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By Yi-Hsuan Chen, Jürgen Brune, Candace S. J. Tsai, Alejandro Munoz, Connor Krause

This study highlights the significant presence of submicrometer- sized airborne particles in underground coal mines, especially around the belt conveyor drift areas. Using realtime instruments and gravimetric samplers, the assessment revealed that particle concentrations were notably higher in the belt entry compared to other locations, with a strong presence of submicrometer- and nanoparticle-sized dust. The study’s findings emphasize the importance of addressing small particle exposure, as these particles, composed of harmful substances like calcium, copper and iron, can pose serious health risks to miners. This research emphasizes the importance of improving air exposure estimation through more effective monitoring and characterization techniques to better understand and reduce workers’ exposure to hazardous airborne particles in the mining environments.

Apr 1, 2025

By Firat Atalay

Estimating the spatial distribution of ore grade is one of the most critical steps to proceed with an investment decision on a deposit. Kriging is the most widely used method to estimate the ore grade, but alternative techniques are being developed. Machine learning algorithms can be used as alternative methods to classical kriging. In this paper, the iron (Fe) grade of a deposit is estimated with the XGBoost algorithm, and the results are compared with kriging estimation results. For the estimations, samples collected from drillholes were used. Due to the different natures of the estimation methods, different steps were taken to perform the estimations. The results show that XGBoost produced higher-range estimates, which is a desired result in ore grade estimation, and the minimum and maximum of the estimates were lower and higher than the kriging estimates, respectively. However, like kriging, the estimation results were smoother than composites, and the variance of the XGBoost estimates was lower than the variance of composites. This means that even though estimation with XGBoost mitigates the smoothing effect, the estimation results suffer from smoothing like kriging.

Dec 1, 2024

By M. Sandin

According to the world bank1, the mining industry consumes up to 11 percent of global energy use. In comparison, 70 percent of mining projects from the six largest mining companies operate in water-stressed regions. To steer the direction of the process industries toward more sustainable practices, more than 40 governments have adopted a price on carbon. This measure includes additional taxes on the use of fossil fuels, trade programs, new standards for renewable energy, energy efficiency mandates, more stringent emissions regulation, carbon offsets, etc. This emphasis is also supported by investors shifting their priorities to reduce risk by focusing on long-term plans, including environmentally friendly operations. The metals and mining industry is at the core of the green energy mix and electrification of vehicles. This new trend creates an astronomical increase in demand for minerals. Under a 2-degree scenario, according to the latest analysis from the world bank, as new energy technologies continue to grow, it is expected that all minerals to double in demand, and the distribution of these materials will depend on their application. • Solar panels, will account for 87% of the aluminum demand, and more than 95% of silver • Wind turbines and geothermal plants will require 98% zinc and 64% titanium. • Solar and wind energy alone will demand more than 74% of the global supply of copper, and this is without considering wiring or other infrastructure to connect the grid • Battery storage accounts for 100% of the graphite and lithium demand. (Hund, 2020) • Other materials, such as nickel and steel, are also projected to more than double in demand as they are cross-technology minerals. These materials require a manufacturing process that is accountable for the emissions proper of the transformation process. It requires that these processes move from a hindsight mode focused on reporting to a forecasting mode based on run-time measurement of GHG emissions. This is a critical first step in companies realizing an economic return for doing the right thing for the environment and their communities.

Feb 1, 2023

By Issac Douglas, Sheila Devasahayam, John S. Thella, Manoj K. Mohanty, Jeremy Prishmont

