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By Rambabu Pothina, Rajive Ganguli

The economics of a mineral-processing circuit is dependent on the numerous sensors that are critical to optimization and control systems. When a sensor goes off calibration, it results in errors that can have a severe impact on plant economics. Classical statistical approaches fail to detect when errors are “subtle,” unless they grow and become large enough to be “gross,” whereas methods based on signal processing and artificial intelligence fail in dealing with the complexity of process fluctuations. Due to the sheer volume of sensors, undetected errors are not remedied until the next calibration, which on average are a year apart across all industries [1]. This research aims to detect such subtle errors (2 percent bias) in shorter time spans of about a month — rather than wait for errors to grow — using innovative data-mining techniques and algorithms.

By Mir Ahmad Mohammadi

Land uplift due to mine flooding has become a significant challenge with extensive historical mining activities, particularly in Germany’s Ruhr district. The cessation of coal mining operations has led to a gradual rise in groundwater levels, altering geotechnical and hydrological conditions and causing surface uplift. This study develops a system dynamics (SD) model to investigate the dynamic interactions of influential variables such as groundwater levels, total stress, porosity and permeability with land uplift over time. The model integrates causal loop diagrams (CLD) and stock flow diagrams (SFD) to comprehensively understand the system’s behavior. SFD illustrated that for a 10 percent increase in groundwater level, the land uplift increased by about +6 percent, and a rise of 200 percent in total stress caused an 18 percent increase in effective stress, which decreased the land uplift by about 20 percent. This study highlights the importance of dynamic modeling in informing land-use planning and mitigating the long-term impacts of land uplift after mine closures.

Mar 1, 2025

By Ruben Piqueras, Juan Luis Magro, Jorge Vázquez, Santiago Martínez, Xavier Manjarín

The Parallel Thimble Shoal Tunnel project involves the construction of a bored tunnel under Thimble Shoal Channel in Chesapeake Bay (VA), between two artificial islands and parallel to the existing tube tunnel, built in the sixties. It will be the first transportation tunnel constructed in the Mid-Atlantic region using a Tunnel Boring Machine (TBM), a 44-foot-diameter Earth Pressure Balance (EPB) named "Chessie," manufactured by Herrenknecht, and which was assembled at the CBBT's southernmost island, with extremely limited room, live adjacent traffic, and difficult access. "Chessie" was successfully launched in February 2023 and this paper describes this complex and challenging process.

Jun 23, 2024

By J. A. Luppens

Five years ago, Phillips Coal Company decided replacing mainframe/workstation programs with a new package of PC software was clearly the best solution for computer reserve modelling. The system chosen was actually three programs distinguished by their power, cost, flexibility and integration, and ease of learning and use. Phase I involves the use of the "StratiFact" program for borehole data management and seam correlation. This phase is probably the most neglected, yet critical aspect of reserve evaluation. Phase II employs the "PC/Cores" package for modelling and volumetrics. Phase m is "PC-Cut" which provides mine planning tools including an automated cut generator.

Jan 1, 1996

By John N. Murphy

The past five years have seen communications techniques and hardware developed by the Bureau of Mines and its contractors increasingly brought into use in U.S. mines. The Bureau of Mines philosophy has been to help develop and introduce new hardware that goes as far as possible toward meeting the mining industry's needs. The Bureau of Nines programs are also designed to provide continuous fallout of new communications capabilities which are introduced to the mine operators as they occur. As more progress is made in meeting mine comnications needs, it is hoped that the mining industry will readily adopt the equipment and techniques that it finds most useful in meeting its individual needs. This paper reports on recent advances achieved in the development of improved nine communications systems.

