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By James R. Jones

It has been 2-1/2 years since the Congress passed the Surface Mining Control and Reclamation Act of 1977 (PL95-87) the Office of Surface Mining every deadline specified in the Act. Hopefully the Congress will begin to realize that specifying unrealistic deadlines does not accomplish the end desire of legislation any sooner -- it only adds to the confusion, and actually hinders orderly, efficient progress. OSM has been sued by all categories of involved parties -- environmental activitist organizations, the states, and the coal operators. This situation has resulted for two reasons: (1) insufficient time was allotted by the Congress to properly develop the regulations and program, and (2) OSM?s philosophy that it must dictate every detail of reclamation operations from Washington, even though many of its people are inexperienced with coal mining. These law- suits are now demonstrating their value. OSM is showing signs of "pulling-in-its horns" and, hopefully, will approach the revised regulations in a more realistic fasion.

Jan 1, 1980

By J. Boisvert, E. Daniels, C. Deutsch

"INTRODUCTION Conventional mine planning is performed on a single resource model at a selective mining unit (SMU) scale deemed appropriate for the deposit and mining method. Estimation methods such as kriging and inverse distance, commonly used to construct a single model, are susceptible to histogram smoothing (Rossi & Deutsch, 2014). This can be mitigated by limiting the number of composites per estimate, therefore correctly reproducing the distribution of estimates (Boisvert & Deutsch, 2012). Search limiting techniques remedy histogram smoothing at the cost of introducing a problematic conditional bias (Isaaks, 1999) and introduces even greater spatial smoothing. Localization is an alternative, offering histogram reproduction through post processing of more robust probabilistic modeling techniques. A single localized model at the SMU scale is desirable. The correct histogram can be reproduced and a single model allows for the use of conventional mine planning and resource evaluation techniques. Despite the advertized benefits of localization, the necessary reliance on a larger panel scale as a middle step in the localization process yields unsightly “edge-effect” artifacts (Boisvert & Deutsch, 2012). Two approaches to artifact reduction are presented here. The first is a straight forward optimization approach designed to minimize an objective function that penalizes artifacts including panel edge discontinuities to generate a model free of panel edge-effects. The second approach redefines a panel in a less conventional fashion as a randomly chosen set of SMUs throughout the domain. This method produces a model void of any regular panel shape resulting in an artifact free model. Artifact reduction minimizes the obvious “edge-effect” issues of localization but local precision issues described by Boisvert & Deutsch (2012) persist. Localization is not a replacement for quantified uncertainty for comprehensive risk analysis and resource evaluation. LOCALIZATION Initially developed with Uniform Conditioning in mind, localization collapses a distribution of local uncertainty at a panel scale to an SMU scale model for mine planning (Abzalov, 2006). This process has been extended to Indicator Kriging (Hardke, 2011), Sequential Gaussian Simulation (Boisvert & Deutsch, 2012) and MultiGaussian Kriging (Daniels and Deutsch, 2014). The localization process is performed in a similar fashion regardless of which technique is chosen to create the prior model of uncertainty. Methodology There are three scales of importance considered in the localization process. The point scale, otherwise known as the data scale, is the smallest and is the scale at which experimental data is collected. The SMU or block scale is the familiar scale at which mine planning and resource evaluation takes place. Lastly, the panel scale is larger and contains a number of SMUs. Each of the three scales is illustrated in Figure 1."