The flotation performance of Sodium O, O-diisobutyl Di thiophosphate (referred to as reagent A) was compared with Aerophine 3418A (referred to as reagent B) for floating a complex copper ore grab sample (Ore A). Preliminary test results indicated a cumulative copper concentrate grade of 10.19% with a recovery of 86.31%, which was achieved with reagent A from a feed consisting of 5.32% Cu. The grade and recovery achieved using reagent B are 9.11% and 87.85%, respectively. A comparative analysis based on the preliminary test results indicated that reagent A’s performance is better than that of reagent B at lower concentrate grades, specifically below 12% Cu. However, the flotation performance is better for reagent B at higher concentrate grades (>12% Cu). A more detailed study was conducted to optimize the grade-recovery performances achievable from both reagents on a complex low-grade copper ore sample (Ore B) from Western USA. Test results indicated a copper concentrate with a grade of 5.5% Cu and 78.59% recovery was obtained with reagent A compared to 4.31% Cu and 62.04% recovery with reagent B from a feed consisting of around 0.25% Cu.

Feb 22, 2026

By V. O. Tenorio, K. W. B. Requist

As the mining industry begins efforts to examine the feasibility of extraterrestrial resource utilization, the extraction and processing of icy regolith containing water and other volatile materials will be the initial focus for future expansion of capabilities. Pure water is essential for human consumption, and a source of oxygen and hydrogen. The latter, along with the volatile materials, lend themselves to the creation of fuels that may be used for further space exploration at distances not currently feasible. For any extraterrestrial scoping project, the transport of materials to geoscientists remains virtually impossible. Therefore, analysis must be done in-situ, possibly millions of miles away from the nearest human. To address the need for geologic resource estimation in the absence of geoscientists, an infrared framework has been developed for the analysis of water ice content in simulants of permanently shaded lunar regolith. This framework relies on a convolutional neural network model for the rapid analysis of percent water ice content in samples, at which point standard geostatistical methods may be employed.

Feb 1, 2023

By E. B. Graves

I have been asked to talk to you this morning about phosphate marketing and distribution. In discussing this I will attempt to answer such questions as: What is phosphate? Where do we get it? What form is it and how do we sell it? How do we distribute it? How is it applied? And last, but not least, What about the future? To start with, phosphate is one of the three primary plant nutrients. It is the element essential for root structure of plants. Plants, like humans, need a balanced diet. Thus, the amount of phosphate required by individual plants is, in part, related to how much of the other nutrients are used. Virtually all soils contain a certain amount of available phosphates. Back at the turn of the century the most common source of additional plant nutrient, including phosphates, was from cattle manure. The use of chemical fertilizers is something that has grown significantly during the last half century, and in particular, the last 20 years.

Jan 1, 1977

Software exhibitors at MINExpo will feature the newest, the best, the most comprehensive computer-based tools available to get minerals from the ground to the market. From the ?cloud? to the pit, the variety that will be featured is almost limitless ? a digital tool for every phase of the mining lifecycle. Blue Sky Network SkyRouter brings the Blue Sky Network to the cloud. Using its interactive Web portal, SkyRouter, with detailed mapping and integration with Google Earth, the Blue Sky Network links enterprises to personnel and assets anywhere on earth through Iridium satellites. The cloud-based solution is designed to support connectivity with remotely dispersed mobile assets, including Blue Sky?s dual-mode GSM and Iridium tracking and communications services. This enables seamless connectivity with assets in problematic cellular reception areas, where only 10 percent of the Earth is covered, and in remote locations.

Jan 1, 2012

By A. Gungor

Thermal treatment can significantly improve industrial comminution operations by reducing energy requirements and increasing mineral liberation. The assistance of thermal pretreatment prior to grinding by microwave heating is scrutinized in this study. For this purpose three copper ore samples with different chemical composition were used. To see the effect of microwave heating on ore; work index, breakage rate and breakage distribution functions of original and heat treated samples were examined. The results obtained in this study did not show significant improvement in the grindability characteristics of the studied ores with microwave heat treatment. The inadequate amount of microwave transparent matrix was the main reason for the absence of cracks and micro-fractures in the microwave heated copper samples.