Jan 1, 1976

By T. W. Peterson

There are two approaches to developing a minicomputer based application for an industrial grinding circuit. Usually, the control program is coded and compilation-debugged on a large-scale scientific computing system or the minicomputer itself if the machine is available. Final debugging and testing must wait for installation and checkout of the entire minicomputer system. Two immediate disadvantages of this approach are the need to obtain, install and check out the hardware before the final debugging stages of program development can begin, and interference with normal mill operation during such final testing. This work reports on an alternative to the usual procedure. Here both compilation and execution bugs are eliminated from the application program before hardware installation by testing the control program against a reasonable dynamic simulation of the entire process. Thus, software development can be completed before the target mini is installed. Such off-line development requires a reasonably accurate mathematical model for the entire process system as well as a suitable simulation package for communication between the simulated environment and the minicomputer application program. Specific data describing the design configurations and dimensions of the mills, cyclones, sumps, pump characteristics and analog controller configuration were supplied by ANAMAX for a grinding division consisting of a rod mill followed by two ball mills in parallel. This information was used to set up a plausible model structure. Steady state ANAMAX data on particle size analysis at various points in the circuit and corresponding values of flow rates, pump speeds, sump heights and slurry densities were used for model parameterization. The preferred operating control strategy - "best grind at operator-set rod mill feed rate" - was set by ANAMAX. An inferential particle size analysis technique using the cyclone cluster as an on-line particle size sensor was used in a novel control strategy_ to achieve the stated objective. Two disturbances common in the ANAMAX circuits - rod mill scoop pluggage and shut down/start up of one of the ball mills - were studied in detail. This report out- lines the steps in system development and testing and the results obtained.

Jan 1, 1974

By S. Peng, Yi Luo

Subsurface strata movements and deformations associated with underground longwall mining activities could cause certain influences to subsurface structures and water bodies. Methods have been developed for the prediction of final and dynamic subsurface movements and deformations induced by underground longwall mining operations in the eastern coal fields. Two new types of strata deformation, vertical and total strains, which could be useful in the field of subsidence research in assessing subsidence influences to the subsurface structures and water bodies, have been introduced. Using the subsurface subsidence prediction model, three types of subsidence influences to surface and subsurface hydrological systems have been identified. Attempts have been made to quantify the two types of subsidence influences that could cause water loss and could lower water levels in aquifers.

Jan 1, 2010

By BURCU NILGUN CETINER, Serdar Aktas

Antimony has been used extensively in industry and in everyday life since the 19th century, and antimony sulfides have been known since around 4,000 B.C. Antimony’s most significant applications are as a flame retardant in the manufacture of electronics and textiles, as a catalyst for plastic fabrication, and as paint pigment and fining agent in glassware, opacifier in ceramics and an alloying element in ammunition and battery manufacturing plants. It is also used in vehicle brakes and tires. Brake pads contain stibnite (Sb), the sulfide compound of antimony. In particular, stibnite is used in automobiles as a lubricant, vibration reducer and friction stability improver. Anthropogenic activities are the primary source of antimony in the atmosphere [1,2]. Annual global consumption of antimony has increased to more than 1.4 × 105 t, and China is the most significant producer [2].

By S. K. MONDAL, K. K. K. SINGH, S. Singh, R. K. TIWARY, S. K. Chaulya, G. C. MONDAL, R. S. Singh, T. B. SINGH

In this work, a comprehensive field study was carried out to measure the background air quality status and identify the air pollution sources from opencast mines around a heritage site in India. Air quality modeling was conducted to envisage dust concentration due to existing and closed mines in the region. The air quality modeling exercise predicted that particulate-matter levels of PM10 and PM2.5 might increase in the ranges of 3.2 to 23.1 and 2.1 to 8.9 μg/m3, respectively, due to mining activities when some of the closed mines will be operated in the region without controlled emission. The predicted total PM10 and PM2.5 at the selected receptor locations were in the ranges of 86.39 to 194.89 and 34.82 to 99.55 μg/m3, respectively. Adequate measures were suggested to control air pollution from mining activities, and an intelligent dry fog system was designed to suppress dust emission efficiently from mineral processing plants and opencast mines. The developed system has special features for facilitating eco-friendly mining.

