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By Amy McBrayer, Andrea Brickey

The paper discusses the mine planning methods used in the Powder River Basin (PRB), highlighting the differences from open-pit metal mines. It emphasizes the need for agile mine operations due to changing commodity markets and the challenges faced by the coal industry, such as volatile prices and reduced engineering manpower. The study includes a survey of mine engineers to document current practices and identify potential improvements.

Sep 1, 2023

By H. Colijn

The trend in the coal industry for many years has been to make everything "bigger and faster" This also held true for loading and storage facilities. Where once a million ton per year mine was rare, three to five million ton per year mines are not uncommon today in the bituminous industry. This greatly increased production, made possible through mechanization, required greatly improved loading facilities just to get the coal away from the mine. Also, there is a trend toward combining production from more than one mine and cleaning it in a single preparation plant. In addition to increased loading capacity, this frequently necessitates raw coal storage and blending facilities. The development of the unit train, more than any other factor, has contributed to the widespread construction of storage and high-speed loading facilities for clean coal. In the export market, the construction of ever larger coal bulk carriers has contributed to a need for faster and larger loading facilities at ports. The present engineering and construction cost of these larger facilities make it essential that the flow and handling properties of the particular coals are fully known. These properties can be measured well in advance and the proper design criteria established. This eliminates costly surprises later on during start-up and operations. This paper will review coal and coal refuse properties, such as shear strength, cohesion, friability, and the flowability of coal and how they affect the design criteria of storage silos.

Jan 1, 1979

By F. A. Baczek

The Electroslurry TM electrowinning concept has been incorporated into a process flowsheet for recovering copper from smelter flue dusts. The process has averaged 96% recovery of the copper as high-grade electrowon while at the same time removing a majority of the impurities that degrade drawn copper as a result of recycling flue dust and liberator cathodes: The dust is processed through several stages consisting of leaching, copper precipitation, Electroslurry TM electrowinning and waste liquor treatment. The process may be integrated into a smelter operation and become an effective and feasible means of maintaining good product purity.

Jan 1, 1980

By F. L. Jackson

The large scale transportation and storage of sulphur in the liquid state is a relatively new development, but is really only a logical extension of old mining and processing techniques, It is not known who the first person was to win a relatively pure sulphur from ore by melting, but this method was commercially used at least two hundred years ago in Sicily and is still in use today. The Frasch process of mining was invented over sixty years ago, and the development and improvement of-liquid sulphur pumping and handling techniques has paralleled the growth in the Frasch mining industry. During the last fifty years, improvements in the technology of using sulphur have included the premelting of sulphur prior to its being burned for acid production or conversion into CS2 and other compounds. Yet, until fairly recent times, sulphur produced as liquid has been solidified into large blocks at the producing point, broken down by blasting or with mechanical equipment, and shipped in bulk form as a solid.

Jan 1, 1962

By Dennis S. Kostick

Soda ash is produced in over 39 countries by the Solvay ammonia-soda process or by mining natural sodium carbonate deposits. The total production of soda ash in 1980 is estimated at slightly over 29 million metric tons. Synthetic production accounted for over 75% of this amount with the balance of production originating from natural sources (either trona or sodium carbonate-rich brines) found primarily in the United States, Mexico, Kenya, and Chad.

Jan 1, 1981

By James M. Stauffer

There are many types of filters designed to separate a solid from a liquid, including plate and frame presses, pressure leaf filters, gravity filters and vacuum filters. This discussion will be limited to continuous vacuum filtration and, specifically, to continuous rotary vacuum disc filters, drum filters and horizontal belt filters. The use of vacuum filtration can be advantageous in that: 1. The feed slurry can be delivered to the filter either by gravity or by a simple, inexpensive low pressure pump that only has to overcome the resistance of the feed piping system. 2. The filter equipment does not have to withstand high pressures. Consequently, a wide range of materials of construction, including plastic and fiberglas reinforced polyester (FRP), can be used in the fabrication. 3. After the form time, the filter cake is exposed to the atmosphere and the cake is accessible for further operations such as mechanical or physical dewatering, washing, and sampling on a continuous basis. 4. The discharge of the dewatered solids is continuous for directly feeding to the next operation; for example, a dryer. 5. Various methods of discharge can be fitted to the filter to effect optimum discharge of the dewatered cake solids. The principal of operation of a vacuum filter, regardless of type, is basically the same. The filter incorporates a filter medium supported on a drainage system and arranged so that the mixture to be separated (feed slurry) can be introduced to one side of the filter medium on which the solids are trapped and through which the liquid (filtrate) flows due to the applied vacuum.

