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By William G. Doepken

With most of the mining industry emerging from the deepest business recession in 50 years, primary attention must be given to surviving in a business climate where dominant foreign competition, depressed prices, and potential overcapacity hang heavy over much of the industry. While already shackled with regulatory constraints, restrictive work rules, and high labor costs, mine operators are faced with the difficult task of reducing costs and improving productivity while operating at less than full capacity. To counter these nearly over-whelming factors, the mining industry must continue at the national level to seek regulatory relief and a rational policy toward foreign competition from government-controlled mines. In addition, dialogue with labor organizations must continue to minimize the impact of labor costs, cost escalators, and antiquated work practices. Although national and international actions have a tremendous impact on the future of domestic mining operations, local actions by mine operators to dramatically improve mining productivity will strengthen the industry's competitive stance. Before any substantial progress can be made, however, mine operators must recognize and define areas that depress productivity and establish goals and measures for improvement. Once problem areas are defined, a combination of technological and motivational concepts can be applied to improve productivity. Timing of Improvements While there is an immediate need for productivity improvements, only certain concepts offer near-term improvement potential while others must, of necessity, fit into a mid-range or long-range time frame. Near-term solutions (immediate to one year) likely will involve motivational concepts - work incentives and training - coupled with available technological concepts that require little capitalized development or site testing. Mid-range solutions (one to three years), by contrast, will include technological improvements in mining equipment, techniques, and systems automation. These concepts require a longer period of capitalized development and site testing before use. Long-range solutions (three years or more), which include adoption of new mining methods and computerized control systems, will appear only after prolonged research and capitalized development programs. Motivational Improvements Developing motivational con-

Jan 11, 1983

By M. R. Shahan, C. E. Seaman, S. E. Mischler, T. W. Beck

"Float dust deposits in coal mine return airways pose a risk in the event of a methane ignition. Controlling airborne dust prior to deposition in the return would make current rock dusting practices more effective and reduce risks of coal dust-fueled explosions. The goal of this NIOSH study is to determine the potential of open-air water sprays to reduce concentrations of airborne float coal dust (<75 µm diameter) in longwall face airstreams. This study evaluated unconfined water sprays in a featureless tunnel ventilated at a typical longwall face velocity. Experiments were conducted for two nozzle orientations and two water pressures for hollow cone, full cone, flat fan, air atomizing, and hydraulic atomizing spray nozzles. Gravimetric samples show that airborne float dust removal efficiencies averaged 19.6 percent for all sprays under all conditions. The results indicate that the preferred spray nozzle is operated at high fluid pressures to produce smaller droplets and move more air. These findings can be used to select sprays and design spray arrays to control airborne float dust over the entire longwall ventilated opening. INTRODUCTION Coal mining processes produce airborne dust that naturally deposits on the floor, roof, and ribs of mine airways. These fine dust particles, termed float coal dust when smaller than 75 microns in diameter, are deposited in return entries of coal mines and can be re-entrained by pressure waves induced by methane-air explosions (Rice et al., 1911; Nagy, 1981; NIOSH, 2006). These particles are also those most likely to participate in coal dust-fueled explosions, which can potentiate and propagate explosions resulting in extensive damage. In order to meet compliance requirements of at least 80 percent incombustible content in the composition of material deposited in mine entries (CFR, 2016), coal mines apply an inerting agent, specifically, rock dust (Harris et al., 2009). Should methane be present in the mine atmosphere, the required fraction of incombustible content is further increased by 0.4 percent for each 0.1 percent methane. The removal of airborne float coal dust (AFCD) prior to deposition is an approach intended to make current rock dusting practices more effective by increasing the proportion of inert material to combustible material, resulting in a lower risk of coal dust-fueled explosions. Water sprays are both effective and widely accepted as a method for controlling underground coal mine dust. In fact, water sprays are considered to be the most economical and technically feasible means of reducing dust concentrations in underground coal mines (Courtney and Cheng, 1977; Barker and Humphreys, 1996). Sprays are used in several ways to control dust in mining processes: inhibiting dust formation, immobilizing dust to prevent it from becoming airborne, and capturing airborne dust (Cheng, 1973). Reductions in airborne dust concentrations have frequently been attributed to inertial impaction between water droplets and dust particles, forming larger agglomerates which then quickly precipitate out of the airstream (McPherson, 1993). Inertial impaction activity is generally accepted as the major capture mechanism for airborne particles larger than 0.5 µm in diameter. It is this mechanism that is evaluated in this study."

