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By A. Wahab Khair, John G. Oldsen, John C. Stankus, Song Guo

During the last several years, implementation of trusses, in lieu of wood cribs, has been successful for supplemental tailgate support in the Pittsburgh seam. This paper reviews, the truss support system provided by the new high strength 0.6" tensioned cable truss, which is now also being used in cribless tailgates. Cable loading and roof deformation were monitored to evaluate roof and floor performance. The test results indicate that the cable truss system successfully controlled the roof and floor during the first and second panel extraction. This paper will describe the advantages of cable trusses and their load transfer mechanism as well as mine evaluation.

Feb 24, 1997

By R. H. Seraphim

The name is derived from an Egyptian myth, "A beautiful lone bird which lived in the Arabian desert for 500 or 600 years and then consumed itself in fire, rising renewed from the ashes to start another long life." HISTORY This account of the first history is gleaned from old reports and documents which are listed in the Bibliography and from discussions with old-timers of the district. Prospectors were active in the vicinity of Greenwood in 189 1, and in that year staked the Mother Lode, Crown Silver, and Sunset. Henry White staked the Knob Hill claim in Phoenix on Jul. 15, 1891, and by the end of the year, other prospectors had staked most of the claims covering the valuable ore bodies in the camp. Much surface work done in the early years indicated that the values in copper, gold, and silver were low. Large capital investments were required to develop the ore bodies and build smelters. The discovery that the ore was practically self-fluxing greatly enhanced the value of the deposits. A map of the area showing the geology is given in Fig. 1. The bedded Brooklyn conglomerate is shown in Fig. 2.

Jan 1, 1991

By Hal McVey

"Philosophy" addresses the definition and assigning of importance to the marketing of by-products. Two examples, one in metals and the other in industrial minerals, explore prime product to by-product relationships. Relative revenues from all products illustrate the importance of by-products to economic feasibility. "Mechanics" takes a broad view of the types of marketing organizations that are applicable to individual circumstances in the marketplace. In-house marketing as well as agents, merchants and trading companies are outlined and discussed. Philosophy Definition Of Terms Philosophy Definition Of Terms The definition of terns for a paper such as this is generally a necessary but not-very-interesting exercise. However, in simply trying to clearly define the term "by-product" some interesting relationships between products arise and the line of demarcation between "product" and "by-product" often becomes obscure. The search for that distinction represents the philosophy portion of the title. A couple of definitions of philosophy can even help to set the tone for what follows. According to Webster, philosophy is : 1 Pursuit of wisdom. 2. A search for a general understanding of values and reality.

Jan 1, 1983

By Charles C. Dahl, Gordon C. Presley, Andrew E. Nevin, Bruce A. Kennedy

How does SME-AIME cope with profound changes in technology, markets - and most importantly - in employment patterns facing its membership today? This is the question that prompted the Society's Board of Directors to appoint a Long-Range Planning Commission (LRPC) (see ME, Feb. 1984, pp. 118 and 128). This is also the question addressed most particularly by the LRPC's Scope Committee. The Committee started its deliberations by asking such basic questions as "Who are we?" and "What is our business?" The Scope Committee then reviewed the findings and recommendations of other more specialized committees to develop and integrate their concepts of the Society's business for the next 10 years. The policy-making suggestions of the LRPC were reviewed and acted upon by the Board of Directors at its open meeting in Los Angeles on Feb. 26, 1984. At the Oct. 23-26, 1984 SME Fall Meeting in Denver, the Board will again review LRPC recommendations. In answer to the question "Who are we?" the Scope Committee proposed description, which was accepted by vote of the board of directors: . . A technical and professional organization that consists of individual members, namely those mining engineers, metallurgists, geologists, earth scientists, economists, managers, educators, and other professionals concerned with all facets of exploration, production, distribution, and using of mineral commodities. "These mineral commodities include all metals; industrial minerals, including construction materials and fertilizers; coal, oil shales, tar sands, and other mined fuels. Among the earth's mineral resources, only wellpumped oil and gas lie outside the Society's specific purview. "Traditionally, SME members work in the fields of engineering, technology, exploration and discovery, development, construction, mining, quarrying, beneficiation and processing, handling and transport, equipment manufacturing, sales and marketing, data processing, safety, land reclamation, environmental protection, taxation, administration, and management of these elements. "Members practice their professions in industry, in universities and research institutions, and in government. They may be operators, manufacturers, sales persons, contractors, consultants, analysts, researchers, educators, advisors, regulators, or members of supporting staffs. "The members of the Society are leaders in dedication to their crafts, in innovation, and in the pursuit of excellence. Among their numbers they count the most distinguished of engineers, applied scientists, and managers. "The Society is based in the United States, is active on a worldwide basis, and is open to nationals of any country. Certain qualifications must be met for attaining and maintaining membership." Purpose of the Society As to the question "What is our business?" the Scope Committee restated our purpose in light of current practice and the constitution of AIME and the bylaws of AIME and SME. The Board of Directors accepted the following proposed purpose of SME: "To further the professional development and well-being of its members by publishing and distributing technical writings, news, and information; by sponsoring meetings of members; by providing forums for discussions and for continuing education; and by fostering communication on the subjects within its purview. "The Society assists educa-

Jan 4, 1984

By S. Y. B. