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By F. Brost

In 1976, a decision was made to install a conveying system to transport ore 10.3 km (6.4 miles) from the new Eisenhower Partnership Mine to Twin Buttes. The system, supplied and installed by Cable Belt Limited, of England, represents a radical departure from conventional conveyor systems. The driving tension is applied through two endless wire ropes while the belt acts only as the carrying medium. Features of the system are a single 2240 kw (3000 hp) drive and a 60° angle bend. Construction was completed in two years. Full production was attained after several months' operation.

Jan 1, 1979

By Mike Lewis

"Descending several stories down a metal staircase into a shaft spanning a quarter city block -- soon to become Roosevelt Light Rail Station in Seattle, WA -- visitors are greeted with four perfectly round, precast concrete-lined horizontal holes leading deep into the earth. The sound of water trickling out from a small drainage trough can be heard over the faint echoes of construction within. Upon entering, the light is dim, but the air is clear with barely a dust particle flowing through the sunbeams. This type of air quality is only accomplished with diligent controls, and JCM Northlink, the company in charge of building the Northgate Link Extension Project, is taking those measures seriously.Commissioned by Sound Transit, JCM is a joint venture of three companies: Jay Dee Contractors, Frank Coluccio Construction Co. and Michels Corp. The tunnels JCM constructed are intended to provide fast, reliable underground rail service, as well as relieve one of the region’s most congested traffic areas. The $440 million project will connect the Northgate, Roosevelt and University District neighborhoods north of Seattle to the downtown corridor and SeaTac airport further south.The scope of this project includes excavation for two light rail stations, boring of two parallel 5 km- (3.3-mile) long light rail tunnels in six runs and the construction of 23 cross passages. Begun in 2014, Sound Transit estimates that crews excavated more than 382,000 m3 (500,000 cu yds) of soil and installed 7,352 precast concrete tunnel liner rings during the shaft construction and boring phase. Now that tunnel boring is complete, JCM is in the process of constructing the cross passages, which act as maintenance areas and escape routes for passengers. Throughout the entire process, the company has utilized atomized mist to control particle emissions.“Our dust control needs change at every phase of the project and don’t go away until the project is fully complete,” said a JCM safety representative. “We found that different dust suppression technologies were needed at different intervals, but atomized mist seemed to fulfill our needs at every step.”"

Jan 9, 2017

By John C. Nigro

Bench scale and pilot plant research was conducted using dolomites (CaO,MgO) lime as the basic additive in the preparation of self-fluxed pellets from a typical magnetic taconite concentrate (5.57 S_2). The specific objective of this investigation was to ascertain the viability of the magnesia lime pellets in high temperature oxidizing and reducing atmospheres. Pellet basicity and induration temperature were major parameters affecting fired pellet quality; temperatures ranging from 1,200° to 1,250" C appeared to be the most favorable for production of self-fluxed pellets with basesities (B) above 1.0. Comparison of the mechani¬cal and metallurgical properties of regular (acid) and self-fluxed pellets (B 1.55) produced under similar conditions in a modified grate pelletizing machine showed that the self-fluxed pellets were more resistant to abrasion and to high and low temperature reduction disintegration, an important consideration in commercial application. The Plus 3 mesh Linder index increased from 68 percent (regular pellets) to over 90 percent (self-fluxed pellets). The reducibility and swelling indices of the self-fluxed pellets were found to be comparable to the regular pellets.

Jan 1, 1972

By Armine F. Banfield

The Purpose of the Paper It is fitting that the first paper of a session on the Financial Aspects of Mining should be on the basic data upon which any financial discussion of a mining project must be based. The history of a mining project starts with exploration in an area considered geologically favorable for mineralization and culminates in the discovery of a body of valuable mineral material commonly known as a mineral deposit. Subsequently more detailed exploration establishes the approximate size, shape, tonnage and average grade of the deposit by surface and/or underground drilling, -surface trenching and/or underground workings. Some preliminary metallurgical testing and other studies, as required, are made at this time. Development work is then carried out to provide representative samples for determining flowsheet and metallurgical balances, preparing the deposit for production and establishing more firmly the grade and mining characteristics of the deposit. A feasibility study is then made of the engineering aspects of the project including the estimation of operating coats, the capital required to place the deposit into production, profit and return on investment. A valuation of the deposit