Jan 1, 1999

By J. E. Bevan

Once mining compromises the stability of a rock mass, the dangerous task of roof bolting begins. Many attempts have been made to automate this process, but there are still many refinements that need to be made. In the past, roof bolting modules were designed around the abilities of a human operator. Currently, researchers are taking a new approach that focuses on designing modules that can utilize bolting methods that are easily automated. A non-rotating anchor that is locked into position by a linear force (as opposed to a rotational force) was designed by researchers at the U.S. Bureau of Mines. Once the bolt is secured in the bolt-hole by the anchor, the bolt is tensioned and a collet is used to secure the other end of the bolt. This process replaces the traditional bolt-nut fastening method. This program is part of an effort at the U.S. Bureau of Mines to automate the coal mining process.

Jan 1, 1994

By J. G. Groppo

A beneficiation process has been developed to provide selective separation of unburned carbon from high LOI fly ash. Previous reports of utilizing froth flotation to achieve selective separations required long residence times and high reagent costs. A proprietary reagent system has been developed to address both of these limitations. Based on the results obtained from laboratory and pilot-scale investigations, a flowsheet design has been developed to produce two distinct usable products from class F fly ash; low LOI ash and a high carbon product suitable for reburning or further upgrading. A process flowsheet and description are presented.

Jan 1, 1996

By Abdullah Arik

Verification of computer generated reserve models is essential since the computer does not automatically check the validity of methods and assumptions selected by the user and their results. For the computer to do model verification would require an expert system which would perform tests on the model and determine if the model is valid. Since such an expert system is not available, it is up to users to verify the models they develop.

Jan 1, 1995

By K. J. Sollman

As a class, silicate minerals have likely found the broadest, if not largest volume, use in combination with polymeric binders of all industrial minerals. Among the silicates, calcium metasilicate, wollastonite, enjoys a front runner position in a near universal sense. It is a viable and desirable part of composites ranging from thin films to large moldings; from a common filler/extender for paint for your garage to a reinforcement for the exterior surfaces of a luxury vehicle affordable to very few. This article is focused upon the variations in particle morphology and the surface characteristics which, by way of commercial examples and discussion of active research programs, make this environmentally benign mineral so unique.

Jan 1, 1993

By Kang-Hyun Kim, Ho-Jong Kim, Jong-Ho Shin, Hoon-Ki Moon

"In urban areas, it is often required to construct additional railway tunnels beneath existing railway tunnels. In this case, dynamic interaction between tunnels at the intersection becomes an important issue, as it amplifies structural behavior causing damage to structures and inconvenience to passengers. In this study, vibration superposition effect at the intersection between existing and newly constructed tunnels is investigated by the numerical method. Dynamic interaction mechanism is firstly examined using simple sine wave load, and then a typical analysis for actual multi-leveled tunnel intersection is performed. The results show that the dynamic amplification due to dynamic interaction of tunnels is 149% at the crown of lower tunnel. This indicates that the vibration superposition effect must be considered when the planning and design of a new tunnel beneath the existing tunnel. 1. INTRODUCTION In these days, there are increasing cases that trains cross without transfer stations in metropolitan areas. Consequently, either tunnel is necessarily to be neighboring or crossing, thus tunnel sections closely located are created as shown in Figure 1. If a new tunnel is constructed beneath the existing tunnel, the vibration due to trains passing through each tunnel can mutually affect. The behavior of coupled vibrations may occur and exceed the allowable structural limit, and cause inconvenience to passengers. Theoretically, when vibration waves are propagated from a source to different locations, amplification or decrease of the vibrations can occur by the principle of wave superposition and interference. Multi-leveled tunnel intersection is one of the cases mentioned above. In the actual tunnel, it is difficult to investigate the vibration superposition effect due to a complex ground conditions and structural geometries. In addition, train vibration itself is multi-source vibration, which cannot be theatrically analyzed. Thus, at the tunnel intersection, train vibration from two tunnels make the problem more complicated."

Jan 1, 2016

By B. A. Wills

Much research effort has been spent in attempting to reduce the high energy costs in grinding, but relatively little in developing methods to enhance the liberation of the minerals from each other. This paper presents some ideas on the nature and role of grain boundaries in mineral assemblies, and their influence on the propagation of cracks through the rock. It is argued that if the mechanisms of fracture are more clearly understood, crack propagation may be controlled in such a way that intergranular fracture dominates breakage, producing less fines and a higher degree of liberation.

Jan 1, 1995

By E. J. Wasp

The transportation of mine products incurs a cost which can have a significant bearing on the competitive position of the manufactured product. Clearly, the engineer who is responsible for selecting a mode of transport must base his decision, at least in large measure, on economic comparisons. And today, the engineer usually finds that he has to choose between several modes, including slurry pipelines. For the purpose of an initial economic screening, it is not necessary to go deeply into the technical details of a slurry system. What is usually needed, however, is a method with which the engineer can make a quick economic assessment to determine whether a slurry pipeline should be included in the detailed final analysis. This paper presents a rapid method for making such a preliminary appraisal. Experience with commercial slurry pipeline systems in several countries and with a variety of solid materials has shown that if several assumptions pertaining to critical design variables are made, it is possible to roughly estimate the transportation cost of a slurry system on the basis of only three factors: the specific gravity of the solid material, the length of the system, and the quantity of slurry to be pumped each year. It is assumed that conditions pertaining to field construction, corrosion inhibition, and the like, will be favorable. This assumption is critical because any factor which analysis shows to be particularly unfavorable will raise the total transportation cost estimate which this paper establishes. If the engineer employs this estimating procedure and decides that the use of a slurry pipeline is economically unattractive, his chances of being wrong are small. Conversely, if his quick appraisal indicates that the use of a slurry system is economically favorable, the engineer is justified in committing the time and money needed to make a more detailed investigation of the slurry pipeline potential.

Jan 1, 1969

By L. A. Henry

The island of Jamaica consists predominantly of Carbonate rocks which vary in chemical & physical characteristics. Currently these rocks are used for construction and road aggregate, landfill and as a raw material in the manufacture of cement. Over the past fifteen years the Geological Survey of Jamaica with assistance from a number of international aid agencies and the private sector have identified deposits of high calcium/high brightness limestones which have the potential to be utilized as a high quality filler and a number of other commercial applications. Geologically, these limestones are formed within the Eocene Swanswick Formation, the Oligocene Walderston-Browns Town Formation and to a lesser extent the Miocene Montpelier and Newport Formations.

Jan 1, 1998

By D. C. Ridenour

The pressure system of ventilation with large diameter bore holes has been very effective in the ventilation of two gaseous mines, the Olga No. 1 and No. 2 Mines in McDowell County, West Virginia. The No. 4 Pocahontas Coal Seam on the Olga property lies 580 feet below the valleys. The seam is very gaseous as well as dry and dusty, which makes good ventilation all the more essential. Irregular and often extensive areas of the coal seam have been replaced with impervious shales and sandstones in "Fault" or "Want" areas. The replacement materials have sealed the methane in the coal seam and thus increased the quantity of gas that must be handled as mining is done. Often the No. 5 Pocahontas Seam comes down to meet the No. 4 Seam at the Faults and considerable methane is sometimes released from the upper seam. The factors mentioned, together with the irregular and unpredictable lateral shape' of the faults, result in long narrow stringers of coal that are very gaseous and difficult to mine. So far as the Olga Coal Company is concerned, the most effective ventilation under the conditions outlined has been the use of large diameter bore holes with a pressure ventilation system. The ventilation of a mine can be accomplished in two fundamental ways. The mine atmosphere maybe reduced below atmospheric pressure by an exhaust fan; or it may be raised above atmospheric pressure by a pressure fan. In either case, the coursing of the air is so planned as to have the haulage and traveling ways on intake air. While the majority of the coal mines in the United States, no doubt, use the exhaust system of ventilation, there are several advantages of the pressure system which are extremely beneficial.