Jan 1, 1979

By Edward F. Nagle

Instrumentation engineers have recently devised practical methods of metering the net solids flowing in a hydraulic mixture. The solids flow rate is determined by measuring the specific gravity and the flow rate of the mixture. T e specific gravity is measured by a variation of the bubbler system. The flow measurement is made by a somewhat unorthodox orifice requiring field calibrations. The linear mixture flow signal is then multiplied by the specific gravity signal, which is directly proportional to the percentage of solids in the mixture, to produce a linear solids Slow rate signal. The computations in this system are performed by Sorteberg pneumatic relays. Having obtained this measurement, integration and automatic control of hydraulic solids flow are available. This system is useful in mining, drilling and dredging industries. It provides maintenance of the net solids flow rate and reduces power consumption. Automatic control will provide rapid stabilization of net solids flow rate and release operators from making menual adjustments. The advantages of this application are economy of operation and increased pump efficiency, This paper describes a hydraulic solids flowmeter system installed aboard a dredge. Its purpose is twofolds:- 1. 20 provide a summation of the net solids flowing 2. To make available a practical guide for the drag tender operator. (Dwg. GSD-2219)

Jan 1, 1958

By M. J. Virnig, G. A. Kordosky

Throughout time, the mining industry has been very successful in meeting the world's requirements for metals and materials while meeting the challenges of decreasing ore grades and increased emphasis on protection of the environment. This success has been due to the development and implementation of new technologies. A clear example of such a development over the past 25 years is the increasing use of leaching/solvent extraction/electrowinning for the recovery of copper from oxide and sulfide ores. The key to the successful introduction of this technology was the discovery and development of the hydroxyoxime liquid ion exchange reagents by General Mills Chemicals (now Henkel Corporation). An important role was also played by the close working relationships between General Mills Chemicals and Ranchers Exploration which resulted in startup of the first plant in 1968 and between General Mills Chemicals and Bagdad Copper which resulted in the startup of the second copper SX-EW plant in August of 1970. Following on the heels of the hydroxyoxime development came the commercialization of other new chelating reagents based on different chemical functionalities, i.e., beta-diketones, alkylated 8- hydroxyquinolines and sulfonamidoquinolines. This initial spurt of activity was then followed by a slowing of development in terms of new reagent functionalities. Activity has continued in terms of further optimization/improvement of existing reagent functionalities but the commercialization of new reagent functionalities has slackened. This observation reflects the fact that the development of new reagent functionalities for metal recovery has become increasingly more expensive such that the right combination of price and sales volume must exist in order to justify the investment required to bring a new reagent to the market place. Given the dependence of the mining industry on innovation to meet the needs of the future, one can ask how these new developments, particularly in new reagents, will occur. To arrive at an estimate of the costs involved in commercializing a new metal extractant functionality, particularly a chelating type functionality, a case study of the development of LIX ®* 34

Jan 1, 1994

By Peter Werner

Technological advances in mine equipment and milling processes have enabled mining companies to exploit ever lower grades of ore. The result has been larger disturbances, greater volumes of waste, a complex web of infrastructure, and an overall trend towards mega-projects that can extend over several square kilometers. This explosive growth in a mining operation’s disturbance footprint provokes an obvious question: What’s it going to cost to reclaim all of this? At face value, this can be an enormous financial liability for a company, but since the timing of reclamation may be years in the future for many operations, these costs can be heavily discounted thereby limiting the burden on the corporate balance sheet. Nonetheless, mining companies are eager to remove these liabilities as quickly as possible, conversely, regulators want assurance reclamation will, in fact, occur. How might one bridge these competing interests? Navigating the practical and financial requirements of a post-closure landscape requires foresight, judgement and assumptions, however, companies who do not adequately plan for these future expenditures when there is no off-setting income stream will likely face some difficult decisions. Simple risk analysis tools and utilizing the time value of money can help bring some clarity to this end-of-mine life phase.

Feb 1, 2025

By Erle I. Shobert

In the comparison and consideration of synthetic and natural materials, graphites represent a situation in which natural graphites amount to less than 10% of the total carbon and graphite production by weight, and less than 5% in dollar volume, There are few applications where it could not be re- placed by synthetic graphite. On the contrary, synthetic graphite materials can be engineered to cover an extremely wide range of applications. These include electrographite brushes for rotating machinery, pyrolytic graphite, graphite-impervious pipe, nuclear moderators, high purity spectrographic graphite, power tube anodes, graphite rotary shaft seals, and rocket nozzles. The special qualities of natural graphite and its limitations are delineated and the almost unlimited possibilities in artificial graphite materials are discussed.

Jan 1, 1964

By Philani Larrance Ngwenyama, Ronald CW Webber-Youngman

The survival chances of trapped miners in underground mines depend on how quickly they can be located and rescued post-accident. During entrapments, emergency rescue is highly desired but can be hindered by the lack of positioning information when a fit-for-purpose missing-person locator system is not available. Various types of missing-person locator systems are available to aid search-and-rescue operations. From the wide range of the available systems, selecting the most suitable one becomes the next challenge. The available systems have not been measured if they are fit-for-purpose or not, and to what situation. This study proposes user requirements that can be used as a guideline to facilitate the system selection process. These user requirements provide a framework for the design and development of a fit-for-purpose missing-person locator system. The user requirements can also be used for evaluating the performances of a particular system, predict its success, and also drive future research toward developing new technology to enhance the capabilities of the current systems.

Apr 1, 2024

By A. A. El-Midany, R. M. Farag, A. M. Salem, S. E. El-Mofty

Bentonite is one of the main players in the stability of drilling mud. Its particle size and particle size distribution significantly affect drilling mud’s rheological properties. Although the Specifications for Drilling Fluids Materials report on Oil Companies Material Association (OCMA)-grade bentonite states that the API recommended powder having 2.5 percent mass fraction as the maximum value of residue of diameter greater than 75 μm, there is no other information on the specific size distribution for API bentonite. It was found that API bentonite has a specific size distribution with specific mixing weights. It is important to investigate why that mixture represents the optimum properties of drilling mud and how each individual size fraction has a specific function in the mixture. To clarify the effect of individual size as well as the collective effect of the size distribution, API bentonite was classified into different size fractions, with each tested separately for controlling properties such as filtration loss, plastic viscosity, gel strength, cake thickness and packing density.

By Robert L. Russell

The Bunker Hill Mine, located in the Coeur d'Alene Mining District at Kellogg, Idaho, has been a major producer of lead-silver-zinc ores since its discovery in 1887. The mine has produced over 29 million tons of ore from some 20 to 25 veins and ore zones, and now covers an area approximately one mile in length and one-half mile in width. The active section of the mine extends from 2500 ft above sea level to 1600 ft below sea level. Production is presently at the rate of about 1700 tons of ore per day. A two-mile adit, the Kellogg Tunnel, at the 2500 elevation, provides access to the main shaft area. Ore is hoisted to the adit level through a 5000-ft, 500-inclined shaft, extending to the lowermost haulage level 1200 ft below sea level. Primary shaft service for men and materials is supplied by three major internal, inclined shafts equipped with double-drum hoists. Present production requires ten levels to serve for mainline track haulage. These range up to 5000 ft in length and are either 200 or 400 vertical feet apart. Also, many intermediate levels exist throughout the mine. The conventional and autoloader mechanized square-set and cut-and-fill mining methods used throughout the mine have been the subject of a recent paper(l). One-third of current production is from vein-type ore bodies which are long distances from main shaft areas. Such veins generally dip about 450, have relatively narrow widths of from 3 to 20 ft, and usually contain less than 500,000 tons of ore. For many years, ore bodies thus situated have been developed by means of a separate inclined, timbered service shaft-raise connecting two or more main haulage levels. These commonly range from 400 to 1000 ft in vertical extent and are equipped with 25 to 50 hp electric, single-drum hoists. Intermediate levels are driven as conventional track drifts at 100-ft vertical intervals between the haulage levels. Ore and waste from the intermediate levels are trammed to orepasses for delivery to the lowermost haulage level servicing an ore body. The final result may be visualized as a number of small mines within a large mine. The problems of high development costs and high total development time, and the large amount and high cost of providing materials handl ing and ore haulage service while producing from this isolated type of stope block, made it desirable to consider totally new approaches in developing and mining a number of similar areas.