Jan 1, 1972

By F. Heivilin

If the past is the key to the future, we will have ?tough? times maintaining Industrial Mineral reserves we have and proving new reserves around our plants and in new locations. The tough times will come from resources being more difficult to find, more hoops to go thru to make them Proven or Probable reserves. As always, Industrial Minerals require competitive quality, location, and costs. Since in most cases the market has suppliers, you will have to take away customers from their present supplier. This may take years or not happen even with lower cost higher quality raw materials. To determine the finished cost for a new deposit you need to design, determine capital costs, and operating costs for a new plant . Stripping, mining, hauling, processing, and transportation costs are part of the equation. After satisfying that your costs are in line you will need to do production tests to make sure the process works on the ore. You may want to complete permitting before purchasing the property. If you are new in the business you will have to prove you can deliver the right quality, the right quantity, on time consistently year after year at lower cost to take away a customer. Without being in the market this will be hard. The cut off grades to enter a market may be much lower than sale indicates because a competitor often lowers the price to keep you out of the market. We have many more items to check before the new deposits can be put on reserves. Our old reserves will require drilling to check for new products and prove that they do not contain items that would make them unusable for our product line or cause permitting problems. Archeological checks, wetlands, more water discharge testing, county zoning, and endangered species are among many items that have been added to mine permits. There will be more. A 4-6 page mining permit becomes 30-300 pages and consists of 5-15 permits, any of which might be a fatal stumbling block. It is not guaranteed that we can mine what we have on reserves. We may fight and lose. Oil-Dri?s loss in Reno and LaPort?s in England are examples where permitting failed. The NOx, sulfur, and carbon problems are just starting. Dioxin is in the background requiring monitoring on food products to Europe. What other anions, cations, endangered species, and land types are going to be problems in the future are guesses now. What new products are we going to have to test for and cause out of balance reserves? If there are none we probably won?t be here. We are competing for land use with ?Endangered Species?, wetlands, farming, forestry, cities, roads, and hunting. We?ve mined the best quality, low overburden, easiest to mine and process raw materials. The price of land and taxes are increasing. Old royalties are 2-3 times the present acre value instead of 8-10 times the property value when leased. Land taxes are up. It was and is best that we get the land in Fee Simple Title. This isn?t always possible. However, plants are closing and people have overlooked, made mistakes in drilling or interpretation of deposits. These may be opportunities. China is eating up high quality ?Industrial Minerals ?which have caused prices to rise. We may need to change our cutoffs? in terms of smaller pit sizes and higher overburden ratios. This is money in the bank. Overburden ratios and other items increasing cutoff costs need to be rethought. Suddenly doubling cutoff ratios for overburden and decreasing pit sizes are good alternatives to looking elsewhere where we might not be able to mine for a number of reasons. The higher prices make them competitive, especially when a competitor goes out of business. However, our low overburden ratios and short hauls around our plants are not safe from new roads, condemnation by county or city governments (N. J.), zoning changes (Reno, FL., CA, and environmental regulation changes (Buffers GA, MS). New roads ?Interstates? can take reserves, increase hauling distances and reduce tons per load. Let?s combine the Refractories, fullers earth, and bentonite industries and use the last 40 years as a guide to the future looking for problems and opportunities. Some or most of the following will apply to other minerals. WHERE DO WE LOOK? First, on our own properties, those next to our properties and on properties near our competitor?s plants. Where the profit margin has increased, the distance from the plant and thickness of overburden we can use is increased. The thickness of clay is decreased. For new locations we pick the ideal location and look at deposits and closed or open operations in ever increasing distances away from that location. We need to be aware of: 1. Increased transportation costs a. Access to Roads -Backhauls b. Haul with doubles and triples c. Railroads - Loading on sidings - Ability to get switches - Cars/backhauls versus rates 2. Cost of building a new plant 3. Cost of infrastructure 4. Cost of repair or new equipment when purchasing an operating or shutdown plant. 5. Local, state, and federal mine and environmental permitting. When exploring around an established operation expect that property acquisition, drilling, mining, stripping, and hauling costs will be greater due to them having second, third, or even fourth the pick of the deposits. I found this in New Jersey looking for refractories and around Quincy, Florida looking for attapulgite. You may be able to get some better properties because the operating company has angered some land owners, their drillers missed the clay, or the property wasn?t available when they were actively exploring for reserves. You may have some product lines your