By John R. Buzek

Thickeners are simply large tanks, usually circular in shape, which are designed to allow settling of solids and to operate with continuous overflow of clear water and underflow of thick pulp. The dimensions of the thickener are usually such that dewatering of very fine pulps may be accomplished while still 1 overflowing clear water. Some thickeners such as the Genter, Hardinge and Hydrotator types combine thickening with filtering2 while others such as the Dorr type are pure thickenersl,2,3. A schematic diagram of the traction type Dorr thickener is shown in Figure 1. This type is appropriate for tanks over 15 m (50 ft) in diameter. This tank employs a rotating raking mechanism which moves the settled material toward the central discharge. For this and other thickeners, it is common to have a shallow conical tank bottom in order to conform to the geometry of the raking mechanism, and it is often desirable to elevate the tank for ease of access to the product. When the tank does not rest on the ground, the forces resisted by the cone are large, and thick plates must be employed. The fabrication of these tanks requires temporary supports in order to erect the cone. A flat-bottomed tank could also be used because the settled material would soon form a hardened conical surface. However, because of the presence of large bending forces, even larger plate thicknesses are required than for the conical bottom. Significant cost savings often can be realized by the use of a scalloped-bottomed tank such as the one partially shown in Figure 2. The particular scalloped bottom discussed in this paper (and shown in the Figure) employs radial beams forming the outline of the cone-shaped bottom. These beams are supported directly by columns. Cone segments are hung between adjacent beams. The exact geometry of these segments depends upon the cone angle and radius, the number of radial beams, and their inclination. The geometry is chosen to satisfy certain clearance restraints and to utilize the material as efficiently as possible. The resulting thickness of these segments is significantly less than that of the

Jan 1, 1977

By Raul A. Deju

A theoretical and experimental study was made of the surface phenomena occurring in a silicate - sulfonate system and a silicate -amine system, Experiments were conducted varying the collector concentration to examine its effect both on the total surface sorption and the rate of sorption. The results were compared to a theoretical model based on a Langmuir-type isotherm, Finally, the flotation behavior of selected silicate minerals was predicted from the sorption results and an explanation for the flotation of silicates postulated on the basis of both the theoretical predictions and experimental data.

Jan 1, 1967

By Yi Yang, CHENGLONG XU, HAORAN LI, YALI FENG, JINRONG JU

Steel slag is an industrial byproduct of steelmaking that is mainly composed of calcium, iron, silicon and magnesium. In addition, depending on the different raw materials entering the furnace, steel slag contains a certain amount of vanadium that is the main source of vanadium production, accounting for 69 percent of the species of the total vanadium raw material [1]. From experience, the production of one ton of steel will generate 1.0 to 1.5 tons of steel slag [2]. However, the utilization efficiency of steel slag is less than 30 percent, and a large amount of steel slag is identified as waste and stacked in tailings. The random stacking of steel slag not only wastes large amounts of limited steel and land resources but also exerts pressure on the environment [3], making it imperative to research the effective utilization of steel slag and recycling of metal resources.

By J. A. Marshall

"INTRODUCTION The purpose of this paper is to investigate the potential for use of UAVs in underground mines and present a prototype design for a novel autorotating UAV platform for underground 3D data collection. The mining industry has recently shown increased interest in the use of unmanned aerial vehicles (UAVs) to assist in everyday operations [20, 11, 4]. Above ground, small UAVs are in some cases a more efficient, inexpensive, and safer alternative to manned aircrafts currently used for photography, inspection and security [6, 10]. For example, attaching camera, infrared and LiDAR payloads, UAVs can provide a low-cost method of obtaining highly accurate 3D photogrammetric data and aerial photography. UAVs are now commonly used in open pit mining operations for applications that include stockpile surveying, 3D pit modelling, facilities management, accident reporting, progress monitoring, and environmental assessment [11]. There are numerous companies offering UAV services for mining applications; e.g., UAV Geomatics, Leica Geosystems, Sky Futures, SenseFly and FlyTerra, to name just a few. Common services include stockpile and open pit volume computations, environmental assessment, aerial mapping and photogrammetry. Although the aforementioned services are thosemost commonly provided by UAV surveying companies, they may also add value to other daily mining operations. For instance, SenseFly offers pre and post-blast monitoring in order to identify the presence of misfires and wall damage. This data can also be used to reconcile the blast results with expected results. GEM Systems offers a UAV equipped with a magnetometer for mineral exploration surveys. Companies such as Barrick have even used UAVs for solids modelling at tailings dams and stability monitoring [11]. UAVs in mining have so far been mostly limited to surface applications. Harsh underground environments pose many obstacles for flying UAVs. The confined space, dampness, reduced visibility, air movement, and lack of control signal propagation hinders most operators from being able to fly a drone underground. It may be that truly practical uses for UAVs underground will require either autonomous or semi-autonomous flight capabilities. Although there are many difficulties with flying underground, the potential benefits from a working system could greatly improve mining operations. The potential benefits of deploying UAV platforms underground include access to unreachable and dangerous locations and removing personnel from unsafe situations. These benefits have the potential to greatly improve mine monitoring and mine safety. Research has shown that current UAV technologies exist that allow for autonomous indoor flight. Extensive research has been done to develop UAV systems that are capable of performing on-board simultaneous localization and mapping (SLAM), which can allow them to navigate and map a foreign environment autonomously [5, 7, 1, 13]. Grzonka [7] successfully used an open hardware quadrotor to autonomously navigate and map an office building. The research outlines the localization, mapping, path planning, height estimation and control of the autonomous quadrotor. Other research has been done that exploits autonomous UAVs for search and rescue. Kassecker [9] proposed a software and hardware framework for a quadrotor capable of indoor and outdoor urban search and rescue and Rudol [19] developed a system for human body detection and geolocalization using an autonomous UAV.The use of autonomous UAVs in search and rescue has the potential to improve situational awareness and surveillance for a rescue team. Similar research has been done that uses autonomous UAVs for indoor exploration. Pravitra [15] outlined a strategy for autonomous exploration of miniature air vehicles (MAVs) within indoor environments and Rudol [19] developed a method for using an unmanned ground vehicle (UGV) and a UAV for cooperative indoor exploration. These studies show that aut"