Jan 1, 2017

By Michael MacMillan

The mining industry has always operated under intense public scrutiny. Community expectations, investor pressures, regulatory obligations, and environmental oversight create a uniquely complex communications environment. In recent years, technological change, climate urgency, and geopolitics have reshaped how the industry communicates its role and value. The rise of artificial intelligence in the information ecosystem represents yet another fundamental shift. As AI evolves, an organization’s reputation will no longer be shaped solely through human interactions, media coverage, social activity, or corporate disclosure. Increasingly, public understanding depends on how AI systems interpret and represent company information. These systems influence search results, conversational tools, news aggregation, social discourse, and even investor intelligence platforms. As AI-generated summaries, answers, and narratives become the default interface for stakeholders, they also become authoritative in shaping trust. For mining companies, this creates both risk and opportunity. The organizations that recognize how AI reads, prioritizes, and amplifies information will be better positioned to build trust. Those that remain silent or rely on traditional communication methods may find their reputations being algorithmically defined without their participation. This paper explores how mining companies can proactively engineer their reputations in the age of AI.

Jan 1, 2026

By K. R. Griffin

Atmospheric conditions underground are constantly changing and from a safety perspective, it is critical to identify when conditions are trending abnormally. Atmospheric monitoring in underground coal mines allows mine operators to analyze atmospheric conditions underground in real-time. Real-time monitoring can then be used to identify whether atmospheric conditions underground have become problematic. The implementation of a risk assessment and management process allows operators to then use a risk-informed decision making to identify comprehensive site specific ventilation parameters. Establishing risk-informed ventilation parameters and tracking conditions relative to these parameters, management can modify ventilation plans as mine conditions develop to manage evolving risks. Ventilation risk assessment and management allows developing atmospheric monitoring technologies to be fully utilized in order to increase safety standards in the United States. This paper reviews general risk assessment approaches, state of the art ventilation based risk assessment, and the risk assessment and management application within the United States regulatory framework.

Feb 27, 2013

By T. R. Ellis

Many appraisers/valuers believe that the only valuation method available within the Cost Approach category for Real Property appraisal is the depreciated replacement cost method. Some valuation and financial reporting standards setters also believe the same. This paper introduces the minerals appraiser to a number of useful methods for mineral property appraisal that are based primarily on the principle of contribution to value, the predominant economic principle in the cost approach. Most of these cost approach methods discussed are primarily for use in valuation of exploration tracts and resource properties that have no defined reserves. However, the powerful rural cost method can be used to calculate the contribution of categories of resources, reserves, and other property components to the value of a mineral property. This method can be applied to mineral properties at all stages of development, including producing properties.

Jan 1, 2011

By E. M. Abraham

The establishment and survival of different grass species and cultivars on various phytotechnic treatments at a limestone quarry was studied. The treatments applied were: a) bare soil, b) bentonite, c) bentonite-straw and d) asphalt-straw. According to the results, significant differences were found among species and cultivars, growing on different treatments as far as plant growth and survival are concerned. The seed germination was higher on bentonite -straw and asphaltic-straw than on bentonite but the plants survival were higher on bentonite. Lolium perenne had higher seed germination rate and better establishment than the other tested species at all treatments. However, the survival rate of Agropyron desertorum and of the cultivars palestina and chrysopigi of Dactylis glomerata was higher than of the other species.

Jan 1, 2007

By C. K. Man

Coal dust explosions in underground coal mines are prevented by generous application of rock dust (usually limestone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents flame propagation by acting as a thermal inhibitor or heat sink. To investigate this process in more detail, a number of explosion experiments using various coal dust and limestone rock dust mixes have been carried out at the Lake Lynn Experimental Mine (LLEM). These were conducted in a single entry of about 1600 ft (488m) in length and initiated with a methane gas explosion. A consistent set of post-explosion floor dust samples were taken along the entry after each test. These dust samples have been analyzed in the laboratory using thermogravimetric analysis (TGA) and solubility to determine how the limestone rock dust behaved during the coal dust / rock dust explosions. The preliminary results are reported in this paper and indicate that the chemistry of limestone plays an important role in its capacity to inhibit coal dust explosions. The results also show that it may be possible to estimate the intensity of the explosion using these conventional methods of analysis. Disclaimer: The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.

