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By William Gleason

"In a time that seems to be dominated with nothing but bad news coming from the mining industry, there is a success story that has been quietly happening in Southwestern Wyoming for more than 60 years, and it is one that is likely to continue for many decades to come.Beneath the wind swept high desert plains of Sweetwater County, WY, about 32 km (20 miles) west of Green River, lies the Green River Basin where five companies, including Tata Chemicals North America (TCNA), are mining the world’s largest known deposit of trona and, in turn, are collectively producing 15.3 Mt/a (17 million stpy) of soda ash.“We have a long-term growth story that has been, and will continue to be a steady earner for many years to come,” said J. Martin Keighley, managing director of TCNA who has been in charge of the mine, formerly known as General Chemical Industrial Products Inc., for Tata Chemicals for about three years.According to the U.S. Bureau of Land Management (BLM), Keighley is safe with his prediction of future success. The BLM estimates that there are enough reserves in the Green River Basin to last another 2,000 years. Currently, four trona beds in the Green River Basin are being mined and in all, there are 25 major trona beds that occur within the Wilkins Peak Member of the Upper Eocene Age Green River Formation. The trona deposit as a whole covers about 2,500 km2 (1,000 sq miles) within the Green River Basin.And imagine, this economic mainstay in the region was discovered accidently.Prior to 1948, soda ash, the salable commodity that comes from trona and is used in a host of products including glass and detergent, was produced synthetically. In 1938, an oil and gas exploration team working in the Green River Basin came away with a find that would change the soda ash industry and the physical and employment landscape of southwestern Wyoming forever. Within 10 years, the communities of Green River and Rock Springs, which were built largely on the back of coal mining and railroads, had another commodity beneath their feet."

Jul 1, 2016

By Chee Theng

"Mining professionals are a resilient lot. Sure, copper prices are dismal, permitting processes seem interminable and the top mining companies are shedding jobs like a Shetland sheepdog sheds hair. All the more reason to hone technical skills, reconnect with old contacts and get one’s finger on the pulse of the industry.More than 400 did just that in the balmy sunshine and among the saguaro cactus of the Tucson venue of the SME Arizona Conference.Giving the keynote speech was Patrick Merrin, vice president at Hudbay Minerals (see box), while the luncheon speaker was University Distinguished Professor Mary Poulton, director of the Lowell Institute for Mineral Resources at The University of Arizona.“Attendance was great, especially given the copper price,” said Ta Li, vice president of business development at Tetra Tech and 2001 SME President. “The luncheon speaker was one of the better ones in recent years. Her talk contained a lot of fresh ideas, and practical versus theoretical concepts.”Talk about values, not economicsPraise was unanimous for Poulton, who gave a thought-provoking talk on “The New Face of Mining: The Culture Change for Compatible Mining.” Corporate social responsibility has been embraced by the metals mining industry, and it’s being done right, she said. “So why do we have more conflict? Why are there more protests? Why does permitting take longer and longer?” Poulton made a case for an approach based on compatible, rather than sustainable, mining to present a new face of mining that can be compatible with communities, cultures and the environment, and still be profitable. When the mining industry starts to talk about compatibility between what it is doing and what “me,” as the consumer, wants, what “we,” as citizens of a community, want, and what’s good for the “world,” we’re going to see the next culture change happen, she concluded."

Jan 1, 2015

By John F. Oyler

The performance of high alumina refractory subjected to high compressive loads and high temperatures is an area in which operating experience is quite limited. This paper documents the results of five months of operation of a combustion chamber lined with 83 pct alumina brick subjected to compressive stresses as high as 45psi and hot face temperatures of about 2750°F. It also describes a method for predicting long term subsidence results based on the limited information available in standard hot load limit tests. Descriptions of the chamber itself and the pilot plant upon which its design was based are included.