Jan 1, 2015

By David M. Abbott

This paper is a companion to, and amplification of, the ?History? section of the 2014 version of the SME Guide for Reporting Exploration Results, Mineral Resources, and Mineral Reserves (SME Guide). The need for the careful examination and evaluation of mineral deposits has long been recognized. In the book De Re Metallica, Georgius Agricola noted, ?Moreover, a prudent owner, before he buys shares, ought to go to the mine and carefully examine the nature of the vein, for it is very important that he should be on his guard lest fraudulent sellers of shares should deceive him? (1556, p.29). Agricola further stated, ?Now a miner, before he begins to mine the veins, must consider seven things, namely: the situation, the conditions, the water, the roads, the climate, the right of ownership and the neighbors? (1556, p. 30). The elements of Agricola?s seven things, much expanded, are incorporated into the 2014 SME Guide. As reflected in this quotation, veins were the primary concern of mining until 20th century technology permitted bulk mining techniques. The need for standardization of reserve descriptions arose along with the development of western mining in the United States and the concurrent development of mining engineering and mining geology as professions. By the turn of the century, debate about terminology of various classes of reserves was in full swing. Herbert Hoover noted in 1909 (p. 16-17), ?The old terms ?ore in sight? and ?profit in sight? have been of late years subject to much malediction on the part of engineers because these expressions have been so badly abused by the charlatans of mining in attempts to cover the flights of their imaginations. A large part of Volume I of the Institution of Mining and Metallurgy has been devoted to heaping infamy on these terms, yet not only have they preserved their places in professional nomenclature, but nothing has been found to supersede them. ?Some general term is required in daily practice to cover the available field of visible ore, and if the phrase ?ore in sight? be defined, it will be easier to teach the layman its proper use than to abolish it. In fact, substitutes are becoming as badly abused as the originals ever were. All convincing expressions will be misused by somebody.? Hoover (1909) noted that the common terms at the time were: ? Positive ore or ore developed: Ore exposed on four sides in blocks of a prescribed size. ? Ore blocked out: Ore exposed on three sides within a reasonable distance of each other. ? Probable ore or ore developing: Ore exposed on two sides, ? Possible ore or ore expectant: Ore in whole or in part below or beyond the range of vision. Hoover stated that these, and similar terms, overlapped and had the difficulty of failing to account properly for geologic variation in metal distribution beyond the exposed face. Certainly assuming extension of values along a vein is reasonable, but how far? Also, these definitions are for vein deposits, not all types of deposits are in veins. Hoover (1909, p. 19), therefore, defined the following terms. ? Proved ore: Ore where there is practically no risk in failure of continuity. ? Probable ore: Ore where there is some risk, yet warrantable justification for assumption of continuity. ? Prospective ore: Ore that cannot be included in the above classes, nor definitely known or stated in any terms of tonnage.

Feb 1, 2014

By Karl Ingmarsson

Larger mines spend millions of dollars annually on rock drilling tools, but often purchase based on historic consumption. The results vary from excess inventory to acute tools shortages. These lead to emergency sourcing, sometimes mixing products that don’t perform optimally. Boart Longyear analyzed the usage pattern of 96 thousand drill bits at thirteen different underground mining contracts, showing very high variability. The monthly standard deviation on a product level was 42%, with the highest for development and low volume bits. A new rule of thumb is suggested to carry only one month of safety stock for high volume bits, but increase to three months for low volume bits. This balance will reduce the risk of outages with less inventory. The accuracy can be improved by considering the specific conditions at each mine and reclassifying individual bits for a different safety stock level. Root cause analysis and collaborative forecasting between mines and suppliers can lead to further optimization of availability and inventory levels.

Feb 1, 2024

By D. C. Shumway

Recently, the health of the cement industry has been threatened by the impact of environmental regulations, over-zealous state and federal agencies and radical environmental groups. Unfortunately, cement plant operations tend to trigger every environmental regulation and program promulgated, plus several programs designed specifically for the cement industry. These environmental burdens come at a time when the cement marketplace has been impacted by imports resulting in a situation where it has been difficult to increase prices to offset these increased environmental liabilities. The competitive world market forces the cement industry to seek creative ways to reduce costs. With additional major environmental programs coming down the pipe, like the Federal Clean Air Act Amendments of 1980 and EPA regulation of cement kiln dust, the cement industry has attempted to try innovative supplements to cement manufacturing. The cement industry has found that using waste tires, biosolids and other solid wastes in the cement manufacturing process can reduce costs and plant emissions.