Jan 1, 2009

By R. Oler

The mining industry?s traditional preference for protective coatings in corrosive environments, due to cost considerations, has been to apply galvanized and epoxy coatings. As a result of extreme pH levels and the limitations of current products, a new coating has been developed to withstand severe conditions. Harsh chemicals and corrosive groundwater pose added challenges to mines in maintaining long term ground support which demands continuous rehabilitation. This paper highlights the challenges and identifies a solution by applying a new economic coating to DSI?s Omega Bolt? that withstands the most corrosive of conditions. [ ]

Jan 1, 2012

By C. J. Hall

I would like to congratulate Professor Gershon on an idea that is obviously valuable and is certainly new to me. It has, however, to be further developed, in that one can get fallacious results by limiting oneself to positional weights. In the example problem, the positional weight of one block was 8.6 (the 8.0 value in the paper was incorrect) for 36 units in the cone, for a mean block value of 0.239. The positional weight of the second block was 4.4 for 15 units, for a mean block value of 0.293. Surely one would expect the second block to be rated higher. Additionally, the time value of money adjustment cannot be determined by depth, because the time that a block is mined is determined by the mining sequence, not depth. Figure 1 shows a slightly altered version of Professor Gershon&apos;s pit. The overall value of the pit is the same, as are the total values under each of his blocks. The values in the right-hand cone have been reversed top to bottom, and the values in the rest of the pit adjusted to keep the central cone total unchanged. All values have been multiplied by 10. Figure 2 shows the sequence of mining, at three blocks per year, for Professor Gershon&apos;s pit, and Fig. 3, the sequence for a pit under the other block. Table 1 shows the value and discounted value (15%) of Professor Gershon&apos;s pit, and Table 2 shows similar values for the second pit. It is apparent that the second pit schedule is more valuable than the first.

Jan 1, 1988

By Y. Nien Wang

The Devil?s Slide portion of Highway 1 between Pacifica and Montara is often closed due to the instability of the adjacent slopes. Following many years of public input and careful evaluation of alternatives, Devil?s Slide will be by-passed via two inland tunnels, providing a safe, dependable highway between Pacifica and Montara. For the twin tunnels, each 9m diameter tube will accommodate only one traffic lane. Each tunnel tube will accommodate a 3.6 meter roadway, 0.6 meter and 2.4 meter inside and outside shoulders respectively, and 1.2 meter walkways on each side. Cross passages will connect the bores at about 120 meter intervals and jet fans will provide tunnel ventilation. The twin tunnels are approximately 1,250 meter long and 9 meter wide. Excavation will progress from south to north using tunneling techniques that rely on inherent rock strength for support known as the New Austrian Tunneling Method (NATM). Both tunnels will be excavated at the same time, one tunnel face approximately 40 meters ahead of the other. Staggering the tunnels reduces the likelihood of damage from blasting in alternate tunnels. The work schedule is 24 hours a day, 7 days a week resulting in a 24-month timetable to break through to the north portal.

Jan 1, 2008

The new generation of computer environment provides mineral processing plants with convenient tools to store and retrieve or to analyze on-line process variable values as given along time by the various sensors installed in the plant. The paper describes the application of classical tools, such as time series analysis, to retrieve the hidden information contained is such data. The concepts used in single signal processing (autocorrelogram, power spectrum, ARIMA descriptors) and multi-signal processing (cross-correlogram, cross-spectrum) are briefly reviewed. Some examples are given to illustrate their application (sampling, data filtering, process behaviour prediction, process evaluation, data synchronisation). Examples are taken from mixing, flotation and leaching processes.

Jan 1, 1990

By J. Duran

Mining at Newmont Mining?s Phoenix?s Mine is currently done by surface operation in the Fortitude and Bonanza pits at a combined rate of approximately 100 kt/d (110,000 stpd). A portion of the orebodies targeted by these pits was mined previously by underground mining methods, dating back to the mid-to late-1800s. Most of the underground workings (voids) are located in the west central area of the Bonanza pit. The surface operation requires excavation through voids, and there is a risk of pit floor subsidence that has to be addressed. This article presents a review of the risk mitigation measures that were implemented to reduce risks to people and equipment working in the area.

By P. S. Baker

CRU estimates that the global supply of metallurgical grade alumina (MGA) grew by 5 percent during 2005 to a little more than 61 Mt (67 million st). About 30.7 Mt (33.8 million st), or 50.3 percent, of that originated from Oceania (principally due to the commissioning of the CAR refinery in Australia) and Latin America. In this context, Chinese production surged by 20.5 percent year-on-year to 7.7 Mt (8.5 million st) on the crest of a 17-percent rise in that country’s primary aluminium production. Meanwhile, on the demand side, there was a 6.7 percent climb year-on-year in global consumption to 62.3 Mt (68.6 million st). This reflected a healthy demand for primary metal from aerospace, construction, packaging and passenger transportation (to a lesser degree) in the United States, China, Brazil, South Korea and India. So there was an overall supply deficit of more than 1.2 Mt (1.3 million st). This, combined with an 18.3-percent diminution in closing stocks (down to 35 days of requirement), lifted the average spot price of MGA by 17.6 percent year-on-year to US$448/t (US$406/st).