Jan 1, 1978

By Yung Sam Kim

The study of ultrasonic-wave propagation in substances has been remarkably advanced in recent years in most engineering and science fields. The main object in studying the velocity of ultrasonic-wave propagation in solids, is to determine dynamic properties of these materials. The present paper, however, presents some other possible applications of ultrasonic-wave propagation in the study of rock mechanics as follows: Investigation of the mechanism of microseismic activites of geologic materials, (a) at initial or low stress level, (b) at final or fracture stress level, and (c) under fatigue loading condition. Also, correlations among stress level, density, and the velocity of ultrasonic-wave propagation in rocks are discussed in this paper.

Jan 1, 1973

By A. H. Sharbaugh

It is believed that considerable economic benefit would arise if run of mine (ROM) coal from the underground mines in the Winifrede seam could he enriched before shipment to the preparation plant by partial removal of the shale. Shale could comprise up to 50% of the ROM product. Complete mine-mouth separation is not necessary, but any process must be dry and have high Btu recovery. We have conducted a preliminary analysis of coal/shale mixtures from the Winifrede seam and we find that it is quite possible that a 50-50 ROM mixture of coal and shale could be converted to a 60-40 coal-shale mixture by inspection of individual lumps coming from the mine. The device would consist of a feeder/siever section to deliver the ROM coal > 5 cm (2 in) to an inspection station via a conveyor belt. This inspection station decides if a piece is coal or shale, and if it is shale, activates an air jet to blow shale off of the belt. We have evaluated a dielectric loss technique for the inspection device. The potential advantages of the dielectric loss method are high throughput, low capital cost, and no special handling or licenses would be required. Such a single lump inspection technique is made possible because of advances in high speed electronics and servo systems. This paper provides a summary of our analyses on the Winifrede coal sample, a description of a proposed apparatus to separate coal from shale, some of the experiments needed to demonstrate our ideas.

Jan 1, 1984

By H. Mischo, F. Daniela, L. Schaarschmidt, I. Paschke

In order to safely store radioactive waste long-term, HAW repositories in saliferous formations have to be backfilled. The main purpose of those backfill operations is the restoration of the geological barrier function of the containment area. For best possible results the used material should be of a comparable composition or characteristic for the host rock formation. Additionally, the material should show a high density after completion of the backfilling process as well as a low permeability. A major aspect to consider in these processes is the minimization of the gap of the backfill body to the roof of the drift. To fulfil those requirements, a micro-structure stabilized crushed salt backfill material has been developed as part of the GESAV-I-project. Due to the material composition of this so-called GESAV-material, salt mineralcrystallization processes start after emplacing it, a process that leads to the polyhalite formation. With the crystallization of polyhalit, the halite grains are bridged, which in return stabilizes the matrix of the backfill. The GESAV-II-project continued successfully what GESAV-I started and determined an ideal backfill method in order to build the backfill bodies composed of GESAV-material. Due to the compaction of the material during emplacement by vibration, high in-situ densities, low permeabilities and a backfill factor close to 1 was able to be reached. In the following SAVER project this journey of practical test underground will be continued.

Mar 2, 2022

By C. Guria

A modeling, simulation and optimization study of a complex industrial fluorspar beneficiation plant (Kadipani, Gujarat, India) with fourteen/ten flotation banks is carried out to find an optimum/near-optimum circuit for the given quality of feed ore. The phenomenological flotation model developed by Mehrotra and Kapur (1974) is used for circuit optimization. Two different optimization problems are formulated and solved. The first optimization problem involves a single objective function, which uses available plant data to estimate the feed-characterizing parameters, i.e., the flotation rate constants, by minimizing the weighted sum-of-square errors between the computed and plant values. The second optimization problem involves two objective functions to obtain several simplified circuits. The number of non-linking streams and the overall recovery of the concentrate, i.e., the acid-grade product, are maximized simultaneously in this problem. The single-objective variant (SGA-II-mJG) of the binary-coded elitist non-dominated sorting genetic algorithm with the jumping gene adaptation, NSGA-II-mJG, is used for the first problem, while NAGA-II-mJG (Guria et al., 2005 a) is used for the second problem. Simplified circuits with a few split streams are proposed on the basis of the present optimization study, which enhance the recovery of the acid-grade product without affecting its quality, for a given total volume of the flotation cell-bank. Even though the optimal solutions have certain drawbacks, they suggest a meaningful direction in using an iterative fitting of parameters to such optimal circuits, followed by re-optimization. Key words: Froth flotation, Mineral processing, Industrial fluorspar beneficiation, Feed identification, Circuit/network optimization, Global optimal, Jumping gene, Genetic algorithm, Multi-objective optimization