Jan 1, 2009

By W. W. Dudley

The U.S. Geological Survey, in support of underground testing of nuclear explosives, has developed a technique (Dudley, 1910) to predict the inflow of ground water to large underground chambers that are cylindrical in shape. By treating the chamber as a large-diameter well pumped at constant drawdown, the nonsteady discharge can be computed by the method of Hantush (1961) for analyzing flowing wells under leaky artesian conditions. In mining applications, whether for mineral recovery or for nuclear testing, the most serious departure from the conditions of Hantush's model results from the gradual enlargement of the opening under drained conditions. Inherent in the analytical technique is that the "well" is fully completed at the time that dewatering begins. Because safety is the prime concern, however, initial pumping systems or personnel evacuation procedures must be designed to handle the greatest conceivable inflow. DEFINITIONS Because somewhat different meanings are attached to similar words in different technical fields, the U.S. Geological Survey definitions (Lohman, 1970) of several hydrologic terms used in this report are given below. An aquifer is a formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells, and springs. A confining bed is a body of material lying stratigraphically adjacent to one or more aquifers and having a hydraulic conductivity distinctly lower than that of the aquifer. The total head (dimensions L) of a liquid at a given point is the sum of three components: (1) elevation head, he, which is equal to the elevation of the point above a datum; (2) pressure head, hp, which is the height of a column of static water that can be supported by the static pressure at the point; and (3) velocity head, hv, which is the height the kinetic energy of the liquid is

Jan 1, 1971

By R. S. Conti, M. R. Krump, C. P. Lazzara Ph. D., R. L. Derick, L. L. Chasko

A mine fire is one of the most challenging safety issues facing a mine operator and can occur at any location underground. The National Institute for Occupational Safety and Health (NIOSH) and the Twentymile Coal Mine, CO, conducted in-mine experiments to determine the capability of high-expansion foam for addressing underground fires. The tests were conducted in sloping entries with high-capacity diesel-powered foam generators. The following results were observed: a well-designed, maintained and properly operated high-expansion foam generator can propagate a foam plug hundreds of feet in steep upward-sloping (20%) multiple entries against a ventilation pressure; stoppings and partitions designed to contain the foam plug in upward-sloping entries must be substantially constructed; and the predicted quantity of foam concentrate can be significantly less than the actual amount used, due to foam losses, such as bubble breakage on dry surfaces. This paper describes the production of high-expansion firefighting foam and discusses the in-mine experimental tests and results.

Jan 1, 2010

By Thomas B. Dellinger

Since 1950, rotary-drilled, large-diameter holes, "big holes", with depths to over 300 feet and diameters of over 30 inches have become numerous and widespread. Fifty such holes have been drilled for access shafts to LPG mined caverns, Over 70 holes have been drilled for various other commercial activities. Over 150 holes have been drilled by the AEC for atomic testing purposes. These holes have ranged up to 300-inch diameters with 1600-foot depths, 120-inch diameters with 570-foot depths, and 72-inch diameters with 4800-foot depths. Equipment is now available to drill a wide range of ?big holes? for varied requirements. At least a dozen drilling contractors are participating or have participated in the drilling of "big holes". The accompanying tables show pertinent historical, technical and economic data on over 250 holes. The illustrations to be presented concurrently with this paper show the various equipment and accessories now in use. (See Appendix I for captions of illustrations.)

Jan 1, 1966

By Robert W. Bruhn

Ground movements associated with high extraction underground coal mining, such as pillar retreat and longwall, are some- times large enough to disrupt the ground water regime as well as damage buildings and other surface structures. A U.S. Department of Energy Bureau of Mines- sponsored subsidence study at Kitt Energy Corporation's Kitt No. 1 Mine near Philippi (Barbour County) , West Virginia has provided an opportunity to monitor the ground water response above a mine panel during both developmental and pillar re- treat mining. Findings concerning ground water effects presented in this paper indicate that total extraction mining produced significant water level declines in deep-lying strata but had little effect on water levels at shallower depths. Post-mining values of hydraulic conductivity were typically somewhat higher than pre-mining values. Changes in water chemistry associated with mining were not sufficient to render the water unfit for human consumption.

Jan 1, 1986

By Zhiguo Chang, QINGXIANG CAI, Ebelia Manda, IZHAR MITHAL JISKANI, XIANG LU, Wei Zhou, Saleem Raza Chalgri

The concept of mine safety is highlighted in the literature of sustainable mining but not extensively discussed. This study analyzes various aspects of underground and surface mine safety and emphasizes its importance in the context of sustainable mining. More specifically, this research attempts to find the relationship between mine hazards and demographic characteristics, examine and compare the perceptual difference among miners, and determine the impact of mine hazards on workplace safety and safety climate. Descriptive analysis, chi-square test, independent samples t test, and linear regression modeling were conducted to achieve study objectives. Results confirmed that mine hazards were significantly associated with age and experience. Miners perceived lower levels of management safety practices, followed by supervisor safety, coworker safety, and job safety. The analysis showed that underground miners reported lower safety scores than surface miners. There was a statistically significant difference between miners’ perception of safety climate (p < 0.05). The results showed that the higher prevalence of mine hazards predicts poor workplace safety and a low safety climate. The regression models revealed that mine hazards have a significant effect on workplace safety (p < 0.05) and safety climate (p < 0.05). In conclusion, the distinctive model of mine safety presented here contributes to the monitoring and design of comprehensive safety interventions and helps to better understand how certain factors interact on multiple levels to influence the overall safety of the industry. In this study, some suggestions are put forward to provide directions to develop a sustainable mine safety system.

Mar 27, 2020

By A. M. El Shafey, Ahmed W. Hussein, Ibrahim M. Gaafar, Mona M. Fawzy, Mohamed Diab, Mohamed S. Abu El Ghar

The Quaternary stream sediments of the Diit area, southern Red Sea coast, Egypt, were mineralogically studied for their content of economic heavy minerals. The study area covered approximately 450 km2 and included three main parts: Wadi and Delta Diit, as well as Diit lens. The mineralogical investigation revealed that these sediments contain considerable amounts of placer ilmenite, magnetite, zircon, sphene, apatite, garnet, and rutile. Also present, in minor or trace amounts, are uranothorite, monazite, xenotime, fergusonite, khatyrkite, and gold. The magnetic fractionation tests, supplemented with the XRD and SEM mineral analyses, indicated the presence of Fe-oxide minerals as wuestite, hematite, and maghemite accompanied with magnetite as products for hand magnet separation. Ilmenite separation was carried out using a high intensity magnetic separator at a current of 1 A, while the paramagnetic minerals (e.g., garnet, pyroxene, amphibole, epidote, monazite, xenotime, and fergusonite) were separated as magnetic fraction at a current of 3 A. The non-magnetic minerals (e.g., zircon, apatite and rutile, uranophane, uranothorite, gold, and khatyrkite) were obtained at 3 A current. On a mineralogical and geochemical basis, the present work suggests that Diit stream sediments should be considered as a potential source for Ti, Fe, Zr, Zn, and Cu after the physical upgrading processes for concentrating the minerals carrying the aforementioned economic elements.