Jan 1, 1971

By Karen M. Kessen

The isotopic variations of lead from Mississippi Valley galenas have long been used to place constraints on the sources of the lead, and on the residence the of the lead in crustal reservoirs prior to its emplacement in the Mississippi Valley province. Similar studies based on strontium isotope variations in gangue minerals associated with the lead-zinc sulphides have been neglected until Haden's (1) study of such minerals from several localities in northwestern Ohio. His work revealed two things about the mineralization. Firstly, it shoved that the average isotope composition of lead from galenas from northwestern Ohio lies on the anamalous lead line characterizing Mississippi Valley-type leads, albeit at the least radiogenic end of the entire data array. This confirm earlier assignments of the Ohio mineralization as Mississippi Valley-type (Hey1 and others (2)). Secondly, Haden (I) showed that the strontium in the calcite, strontianite and fluorite is broadly similar in isotopic composition to the strontium in the host Silurian to Devonian marine carbonates within which these minerals arc emplaced. He concluded that the mineral strontium my have been very locally derived, from the carbonate hosts.

Jan 1, 1979

By Mirza Muhammad Zaid, Nana A. Amoah, Ping Chang, Guang Xu, Ashish R. Kumar

The key takeaway of this study is the significant improvement in dust protection for roof bolter operators in underground coal mines. The optimized canopy air curtain (CAC), with a redesigned two-level manifold system, provides uniform airflow distribution that effectively reduces dust exposure. By enhancing the protection of operators from harmful respirable coal and silica dust, this technology can reduce the risk of diseases such as coal workers’ pneumoconiosis (CWP) and silicosis. The application of this optimized CAC design in real-life coal mining operations can dramatically improve worker health and safety by minimizing dust-related exposure, ensuring compliance with industry regulations and prolonging the lifespan of mining equipment by reducing dust accumulation.

Dec 1, 2024

By J. O. Leppinen

FTIR measurements using a special ATR cell were carried out to investigate the adsorption of two thiol collectors, potassium ethyl xanthate (KEX) and sodium diethyl dithlophoshate (NaDTP), on an unoxidized lead sulfide surface. Both qualitative and quantitative determinations of the collectors were made at the coverages from two monolayers down to 2% of the monolayer. The experiments revealed that the thiol collector species coordinate to the lead atoms at the surface of lead sulfide but the surface products distinctly differ from the precipitated bulk lead compounds. There exists a linear relationship between the coverage and the signal intensity of the IR spectra within the coverage range studied.

Jan 1, 1987

By James R. Strong

Before getting into the subject of packaging and materials management, please permit me to introduce you to MICRO SWITCH. MICRO SWITCH, A Division of Honeywell Inc. is located in Freeport, Illinois. We manufacture and market thousands of types of precision snap-action electrical switches. Most of them are used as components by other manufacturers in industrial and commercial products. MICRO SWITCH also offers a broad line of industrial control devices including heavy- duty limit switches, relays, manual controls and proximity switches. Other product lines are solid state keyboards for the computer industry and high-performance d.c. motors used in computer related equipment. So you can see that we are a component manufacturer. With the exception of the keyboards, every one of our products would "fit comfortably into a breadbox." Some are so tiny that one could easily fit several thousand into a man's hat. In my position as supervisor-packaging. package design, and materials handling engineering, I am actively involved in package design projects, parts handling design projects, and numerous activities involving departmental layouts, storage facilities, and material handling equipment. Two package design technicians, a materials handling engineer, and a materials handling technician make up the technical staff.

Jan 1, 1973

By Peter Werner

Technological advances in mine equipment and milling processes have enabled mining companies to exploit ever lower grades of ore. The result has been larger disturbances, greater volumes of waste, a complex web of infrastructure, and an overall trend toward mega projects that can extend over several square kilometers. This explosive growth in a mining operation’s disturbance footprint provokes an obvious question: What is it going to cost to reclaim all of this? At face value, this can be an enormous financial liability for a company, but since the timing of reclamation may be years in the future for many operations, these costs can be heavily discounted, thereby limiting the burden on the corporate balance sheet. Nonetheless, mining companies are eager to remove these liabilities as quickly as possible; conversely, regulators want assurance reclamation will, in fact, occur. How might one bridge these competing interests? Navigating the practical and financial requirements of a post-closure landscape requires foresight, judgement and assumptions; however, companies that do not adequately plan for these future expenditures when there is no offsetting income stream will likely face some difficult decisions. Simple risk analysis tools and utilizing the time value of money can help bring some clarity to this end-of-mine life phase.

Dec 1, 2025

By D J. Bradshaw

It is well known that the chemical environment determines the success of the flotation process, however its characterization and control is difficult to achieve. This work evaluates the use of various measurements, including mineral potential measurements, in gaining an understanding of the influence of varying parameters such as the milling media and the reagent suite composition on the flotation performance of a platinum group metal (PGM) bearing ore. The results showed differences in the response of the various mineral electrodes to the different conditions, however the changes in flotation performance of the different minerals in the ore could not be wholly described by the electrochemical changes, demonstrating the limitations of these measurements.

Jan 1, 1999

By A. G. Mayton, D. H. Ambrose, C. C. Jobes, N. K. Kittusamy

In a systematic study, the National Institute for Occupational Safety and Health (NIOSH) evaluated seat designs in low- and mid-seam shuttle cars during production operations at two underground coal mines in southern West Virginia. The purpose was to support, with additional data, earlier findings that NIOSH ergonomic seat designs (featuring viscoelastic foam padding and lower-back support) may help reduce health risks to operators of coal mine shuttle cars. Eight shuttle car operators evaluated seven seat designs (one already in use in each vehicle and five NIOSH designs) relative to perceived and measured whole-body vibration (WBV) exposure (including vehicle jarring/jolting) and discomfort. Operators’ perceptions using a visual analog scale (VAS) and questionnaire ratings were compared with International Standards Organization (ISO) 2631-1:1985 fatigue-decreased proficiency (FDP) limits and measured WBV levels on low- and mid-seam shuttle cars. Objective and subjective data results indicated that NIOSH seat designs (with added adjustability, lower-back support and improved seat padding) performed better to reduce vehicle jarring/jolting levels and that shuttle car operators favored them over existing seat designs. The NIOSH low- and mid-seam shuttle car seats showed 45 to 77 percent better performance in FDP and 9 to 60 percent better performance overall in operators’ ratings. Considering the VAS results for low- and mid-seam shuttle cars under no-load conditions, operators rated the level of jarring/jolting 18 to 89 percent lower with the NIOSH seats. Reductions in measured vehicle jarring/jolting were 19 to 46 percent for the three-directional vector sum accelerations relative to the existing seats on the low- and mid-seam shuttle cars. Questionnaire responses indicated that operators for both shuttle car models rated NIOSH seat designs as more comfortable overall. Vehicle operators most frequently suggested adding armrests to improve the seats on the mid-seam shuttle car. A suggested improvement for the low-seam shuttle car was to make the seat a better fit for the operator compartment, which would enhance clearance between the operator and vehicle controls and allow for better seat adjustment and operator visibility.

Jan 1, 2009