Jan 1, 2009

By Rick Frechette, Greg Nelson

"The 2018 Elko Roundtable was held at the Red Lion in Elko, NV on March 15, 2018. The gracious host was once again Knight Piésold. Attendance was robust with representatives from more than 14 mining properties across Nevada representing nine corporations. Total attendance was at its highest in almost a decade. A high level of interest was also gauged by the number of companies with multiple attendees.The topic of water in mining was clearly a factor in creating the large show of interest. In terms of industry trends that are tracked annually, this topic had been absent from the list for more than 10 years (Deloitte, 2018) but was squarely planted there this year. And deservedly so. Three attending companies are signatories of the International Council on Mining and Metals (ICMM) which espouses a firm stance on water stewardship (ICMM, 2017).How’s the water?It is reported that water scarcity affects more than 40 percent of the world’s population (Deloitte, 2018). Consumption of water in the United States, based on the last detailed census, entails only 1.5 percent usage by the mining industry. The largest users are reportedly thermoelectric power and irrigation, combining for more than 75 percent of the U.S. consumption. During the prior census period, water usage at mines was up dramatically (USGS, 2014).Mine water source usage is primarily a mix of ground water and saline or fresh surface water resources. Over the previous period, saline sources experienced the greatest percentage in growth as a mine water source, nearly doubling in use. Nevada ranks second as a state nationally in mine water consumption. California is the leader, and Nevada is immediately followed by Utah and Alaska (USGS, 2014).Water rights in Nevada and the ongoing litigation at the state level, particularly over the Humboldt River basin, have elevated the concern over the supply of water and have raised the interest regarding the topic of water across the mining industry as well as within other industries.The Elko Roundtable meeting began with a safety share and introductions, and included each attendee mentioned a water problem or solution that he or she would like to discuss during the day. An interesting list of subtopics was developed from this round robin and yielded the following most common themes:• Mine pit dewatering during operation and pit wall stability.• Draindown from tailings dams and heap leach pads and dealing with this at closure.• Post closure pit lakes, pit lake water quality and associated water rights."

Dec 1, 2018

By Paul D. Tomlingson

The difficult and often harsh working environment of the mining industry can stress both personnel and equipment to the extreme. Often, the unintended consequences of this environment lead to confrontations between departments, as each goes about its tasks of mining, maintaining or supporting these activities. On occasion, the confrontations may result in criticism of other departments for perceived or real sins or omissions. The offended department may not be able to change the circumstances, but can only complain while frustration persists. The most effective solutions are the actions of the mine manager. By establishing mutually supporting roles of each department and specifying conditions for the interactive conduct of maintenance, the mine manager can better assure that the inherent problems of the mining environment are neutralized.