Jan 1, 1996

By C. C. Stewart

Jim Walter Resources, Inc. operates four underground coal mines in Alabama. In 1986, during longwall recovery operations, sparks from a torch ignited methane that migrated onto the face after a roof fall. The fire quickly spread to the gob at the tailgate end of the longwall. The fire was successfully "area" sealed and mining operations resumed after five weeks. However, several problems were encountered during this process. This paper describes the events following the fire, methods used to control the situation, problems encountered, and steps taken to ensure preparedness for any future occurrences of this type.

Jan 1, 1993

By K. J. Stanaway

Environmental pressures on waste disposal are forcing pigment producers to use higher content TiO2 feedstocks with lower levels of trace elements. Despite this, 50% of the worlds TiO2 comes from ilmenite concentrates with only 37 -54 % TiO2 An industry growth rate of 25 % in the next ten years combined with trends to diminishing resources and lower grades for rutile (95 % TiO2) and leucoxenized ilmenite (55 to 90% TiO2) mean that unless new discoveries are made soon, the industry will become even more reliant on ilmenite. A hypothetical ideal feedstock is presented and strategies to obtain it are suggested. Reasons for some of the mineral specifications are given.

Jan 1, 1994

By C. S. Harman, C. A. Enright, J. F. Brune

"The mining environment presents challenging and complex situations for the application of medical care. The combination of remote locations, difficult access and longer response times may create an increase in morbidity and mortality in the event of serious accidents. The U.S Mine Safety and Health Administration (MSHA) has only minimal requirements of first aid training for mine workers. For mine rescue team members, MSHA requires medical training at the Emergency Medical Responder (EMR) level, as only prescribed by mine rescue contest rules. This paper examines, based on mine accident statistical information, whether a higher level of medical training, for example at the Emergency Medical Technician (EMT) or at the Advanced Life Support (ALS) level can better address injuries most commonly disabling or leading to the death of miners in the United States. BACKGROUND Prehospital emergency medical care for the sick and injured has evolved considerably from first inception. Ambulances used to be staffed by persons with little training and equipment and prehospital care was focused largely on the rapid transport of the injured person to a hospital and. The modern prehospital care model was initially developed in military applications, where medics were responsible for some treatment on the battlefield and rapid transport to the care of a physician. In 1965, the National Academy of Sciences and National Research Council Committees on Trauma and Shock published Accidental Death and Disability: The Neglected Disease of Modern Society (National Research Council Committees on Trauma and Shock, 1966). This white paper laid out the consequences of the insufficiency of the Emergency Medical System (EMS) in the United States at that time. According to this paper, in 1965, 107,000 people were killed from accidental injury, with another 400,000 injured with permanent disability. The authors estimated that approximately 50% of ambulance services were provided by local morticians that were not capable of rendering advanced life support. The paper states that, based on experiences in the Vietnam war, seriously wounded soldiers had a better chance of survival in the battle field compared to traffic accident victims with similar traumatic injuries because the military was capable of providing first aid and efficient transportation to emergency care facilities. The white paper states that death rates from battle injuries declined significantly from 8% in World War I to 2% in Vietnam. The publication of this white paper is credited for the broad evolution and rapid advance of the civilian EMS system after 1965. It eventually lead to the creation of the National Highway Transportation Safety Administration (NHTSA) National Standard Curricula (NSC) for emergency medical care in 1985. Training, and therefore required skill and knowledge for prehospital emergency care has continued to grow to reach the current standard."

Jan 1, 2016

By Robert Bissonette, Samir Sbai

Machine Situational Awareness (MSA) requires the ability to efficiently evaluate the probability of interaction of objects within the environment, without creating false alarms or ignoring materializing hazards. To do this, an MSA system needs to assign context to observed object activity and integrate as much information about object identity, kinematics, behavior, and current state as possible. This paper describes how known object characteristics, attributes, and activities (drilling, dumping, driving, etc.) can refine interaction probabilities and help identify rogue actors that introduce anomalous risks to the health and safety of miners. Path projections need to incorporate velocity and direction as a function of time while accounting for terrain, safety response, environmental factors, current assigned activity, etc. This paper also describes the methodology for properly prioritizing responses to place the highest value on human safety.