Jan 1, 2017

By S. K. Kawatra, S. K. Valluri, S. J. Root

Common carbon dioxide capturing reagents, such as amines and sodium hydroxide, are expensive, toxic, and energy intensive to regenerate. We have added frothers to a sodium carbonate solution in order to increase the surface area available for CO2 transport within the packed bed of a counter current scrubbing column. Addition of frothers has improved the performance of sodium carbonate scrubbing solutions to be on par with sodium hydroxide scrubbing solutions. This novel enhancement of a relatively inexpensive CO2 capture-regeneration cycle shows potential to allow plants to turn a profit by sequestering a waste product. These results are discussed in detail in the following manuscript. INTRODUCTION The combustion of fossil fuels converts chemical energy to thermal energy. CO2 is produced as a byproduct of the reaction. 80% of the world’s electricity is produced by using this thermal energy to power a generator, accounting for 40% of global carbon dioxide emissions. In an effort to stabilize the rising atmospheric CO2 levels, researchers are investigating the application of carbon capture and storage (CCS) systems in power plants. [1] Efforts to capture CO2 at some power plants have been successful, but the cost of installing and operating the required equipment is high. As such, very few power plants have CCS systems. If CO2 can be captured and processed into a product that can be sold at a profit, installing CCS systems in power plants will be a very attractive business decision. In order for the sale of captured CO2 to become a profitable venture, the cost of capturing the CO2 from a flue gas must be reduced. BACKGROUND The most common method for separating CO2 from a flue gas is by passing it through a counter-current packed bed scrubbing column. The flue gas enters the bottom of a column while a solution of a chemical with properties advantageous to the absorption of CO2 is pumped to the top. The fluids interact in a packed bed, where the CO2 is transported from the gas to the liquid. CO2 is an acid gas, so it is common for the scrubbing solution to be alkaline in nature in order to neutralize the carbonic acid that is formed when it is dissolves into water. The exhaust exits the top of the column free of carbon dioxide, which exits the column in the scrubbing solution, reacting or complexing with the absorbent. Figure 1 is a schematic drawing of a CO2 scrubbing column. It shows the molar flowrates and compositions of the gas and liquid at the bottom [1], the top [2], and an arbitrary height in the column [Z]. [2,15] L is the molar flowrate of liquid at any point in in the column. G is the molar flowrate of gas at any point in the column. Since the CO2 is transported from the gas to the liquid, L and G are variable with respect to height. To simplify calculations, the CO2 free molar flowrates Ls and Gs are often used. X is the fraction moles of aqueous CO2 per mole of CO2 free liquid. Y is the fraction moles of gaseous CO2 per mole of CO2 free gas. Figure 2 is a composition diagram of the scrubbing column depicted in figure 1.

Jan 1, 2019

By W. L. Hollinshead

For more effective and cost saving production in tunnels, the machinery used on construction sites will be equipped with guidance systems combined with working procedure management systems. This paper describes sensors for these systems and various system configurations. A project is described which uses a computerized guidance system on an underground mining machine for guidance and profile control.

Jan 1, 1999

By Walter E. Heinrichs

To many, petroleum exploration and successful geophysics , are partly synonomous, This is not because natural petroleum is usually concentrated as a liquid, nor certainly not because oil can be detected directly. The reason is Chat geophysics helps to at least better understand and sometimes, to even explain the essential geology involved. That groundwater is similarly a liquid with all but a few of its basic geologic relationships practically identical to petroleum, seems to have escaped many of those most interested and responsible for complete geo-hydrologic knowledge. The paramount need to use every means at our disposal for maintaining and expanding our crustal resources reserves are generally obvious, However, in view of the rapidly mounting requirements, continual re-emphasis is worthwhile.

Jan 1, 1963

By Russell. A. Smith

This paper describes some recent work on the identification and development of new chemical reagents aimed at improving the industrial processing of phosphate ores by froth flotation. In particular, three chemical product families which will be discussed appear to offer enhanced flexibility by: 1) utilizing a small amount of a silica control reagent which can significantly reduce the amount of anionic (carboxylic) collector required for a given P2O5 recovery level; 2) utilizing a new anionic collector family which offers high P2O5 recovery and selectivity versus standard carboxylic collectors; and 3) utilizing another new anionic collector family which has, in some tests, allowed for selective removal of dolomite from apatite. Examples and use characteristics of each of these new chemical ideas will be presented.

Jan 1, 1993

By John G. Reid

Geologists, employed by the Australian Company, Metals Exploration Limited, discovered nickel laterite enrichment at Greenvale in 1967. A joint venture was arranged with the Freeport Minerals Company who had gained early experience with nickel laterite ores when building and operating the Nicaro and Moa Bay Treatment Plants in Cuba. A 5 tonne/day Pilot Plant at the Freeport research facilities at Belle Chasse, Louisiana, verified the amenability of the ore to treatment by the reduction and ammonia-ammonium carbonate leaching process used at Nicaro. A 5 800 tonne/day Treatment Plant was constructed on the coast at Yabulu, North Queensland. This paper describes the ore body, the mining operation and the stages of treatment required to produce nickel oxide products and a mixed nickel/cobalt sulphide product at Yabulu.

Jan 1, 1979

By K. H. Bettles

The Goldstrike Mine is in Eureka County, Nevada, approximately 23 miles northwest of the town of Carlin. The mine is at the north end of the Tuscarora Spur of the Tuscarora mountains at elevations of 5,300 feet to 5,950 feet. It is part of the Bluestar/Goldstrike subdistrict of the Carlin Trend of sediment hosted, disseminated gold deposits. The Carlin trend comprises over 15 major gold deposits with production, reserves and geological resources of approximately 50 million ounces of gold (Fig. 1). In the Bluestar/Goldstrike subdistrict, there are four major deposits; Post, Betze, Bluestar, and Genesis, plus numerous smaller deposits (Fig. 2). Betze is located on property controlled by Barrick Goldstrike Mines; Bluestar and Genesis on Newmont Gold property; and Post on both Barrick and Newmont property.

Jan 1, 1989

By P. C. O. Chukabarah

Many aerodynamic and thermodynamic properties, such as temperature, pressure, velocity and density vary widely, and in random spatial and temporal manner for a given underground mine environment. Such variabilities are seldom evaluated statistically, even though the relevant theories and principles for such an approach are both available and feasible. The main purpose of this paper was to introduce the new methodology of applying aerostatistics to the analysis of multiple fan system in mine aerology and/or ventilation. Pertinent data were obtained from a small multilevel coal mine. Results proved and confirmed that aerostatistical methodologies are computationally more efficient, grounded in solid engineering statistical theories, and can be used to analyze networked parameters in mine environmental engineering.

Jan 1, 1994