Jan 1, 2011

By D. L. McCain

In considering slurry transportation for Consolidation Coal Company's Loveridge Mine in Northern West Virginia, many things were taken into account. The advantages of slurry transportation in comparison to shuttle car, belt and rail transport have been given in previous publications." These include increased safety and the potential for increased productivity. In addition to these considerations, the slurry transport system installed in an existing mine provides an alternate or additional transportation mode to the one already existing. In the Loveridge Mine, this is rail haulage. Since the rail system is a single track system and the distances involved are several kilometers, it is not always possible to provide for haulage of loaded cars, return of empties, supplies and maintenance in an efficient manner. Slurry transport of the coal from the production faces to the preparation plant allows the rail system to fulfill the remaining transportation needs in an efficient manner. Consol initiated development work in slurry transportation in the early fifties leading to the construction and operation of the 174-km (108-mile) Cadiz-to-Cleveland pipeline which carried 1,200,000 metric t/y (1,300,000 t/y) from 1957 to 1963. Development work on coarse coal slurry transportation for underground mines started in 1970 with feasibility tests on coarse coal at Conoco's Ponca City, Oklahoma, slurry test facility. A series of tests were conducted in several locations as development work proceeded on the various subsystems, mechanical equipment and controls required to produce a working system to follow a continuous miner in a room-and-pillar type mine, then to combine the coal production from several mine faces for mainline transportation to the preparation plant. The face system, including the crusher-pump vehicle, hose hauler vehicle, slurry booster pump units, return water unit and 900 to 1,200 m (3,000 to 4,000 feet) of pipeline was brought together for the first time and tested as a system at Consol's Robinson Run Mine in northern West Virginia in 1975. A pipeline wear test at the Loveridge Mine where 300,000 tonnes (330,000 tons) of minus 127-mm (5-inch) run-of-mine coal were pumped from the raw coal bin into the preparation plant and a large scale test in Ponca City on a multiple feed sump where several slurry flows could be combined to provide surge capacity and a constant reclaim rate for mainline transportation completed the preliminary testing for a complete system. A decision was made to commit the system to a mine, and the south half of the Loveridge Mine was chosen. This site required the transporting of coal from one longwall and two continuous miner development faces. To prevent startup and unexpected problems in the slurry system from shutting down production of coal from the longwall face, the rail car loading point from the main section belt was chosen as the feed point for the slurry system and the design would allow for rapidly switching from one transport mode to the other. Scheduling of required development entry work and the developmental nature of the system led to a decision to install only one continuous miner face slurry transport system rather than two for this first system. The type of continuous miner in use at the mine for the foreseeable future was the Joy 2BT6 twin boring machine. This machine cuts a stable, arch-shaped entry and was therefore allowed to mine about 26 m (85 feet) of entry before roof bolting was re¬quired. Since peak production from this type of machine was not high, a smaller transport system could be used with it.

Jan 1, 1981

By A. M. Marabini

Flotation of rutile with N-benzoyl-N-phenyl-hydroxylamine (N-BPHA) has been investigated. Initially, floatability tests were performed in a Hallimond tube. The results indicated that rutile was floatable in the pH range from 2 to 4 at N-BPHA concentration between 2x10-3 M and 2x10-2 M. Selectivity against hematite was recognized when operating at pH values below 2. Following the hypothesis of the formation of a surface chelate between N-BPHA and titanium ion, this compound was precipitated from a solution of Ti(SO4) to which N-BPHA was added. I.R. spectrometry oft the rutile before and after treatment with N-BPHA solution confirmed the presence on the rutile surface of the same compound. The absorption isotherm and kinetics were determined by analyzing N-BPHA in solution with an U.V. technique. A hypothesis for the mechanism of adsorption of N-BPHA on rutile is suggested.

Jan 1, 1982

By G. Purcell

When coal in an oil/water slurry is ground to minus-200-mesh in a ball mill, some of the mill energy, normally wasted as heat, can be usefully recovered to help emulsify the oil. If the discharge flows onto a suitable sized trommel screen, water and ash material are rejected through the screen while coal and oil ball together to give a clean coal product. A small (6-lb/hr) continuous plant has demonstrated the feasibility and the limitations of this process for New Mexico coals.

Jan 1, 1980

By M. S. Celik

Unlike most other minerals, electrokinetic measurements of calcium montmodonite (a clay mineral) and u1exite (a boron mineral) exhibit an unusual behavior. While the addition of monovalent salts such as NaCI and KCI is expected to compress the electrical double layer with a resultant less absolute charge, an opposite trend is observed. A set of systematic experiments with monovalent and multivalent ions has been carried out to understand the mechanism of this phenomenon Examination of the results reveals that the behavior of montmorillonite is dictated by the exchangeable divalent cations at the edges which undergo an exchange process with monovalent cations resulting in the reduction of positive charges. The solubility of ulexite, on the other hand, is found to decrease with increasing monovalent cation concentration leading to again an increase in the absolute negative charge.