Jan 1, 1960

By Robert Walker

The win theme of this session is Unique Material Handing Systems. The theme was selected because of two major factors. 1. Accomplishments of unique character manage to attract interest regardless of their age. 2. There is much to be learned from pioneering efforts of the past as they are the stepping stones to technological development. Thus, 2-1/2 years after completion, the engineering feat of Oroville Dam still looms large let us take a close look at this project to see what made it unique. To begin with, it established a number of firsts: At 770 feet it was the highest earth fill dam in the world. At $121 million dollars, it was the largest ever United States construction project (Civil). At 80 million cubic yards it had the largest earth volume of any dam in the world. The extensive use of belt conveyors for this application had never before been tried. The use of a high capacity bucket wheel-excavator with shiftable belt conveyors had never before been utilized as a con¬tractor's tool. The principal of the "integral train" was applied most effectively whereby up to 220,000 tons of material-was transported daily some 14 miles. To achieve optimum economics a number of technical breakthroughs were necessary. The suppliers of major commercial components worked hand-in-hand with system engineers to develop new machinery necessary for the highly mobile characteristics of the systems, viz., single pulley drives delivering 2000 horsepower, 1000 horsepower right-angle shaft-mounted reducers, across the line starting of 1000 horsepower squirrel cage motors, 10 miles of steel chord conveyor belts with belt tensions up to 150,000 pounds, aircraft-type disc brakes, hydraulic take-ups, train loading at a rate of 25,000 tons per hour, automatic train indexing for rotary dumping at 10,000 tons per hour, roll-over car dumping without uncoupling cars, shifting 7500 ft. long conveyors up to 300 feet laterally without disassembly. These are some of the superlatives that have made the Oroville Dam project unique. The measure of its success is demonstrated by the results.

Jan 1, 1970

By D. A. Ellis

This paper review s several new applications of solvent extraction developed in conjunction with a research project carried out under the AEC Raw Materials Division by the Dow Western Division laboratories during the last two years. A process for recovery of uranium from ores by contacting the solid directly with organic solvent without a prior aqueous leach and a process for uranium recovery by contacting thick, unfiltered leach slurry with the solvent were studied in an attempt to simplify ad reduce the cost of ore treatment procedures. Processes to produce pure UF4 products at the concentrate mills thus eliminating the production and subsequent dissolution of the concentrate were investigated. Since many of the leach liquors contained vanadium as well as uranium, solvent extraction processes for by-product vanadium were also studied.

Jan 1, 1958

By Leonardo Rosas Sánchez, Darío Ángel Bulla

"The two track road sector between Cisneros-Loboguerrero (having a length of 14 km and 11 short unidirectional tunnels) is a new highway still on construction located along the existing Highway Buga – Buenaventura (Colombia). Due to the steep topography, difficult geological/geotechnical conditions, the traditional portal construction approach was impossible to be implemented in eleven (11) of the twenty two (22) portals. In this specific project, the skewed portal approach was developed as the optimal and more effective solution. The construction time and costs of portals were reduced in 21 months and 75%, respectively. At the same time, the natural equilibrium of the slopes was maintained, thus, facilitating adequate safety factors along the useful life of the project. This document pretends to show a detailed design experience (and the construction of the entry portal of tunnel 11 (left)). INTRODUCTION The Cisneros-Loboguerrero project is a 14 km length dual lane highway, connecting productive zones with the Pacific Ocean along the current Bogota-Buenaventura highway as shown in Figure 1. The project is located at the northern side of the Dagua River Valley. The preliminary design suggested constructing portals under challenging topographical conditions, i.e., slope cuts having heights between 50 to 100 m (some having slopes > 100%) requiring complex developments and having very high risks.The entry portal of tunnel 11 (left) was the first portal successfully built by implementing the skewed portal approach. Later, this approach was used as a model for the construction of the other ten (10) portal having similar topographic and geotechnical conditions. The development of this new alternative provided a considerable reduction on the construction time of portals, thus relieving a critical path in this project."

Jan 1, 2016