) and/or wet soil to form a desired-shape frozen barrier around a construction area are possibly the main features of the freezing method for shaft sinking. The barrier, along with strengthening the soil, provides a dry environment to ensure sustainable subsurface construction work before placing a permanent lining. The freezing method requires the installation of freezing pipes in boreholes around the construction area and the circulation of chilled salt water through these pipes and has long been a proven technique for dry shaft sinking through unstable and water-bearing seam around the world. As removing heat from the ground is the main feature of the method, an efficient thermal design of the freezing process is mandatory to ensure success of the shaft sinking operation. This applies to both the sustainability and economy of the intended structure. The design presented in this paper is aimed at figuring out the heat-removing ability and operating time of the refrigerative equipment using some simple formulae. The authors adopted a theoretical approach to determine the quantity of heat to be removed from the ground. The amount of energy for the equipment was found to be greater than that for freezing, which proved the validity of the design. The active freezing period was calculated to be 121 days. The authors followed the structural design of the freezing process they proposed in their previous work (Farazi and Quamruzzaman, 2013). Though the first coal seam in the coalfield was encountered at a depth of approximately 352 m in the subsurface, the target depth for cooling and freezing was decided to be 162 m. The formation demands extra care to nullify its risk of the temporary structure collapsing and water rushing in (Farazi et al., 2012). Discussion on the determination of refrigerative equipment parameters was excluded from the scope of this work.

Jan 1, 2014

By Ronney Rodrigues Silva, Renata Mendonca, Gabi Knesel, Cathrine Monyake

Locus Mining is working side-by-side with a prestigious iron ore company to evaluate the addition of Locus ESG-friendly green flotation reagents with the primary goal of improving recovery and grade. In this paper, we will focus on the cationic reverse flotation application. The most “established industry” reagents for cationic reverse flotation are amine as the collector, starch as the depressant, and in some cases frothers are also used (among them MIBC, pine oil, others). Here, we evaluate the synergies of different classes of eco-friendly biosurfactants and industry-standard reagents during the cationic reverse flotation method. Exploratory research was done first with an analog sample under different pHs, eight different biosurfactants with starch and no-starch, and a customized DOE was used to perform 145 microflotation tests. The results show Separation Efficiency from 20% (baseline) to 50% (biosurfactant), and Selectivity from 3.27 (baseline) to 5.67 (biosurfactant). Optimized result conditions were then applied to the iron ore samples received from our client to perform flotation tests on a Denver Lab cell. Similar results were obtained by improving Separation Efficiency and Selectivity, which corroborate with the previous work.

Feb 1, 2025

By Gary Brierley, Lok Home

"The majority of tunnels for civil engineering applications are now being constructed using some form of mechanical excavation. Beginning in the 1960s with rock tunnel boring machines (TBM), the tunneling industry has introduced both earth pressure balance (EPB) and slurry pressure balance (SPB) soil machines; mixed soil and rock machines and a variety of different mechanical devices for the construction of small diameter tunnels. Over time, these machines have become more powerful and more adaptable to a wider variety of ground conditions; so much so that tunnels are now being constructed in ground conditions and in the vicinity of third-party impacts that would have been considered beyond the state of the art just 10 years ago. Figure 1 is an example of a mixed ground crossover TBM used successfully at Mexico City’s Túnel Emisor Poniente II.All of the above is highly advantageous for the tunneling industry, but it has also placed a much higher level of risk on the performance characteristics of the tunneling machines, on the contractors operating those TBMs and on the manufacturers of those machines. Most of the risks for a tunneling project are associated with creating the space inside of which the finished facility will be constructed. In order to create that space, the tunnel contractor must make many decisions about the best way to excavate the ground, the best way to control the ground at the face of excavation and the preferred method for supporting the ground around the tunnel in a manner that is safe for the workers and stable with respect to all of the overlying and adjacent existing structures. If it is proposed to use some form of TBM in order to build the tunnel, then the TBM becomes central to all three of these activities and becomes an integral part of managing the risks associated with these activities."

Jan 9, 2018

By Sunny Schoone, Maximilian Getz, Felix Leaman, ELISABETH CLAUSEN

Hydraulic transport is commonly used in mining for moving particles or ore concentrates in pipes over long distances with a water stream. Control and monitoring of this process require sensor technology that can obtain relevant characteristics of the two-phase flow. This work investigates the acoustic emission (AE) technology for monitoring a hydraulic system with different sand concentrations, showing the strong relationship between friction behavior in the pipe and the measured AE signals.

Apr 1, 2023