Jan 1, 1996

By R. H. Ring

The Automatic Extraction System (AES) was designed and built under a U.S. Department of Energy Contract by the National Mine Service Company in cooperation with the Lee Engineering Division of Consolidation Coal Company. The Pennsylvania State University, Mining Engineering Section, was contracted as an independent auditor of the AES performance. The AES had a rotating cutter drum like a continuous mining machine; but two hydraulically powered roof supports, four roof-bolting drills, a dust scrubber, a ventilation fan and ducting in the roof supports, semi-automatic control, an extensible chain conveyor, and other innovations led to the distinction "extraction system" as opposed to "miner-bolter" or "continuous mining" machine. After design and assembly, the AES was field tested experimentally in an underground coal mine. The in-mine performance audit was preceded by a computer simulation of the potential production for a later comparison with the actual tonnage mined by the AES. This paper describes the results of an in-mine trial and assesses the production potential of the AES.

Jan 1, 1980

By Anthony M. Bauer

It is the nature of mining to reshape the landscape. Mining is an earth moving process with many of the same activities associated with the regrading of a site for a shopping center, drainage channel, housing project or ballfield. The difference exists only in purpose and duration of activity. The purpose of mining is to, produce a valuable product. The purpose of regrading for construction of a project is to create a predetermined landscape for a specific end use. In both situations the objective is to move earth materials as efficiently as possible. The question is then raised, if similarities exist, can mining operations be directed to shape predetermined landscapes as an integral part of its earth moving activity. This paper will explore the opportunities and issues of shaping sand, gravel and hardrock construction aggregate sites for productive end uses. It is based upon the premise that, as an earth moving operation, the process of extracting sand and gravel includes an inherent capability to shape productive lands as an integral part of the mining operation. In the course of any mining operation non-commercial materials, including overburden, fines and excess sand are handled to extract and process the commercial products. This activity exists regardless of whether or not there is a plan to reclaim the land. Moving this dirt is a basic operational cost. This cost need not be significantly increased when the material is deposited to shape land rather than be stock- piled just to clear the way for mining the deposit. Moving of dirt to create useable land can be guided by the same criteria used to remove the dirt from the deposit: for example, limiting the- hauling distance. Over a period of time earth handling costs can be reduced by minimizing the need to transport the stockpiled material a second time to the new landform location.

Jan 1, 1984

By Richard Snyder

Secretariat of the Coal Mining and Mining Executive Committees' of the National Safety Council (NSC) and Manager of the memberships to both Mining Sections; Senior Consulting Safety Engineer, NSC; member of several committees for consensus Standards of the American National Standards Institute (ANSI); a Certified Safety Professional (CSP) of the Board of Certified Safety Professionals of the Americas, Inc. and a chief proctor for CSP testing and certification procedures, et al. It appears that the tunneling trade is merging into its own renaissance for the decade of the 1970s', and most likely on past the year 2001. Federal interest in underground excavation, and more specifically, rapid excavation expertise has been on the upswing since the latter part of the 1960's, mainly due to the pressing national needs for more raw materials based on the rise for material goods and the projective gloom of possible power shortages. On the pure tunneling side the national needs encompass, in the mainstream of priorities, rapid transportation and water supply excavation as the two top contenders. For instance, the estimates for tunnel mileage for the period 1968-1975 are:(1) Subways---85 miles Urban Highways--- 123 miles Intercity Highways---210 miles Water Supply Routes---528 miles at a total of 946 miles of tunnels. The estimated cumulative underground excavation demand in dollar amounts for the period 1970-1989 are:(1) Construction Oriented Demand--- $35 billions Mining Oriented Demand---$34 billions (which includes the coal-oriented demand on the order of 26 billions.