Jan 1, 2006

By Lee Browne

The transformation of Peru’s Tintaya copper project from a state-owned company to a private company is under way and the results have been successful. Since Magma Copper Co. assumed operating management in December 1994, production and costs have improved dramatically. To understand the transformation of Tintaya, the transformation of Magma Copper must also be understood.

Jan 1, 1996

By G. Jalkanen

Parameter estimation of the inverse distance estimation algorithm is presented. The objective function to be minimized is a sum of squared cross validation errors. The unknowns to be estimated are the exponent of the inverse distance estimator and anisotropic angles and ratios that are used in determining the distances in the algorithm. Examples are presented for both two and three dimensions data sets.

Jan 1, 2009

By K. Oraee

Mining Ventures are considered as high risk projects and therefore managing the risks is inevitable. Risk assessment is an important part of the complex process of risk management, hence applying appropriated and practical methods for ranking the risks associated with projects, can help to perform a better risk management. In this research the applicability of using Techniques for Order Preference by Similarity to Ideal Solution (TOPSIS) method for risk ranking in an underground mine, extracting by block caving method, was studied. Via this method, the risk associated with reserve estimation ranked as the first while in conventional method (P-I Matrix method) located in the sixteenth. Also there were significant differences in ranks of the other risks. Considering the more criteria, with different weights, in comparison with conventional methods, the results comprised from TOPSIS method are more reliable. By implementing this method risks are ranked better and more realistic and consequently then will be managed more efficient.

Jan 1, 2011

By T. J. McKeon

Partition curves are used to evaluate the separation performance of gravity-based concentrators. The partition curve is used to identify the nominal density cutpoint and relative sharpness of the separation. In addition, the graphical representation makes it possible to quickly identify the root cause of misplacement based on the characteristic shape of the partition curve. Partition curves have been traditionally constructed using data obtained from float-sink tests using heavy organic liquids. These toxic liquids are environmentally unfriendly and have been banned in several countries. Another method of establishing the partition curve is to introduce density tracers into the feed and plot the distribution to the lights and heavies. For heavy mineral separations, this approach is generally impractical due to the fine particle size. In addition, the partition data obtained using these existing techniques do not account for secondary factors such as particle shape that may influence the separation. In light of these problems, a methodology was developed for constructing partition curves using experimental data obtained from microscopic grain-counts. This technique, which essentially uses the different mineral species as density tracers, provides a powerful tool for evaluating heavy mineral separations. A case study is provided to demonstrate how this analytical approach can be used to assess and improve the separaton performance in an industrial upgrade plant.

Jan 1, 2005

By R. E. Ray

In an effort to reduce the risks to underground miners of health hazards associated with exposure to high concentrations of diesel particulate matter(dpm), the Mine Safety and Health Administration(MSHA) published proposed rules in 1998 limiting dpm exposure in both underground coal and metal and nonmetal mines. The proposed rule for underground coal mines would require removal of 95% of dpm by mass, while the rule for metal and nonmetal mines would eventually limit total carbon exposure from dpm to 160 micrograms per cubic meter of air over an eight-hour shift. The comment period for both proposed standards ended on July 26, 1999.In this session, representatives from MSHA, the National Institute for Occupational Safety and Health (NIOSH), equipment manufacturers, labor and industry will discuss the impact of the proposed regulations on mine operations and worker health. Questions will be taken from the audience after brief presentations from each panelist. This paper provides a compilation of written summaries of each panelist’s opening presentation.

Jan 1, 2000

By Robert C. Maxton

The foundry industry is a basic source of structural component for all industry. Millions of tons of castings are produced annually in both ferrous and nonferrous alloys. These castings are subjected to a wide variety of heat treatments, finishing techniques, mechanical tests and machining operations. Through all of these steps the quality of the casting is of paramount importance to the end use of the product. The Quality Assurance Program at Minneapolis Electric Steel Castings Company is designed and established to provide a superior product for both original equipment manufacturers and the mining industry.

Jan 1, 1982

By Robert A. Westman

The INRED process has been developed step by step by Boliden since 1972 at MEFOS, the Foundation for Metallurgical Research, at Lulea in Sweden. The demonstration - plant is number five in this series. The purpose of this plant, which has a nominal capacity of 60,000 tonnes per year of hot metal is to: 1) prove the process on a sufficiently large scale to provide the basis for construction of production plants, 2) test various kinds of raw materials on behalf of licensees, 3) train operators of the first production plant, 4) develop the process further for special applications.

Jan 1, 1983