Feb 1, 2024

By James R. Arnold

Over the past few years several commercial wetting agents and drying aids have been tested in the lab and in the plant at Gold Fields Mining's operations at Mesquite and Ortiz. The major goal was to increase recovery with these surfactants by improving the permeability of the pad and increasing the rate of penetration through the rock.

Jan 1, 1988

By Kevin Fitzpatrick, Carmen Scalise, Patrick Jensen

"The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) owns and operates the Tunnel and Reservoir Plan (TARP) system which was adopted in 1972. TARP is a network of 110 miles of deep tunnels and ultimately 3 large reservoirs to combat waterway pollution and flooding within a 350 square mile area served by combined sewers. The original TARP concept included additional tunnels to convey CSOs from the largest storms to the reservoirs. With the initial TARP tunnels complete and the reservoirs nearing completion, MWRDGC commissioned hydraulic and hydrologic modeling studies to analyze the benefits of additional conveyance tunnels. These updated studies optimized the configuration of additional tunnels considering integration with potential future local sewer system upgrades. The alternatives considered several routes of 25, 30, and 35 foot diameter tunnels, ranging from 10 to 18 miles. Alternatives were analyzed based on projected reductions to basement flooding compared to the relative costs. TUNNEL AND RESERVOIR PLAN After World War II the Chicagoland area underwent rapid growth and development. With the Metropolitan Water Reclamation District of Greater Chicago's (MWRDGC) service area becoming increasingly impervious, the flat Chicago landscape was increasingly at risk of significant flooding. In the mid and late 1950's, Chicago experienced multiple extreme storm events that had significant impacts on the city and generated the momentum necessary to initiate what would ultimately become one of the world's largest civil works undertakings. In 1957 a Flood Control Coordinating Committee was formed, consisting of representatives of the MWRDGC, Illinois Department of Public Works, Cook County, and the city of Chicago, to review various plans and develop recommendations for a course of action. With more than 50 alternative concepts being identified, the Tunnel and Reservoir Plan (TARP), which itself is a composite of various alternatives, was adopted the by the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) in 1972. The need to adopt a long term plan was further influenced by the Clean Water Act, which was enacted only 8 days prior."

Jan 1, 2016

By Richard P. Killmeyer, Carl P. Maronde, W. W. Wen, Peter J. Suardini

Under a cost-shared Department of Energy contract, awarded as part of the Coal Preparation Program&apos;s High Efficiency Preparation subprogram, Custom Coals International will be installing and testing a 227 kglhr micronized-magnetite cycloning circuit in PETC&apos;s Coal Preparation Process Research Facility. The project includes the design, construction, testing, and decommissioning of a fully integrated circuit complete with feed coal classification to remove the minus-30-micron material, dense-medium cycloning of the 300 by 30 micron feed coal using micronized magnetite (<10 microns), and medium recovery via drain & rinse screening and various stages and types of magnetic separation. This paper will describe the micronized-magnetite beneficiation technology and the scope of work for this project including an update on the status of the project, the circuit, and the proposed test plan.

Jan 1, 1995

By J. Luo

A major design problem for upper seam longwall gate roads that are to be constructed in a multi-seam environment is to predict the effects of stress field changes created by interaction. To quantify these effects, case study data were analyzed to develop empirical stress transfer relationships between seams for both longwall and room and pillar mining. Data analysis showed vertical movement and roof characterization in the upper seam to be controlling factors in damage prediction and, therefore, gate road planning and design. CMRR (Coal Mine Roof Rating) was correlated with the multi-seam roof characterization systems previously used. A WINDOWS-based software package named UGLY (Upperseam Gateroad Longwall Stability) was developed. Results from selected case studies were correlated with upper seam stress predictions.