Jan 21, 2022

By Chamila Jinendra Nanayakkara, Nimila Dushyantha, Amila Sandaruwan Ratnayake, Gayithri Niluka Kuruppu

Rare earth elements (REEs) are key ingredients in many advanced materials used in energy, military, transportation, and communication applications. However, the prevailing geopolitical dynamics and the rising demand for REEs have rendered the reliance on primary REE resources susceptible to future supply disruptions, posing a substantial risk to the availability of these elements for numerous applications. Therefore, it is imperative to undertake substantial initiatives in the extraction of REEs from secondary sources on a large scale to ensure the resilience of the supply chain. Permanent magnets, lighting phosphors, and nickel-metal hydride (NiMH) batteries are among the secondary sources with high potential for sustainable REE extraction. This review assesses the extraction potential of REEs from the aforementioned three secondary sources and their leaching kinetics and thermodynamics aspects. More importantly, state-of-the-art different existing kinetic models employed in rare earth (RE) leaching were well discussed for a better understanding of the REE leaching reactions. Furthermore, the optimized leaching parameters related to this kinetics were described, and various RE recovery methods were comprehensively summarized. These processes facilitate to managing one of the fastest-growing solid waste streams by minimizing environmental impacts and producing critical metals, including REEs via circular economy approaches. The recovery of REEs from secondary sources aligns with numerous United Nations Sustainable Development Goals (SDGs), particularly in the renewable energy sector for climate change mitigation. Consequently, this trash-to-treasure urban mining concept to transforming e-waste into a valuable resource for REE recovery emerges as a pivotal element within the REE industry.

Dec 28, 2023

By D. P. Bryan

An aggregate resource study was done for southern Washoe County, Nevada, which contains the Reno-Sparks metropolitan area and a population of about 300,000. The study included an inventory of existing operations, projection of future demand, identification of potential aggregate resources based on geology, and determination of economic potential of these resources. Economic potential was determined by the integration of GIS layers that included aggregate potential, distance from market, distance from major and minor transportation arteries, and elevation. The investigation resulted in a determination that resources of high quality aggregate sufficient for future consumption are present in southern Washoe county; the limiting factor for future utilization is accessibility.

Jan 1, 1996

By Edmond J. O’Donovan

South Bulga is a new longwall operation located in the Hunter Valley coal-mining region in Southeastern Australia. The mine’s objective is to achieve productivity levels significantly higher than the current industry average. From the day longwall production began, South Bulga’s output was below both budget and industry expectations, primarily because of the poor performance of the conveyor system. In the past, conveyor systems have been seen as an adjunct to the mine plan, not as an integral part. At past production levels, this approach may have been acceptable. In today’s mining operations, the conveyor system must be treated as integral and vital to the mining operation. The conveyor system is analogous to the vascular or circulatory system of the human body. Of itself, the system does not do anything, but if it is not functioning satisfactorily, the mine cannot operate.

Jan 1, 1996

By M. Guney, A. R. Bell

In Mindola mine on the Zambian Copperbelt, there is a plan to extend the current production level of 1.2-1.5 km (3,900-4,900 ft) with five additional production levels. Research work indicated that the present total heat output of 38.6 MW will inevitably increase to 63.2 MW in 25 years. Estimated WB and DB temperatures, representing the total heat generation in stope faces and development headings during these same periods are predicted to increase to 33.8/40.2°C (93/104°F) and 35.3142.10C (95/108°F) respectively. It is assessed that the nominal refrigeration capacity needs to be progressively increased to 9, 000 MW.

Jan 3, 1984

By C. B. Henderson

The development of slurries of coal and water as a boiler fuel replacing No. 6 fuel oil has been actively pursued at the Atlantic Research Corporation since 1976. Funding for this effort has been provided by the U.S. Department of Energy, the Electric Power Research Institute, and by corporate funds. The name ARC-COALTM has been selected for these slurries. Stable coal-water slurries with bone-dry coal loadings between 62% and 77% have been prepared, evaluated rheologically, and successfully burned in an experimental furnace without the assistance of other fuels. The advantages and properties of these slurries, including combustion results, are reviewed. Also discussed is the pilot line used for processing barrel quantities of fuel and a pilot plant capable of processing 600 bbl/day, currently being designed.