Jan 1, 1997

By Tom B. Corry

INTRODUCTION Located approximately 48 km (30 miles) south of Dallas, Texas, use to be the site of the Superconducting Super Collider. For those of you unfamiliar with the project, this was a multi-billion dollar project taken on by the U.S. Government for the further advancement of technology, medicine, and science. Major components of the project consisted of a Linear Accelerator known as the LINAC; three accelerating rings known as the Low Energy Boosters (LEB), Medium Energy Booster (MEB) and the High Energy Booster (HEB); the East and West Campuses where the Inner Reactor Halls would have been located; and the 87 km (54 mile) main collider tunnel. Unfortunately, this all came to an end on December 6, 1993, with the termination of the project due to the Government's cancellation of funds. This paper will deal with the two of the underground contracts before the termination. These two contracts were the 1122 contract which ran from N25 to N40 and the 1130 contract which ran from N40 to N55. (See figure 1) The 1122 contract was awarded to us in July of 1992 and consisted of the excavation and support of six (6) shaft varying in diameter from 5.5 m (18 feet) to 8 m (26 feet) and ranging from 39.6 m (130 feet) to 61 m (200 feet) deep and the driving of approximately 13,100 m (.43,000 If.) of main collider tunnel. Our second contract, the 1130, was almost identical to our first

Jan 1, 1995

By N. C. Miller

In situ stope leaching is an innovative mining system that reduces the surface impacts of conventional underground mining. As in any leaching operation, stope leaching requires hydrologic site characterization and control of leaching solutions. Several tracer tests, using sodium chloride (NaCl) in various concentrations, were conducted by the U. S. Bureau of Mines (USBM) in an underground experimental stope to simulate a leaching environment. The tests were conducted in fractured crystalline rock that was partially saturated. As tests progressed, the surrounding fractures became more saturated. A predominant flow direction away from the stope was found during testing. Testing procedures, preliminary results, and remediation ideas based on field observations are presented in this paper.

Jan 1, 1995

By Leland E. Paulson

The Grand Forks Energy Research Center and Commonwealth Edison of Chicago jointly conducted tests in which 400 tons each of subbituminous coal and lignite were dried in a commercial scale dryer, oil sprayed and cooled, then shipped in open-top rail cars from Pekin, IL to Grand Forks, ND and stockpiled. Cars containing raw coal and dried coal that had not been oil sprayed were also transported for comparative purposes. The tests were conducted in August and November of 1974. The subbituminous coal was dried from 26 to 16 pct moisture and the heating value was upgraded from 8,420 to 9,650 Btu/lb. The lignite was dried from 39 to 22 pct moisture and its heating value was increased from 6,420 to 8,300 Btu/lb. Before loading subbituminous coal was cooled to 115° F and sprayed with oil at a rate of from 2 to 6 gal/ton. Similarly, lignite was cooled to 85° F and oil sprayed at rates of from 1 to 2 gal/ton. Both shipments arrived in Grand Forks with a minimum of difficulty. The subbituminous coal was subjected to 2 inches of rain during transit with no change in average moisture content. The cars containing dried and oil treated coal had less material lost to wind than either cars containing raw or untreated dried coal. With both dried lignite and subbitnminous shipments, a moderate increase in temperature was measured during transit. With the subbituminous shipments, ignition occurred near poorly fitted bottom dump doors, but was limited to a very small area. The dried lignite was shipped when ambient temperatures were below freezing, and frozen coal was noted around the edge of the car. At Grand Forks, the coal was stockpiled using proven techniques and has remained stable to this date.

Jan 1, 1975

By Nord L. Gale

Lead, zinc, copper, silver, cadmium and many other heavy metals which are potentially hazardous if released into the environment in wastewater discharges have been of considerable concern to governmental agencies, industry and the general public. In response to this concern, an interdisciplinary research team at the University of Missouri has been funded by the National Science Foundation-RANN program to study trace contaminants associated with the production of lead for the past eight years. Seven modern mines in close proximity to two lead smelters in the forested Ozarks of Southeast Missouri are the largest source of lead in the world and in 1976 alone produced 504,095 short tons of lead, 82% of the United States total production. This new and rapid industrial development in a sparsely populated. rural forest region has offered a unique opportunity for studying the impact of trace metals and for developing improved techniques to control detrimental effects. Research on the wastewater discharges and two methods of biological and recycle control are discussed in this paper. Although the two mine-mill complexes investigated in this study have many similarities, the differences between the two are substantive and warrant separate examination.

Jan 1, 1977