Jan 1, 1997

By Jurgen Hahn

The paper reports on both, the design and decision making for the filters in a backfill plant in Europe as well as more then 10 years of operation and maintenance experience of the vacuum disc filters installed. It begins with the first step, the filter sizing based on a sample provided by the customer, followed by the commissioning of the filter units and reports on the development of the filter performance during the following 10 years of operation. Based on the physical properties of the sample and the process targets of the client for the backfill plant, the paper shows the logic steps taken in the laboratory to ensure the target moisture, determine the required filtration area and filter size as well as the selection of the ancillary units and the formulation of the performance guarantee. The paper discusses some issues with filter operation during the commissioning phase and the actions taken. Finally, the paper concludes by highlighting the gradual change over the more than 10 years of operation and how this change affected filter performance and operating costs.

Feb 1, 2024

By Anna Sieminska-Lewandowska, Monika Mitew-Czajewska

"The construction of 6.3 km long central part of 2nd metro line in Warsaw was completed in September 2014 (7 stations - out of which three 25m deep stations - built using cut and cover method; two single-track tunnels constructed using four EPB TBMs as well as a short NATM section with soil freezing below the existing road tunnel). Central section of the 2nd metro line was opened to public after verification and testing in March 2015. Design and build tender for the extension of this line in East (three stations) and West direction (three stations) was announced with total length of running tunnels – approx. 5 km. Detailed description of a very complex geotechnical context, different construction methods, challenges encountered and solved during construction and finally lessons learnt on this interesting project are presented in the paper. DESCRITPTION OF THE PROJECT Introduction The very first concept plan of the metro system in Warsaw was designed several years after regaining independence by Poland in 1918. In 1929, following the geotechnical survey, design works begun, but the economic crisis of the 1930s stopped it. After a few years of break, in 1938 a coherent concept of the metro network was proposed to be implemented in phases over the next 35 years. In total, construction of 46 kilometers of metro, including 31 km of tunnels and 15 km on surface, was planned. Unfortunately, World War 2 made the implementation of those plans impossible. In the post-war period several metro designs were elaborated, but none except one was scheduled for implementation. Construction of the 1st, 23.1 km long, North-South line commenced in 1983 and finished in 2008 (Sieminska-Lewandowska et all. 2009). Nowadays, Warsaw covers the area of 517 km2 and, according to year 2014 statistical data, the city has much more than 1.7 million inhabitants. Only one operating metro line is not sufficient for such a populated city. Up-to-date metro plan, shown on Figure 1, includes also 30.5 km long 2nd metro line. It’s route is divided into four sections: Western Section with the length of approx. 9.2 km and 9 stations, Central Section with the length of 6.3 km and 7 stations, North-East Section with the length of 7.7 km and 6 stations, South-East Section with the length of 7.1 km and 6 stations. The construction of the central part of the 2nd metro line in Warsaw was completed in September 2014 and its operation started in March 2015. The paper focuses on challenges encountered and solved and lessons learnt during construction of the central part of the 2nd metro line in Warsaw."

Jan 1, 2016

By D. Yeager

Researchers at the U.S. Bureau of Mines have successfully used a genetic algorithm to tune computer models of three column flotation units simulating a separation circuit. The computer models rely on empirical constants that are selected so that the models accurately predict the performance characteristics of individual column flotation units. Unfortunately, these empirical constants have traditionally been selected using a time consuming trial and error process. A new and more efficient approach to selecting empirical constants for computer models has been developed. A genetic algorithm has been used to select the empirical constants for column flotation models used to simulate a three column circuit. Genetic algorithms are search algorithms based on the mechanics of natural genetics. They rapidly locate near optimum solutions in difficult search spaces. Bureau researchers have used these innovative search algorithms to dramatically reduce the time needed to select empirical constants for column flotation models. The approach is applicable to the selection of empirical constants for numerous other computer models.