Jan 1, 1982

By Jason Swartz, Gerardo Gomez, Henry Leighton

San Antonio has experienced sustained growth for decades, putting increased pressure on existing wastewater infrastructure. In June 2013, San Antonio Water System (SAWS) reached a Consent Decree agreement that requires significant improvements to the wastewater system over a 10-year period to reduce Sanitary Sewer Overflows. One of the critical projects was the W-6 Upper Segment Tunnel project to reduce sanitary sewer overflows on an existing sewer main running through Lackland Airforce Base. The replacement project consisted of a new tunnel nearly 29,000 LF of primarily 104" FRP. The project also includes nine shafts and multiple trenchless crossings to make near surface connections to the new works.

Jun 23, 2024

By R. W. Sayers

The Duval Corporation porphyry copper deposits at Copper Canyon and Copper Basin, though widely separated, form an economic unit requiring integrated exploitation. Contrasts in mineralization, host rocks, and mode of occurrence present unique mining and milling problems. Mixed oxide-sulfide ore is treated in extensive dump leaching facilities in both areas. Complex copper-gold-silver ore is treated in a 4,000 tpd mill at Copper Canyon. In both areas, hypogene metallization occurs within large aureoles of metamorphism and hydrothermal alteration related to quartz monzonite intrusions of mid-Tertiary age. Supergene processes further altered the rocks and enriched the hypogene protore. At Copper Canyon, hypogene copper and iron sulfides with gold and silver occur in fractures, as partial replacement of favorable beds, and as disseminations in Paleozoic sedimentary rocks. The lower part of the Pennsylvanian Battle Formation was a particularly favorable host. Metallization occurs to a lesser extent in quartz monzonite. Metal zoning is well developed. The deposits at Copper Basin consist principally of supergene copper minerals in arenites of the Cambrian Harmony Formation. Oxidation of hypogene copper and iron sulfides in tactite zones has formed at least two commercial deposits; intersections of fractures with favorable beds exerted important ore controls.

Jan 1, 1968

By M. K. Larson

"Specialized numerical modeling codes have been developed over the years to estimate ground stresses during the excavation of coal in underground mines. One of these tools, MULSIM, a displacement discontinuity boundary element code, was last developed by Zipf into a version called MULSIM/NL [USBM 1992a, 1992b]. The code was used frequently in years past, but closure of the Bureau of Mines in 1996 marked the beginning of a pause in its development. A similar tool with distinctly different treatment of overburden idealization, LaModel, was subsequently developed [Heasley 1997] and largely displaced MULSIM/NL in the literature. However, recent work modeling deep western longwall coal mines [Larson and Whyatt 2013] has demonstrated that MULSIM has distinct advantages for regions with relatively stiff and strong overburden. This work required that MULSIM be revived and updated into a version called MulsimNL/Large. Updates include larger array sizes, greater precision, greater number of materials, and the addition of a five-point, six-segment pillar load/displacement model that provides the user a more flexible coal-strength model allowing hardening and softening before a final residual strength. MulsimNL/Large has the ability to calibrate to large load transfer distances observed in some western U.S. coal mines that appear to be caused by strong, massive units in the overburden and/or floor of a coal mine. Also, it provides the ability to calibrate gob stiffness to simulate measurements or estimates of overpanel weight distribution between gob and abutment, while still maintaining load transfer distance with minor adjustments. MulsimNL/Large can easily implement material strengths calculated from various pillar strength models. The five-point model gives MulsimNL/Large the ability to easily simulate pillar behavior that is extracted from detailed pillar models, such as FLAC3D. MulsimNL/Large or similar approaches should be considered for evaluating mining layouts where stratigraphic conditions are known to cause overpanel weight to transfer to an extent significantly longer than the empirical method widely used to calculate load transfer distances in the U.S. [Peng and Chiang 1984; Mark 1987; USBM 1990]."

Jan 1, 2015

By D. W. Alexander

In 1993, CONSOL began investigating new methods of permanently filling coal mine shafts, which after ventilation is stopped, may contain a potentially hazardous atmosphere. Fill materials such as fly ash/cement can be pumped, are non-combustible and non-incendiary but tend to flow into the mine entries. A non-flowable mixture has been developed that minimizes the volume of fill used. The paper presents our recent shaft filling experience including fly ash material properties, mix designs, field problems, placement success, and gas testing techniques.

Jan 1, 1996