Jan 1, 1995

By Jr. Pickering

Commercial quality kaolin deposits occur in fluvial sediments in both central-eastern Georgia and in the eastern Amazon River area of Brazil. Distinctive coarse and fine particle size kaolin deposits are present in both areas; they have many remarkable similarities for mineral deposits occurring at such wide geographic separation. Industrial, mineralogical, crystalline, and chemical resemblance of the coarse and fine kaolin deposits from the two areas will be described in detail. Knowledge of similarities of the Brazilian clays to those which have dominated world production in Georgia will help to develop superior quality kaolin products for world use in paper, paint, plastic, ceramic, and other applications.

Jan 1, 1997

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"There are three distinct producing iron ranges in Minnesota, the Vermilion, Mesabi and Cuyuna. In trend the Vermilion and Mesabi are approximately parallel (E.N.E. and W.S.W.) and about fifteen to twenty miles apart. The Vermilion lies farthest north, near the. Canadian boundary. It is from seventy-five to eighty miles due north of Duluth. The length of its productive part is about twenty miles.The Mesabi Range is from fifty to seventy-five miles north and northwest of Duluth. Its length along the strike is about 110 miles, and the length of its present productive area about eighty miles. The Cuyuna range lies southwest of Duluth nearly ninety miles, and is the last of the Lake Superior iron ranges to be developed. The relative positions of the ranges are shown on an accompanying map. The Mesabi Range is by far the largest producer and contains the largest ore reserves of the three. The Cuyuna is next in quantity of proven ore, and in production since 1916, while the Vermilion is first in average quality of ore.On the west, both Vermilion and Mesabi ranges disappear beneath heavy glacial drift; and on the east, extend into Canada, the so-called Gunflint range near the international boundary being an eastward continuation of the Mesabi formation. This latter range is of no economic importance, however, at present. The exploration and development of the Cuyuna range has proved up a considerable tonnage of manganiferous iron ore, besides ordinary merchantable iron ore."

Jan 1, 1920

By William Gleason

"Mining roots run deep in Glenrock, WY, a town that was founded in part, because of the coal mining that began in the late 1800s. But that rich history also now threatens large parts of the town that were built over the top of the mines. Like many towns in the Western United States, mining is a proud part of the historical fabric and heritage of the town, but the legacy issues from past mining activities continue to present challenges to modern-day engineers.In the case of Glenrock, a small town about 40 km (25 miles) east of Casper, it is flooding from a century of water that has accumulated in the down geologic dip of the furthest northeastern extent of 87 ha (217 acres) of mine workings that has made the town susceptible to sinkholes and other issues (Fig. 1).Full commercial coal mining production began in Glenrock in 1887 during the development of the Fremont, Elkhorn and Missouri Valley railway. Due to poor overlying roof rock and continuous flooding within Glenrock, Mines No. 1 and 2 were fully closed in 1909. During its history, an estimated 87 ha (217 acres) were mined with 50 to 60 percent extraction ratio within the eastern town limits through room-and-pillar mining. It is estimated that the mines produced 22 kt/a (25,000 stpy) during their lifetime. A century later, the water pressure built up in the northeastern most portion of the mine has created serious concerns for residents.In 2016, the Wyoming Department of Environmental Quality’s Abandoned Mine Lands Divisions (AML) investigated a number of subsidence events in the town including sinkholes following heavy precipitation. The AML investigations confirmed that most events were related to the previous mining in the area.Mitigation efforts on the mines were done in the 1980s and 1990s, but the problems in the town and in a nearby subdivision persisted, leading the AML to search for alternative solutions."

Nov 1, 2019

By NARAYAN K. BHAGAT, ARVIND K. MISHRA, Aditya Rana, M. M. Singh

The paper presents an innovative directional controlled blasting (DCB) technique for excavating unstable slopes along the Konkan railway in India without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw were developed. A unique sequence of firing and excavation with powder factor varying between 0.04 and 0.39 kg/m3, irrespective of the actual free face, was used for rock blasting. The process controlled the throw of blasted material over the track and resulted in a smooth and stable wall. The slope angle was changed from 80–82 to 45–47 degrees, and possible wedge, planar and toppling failures were eliminated. No incident of rockfall and slope failure along these slopes has been observed after the stabilization.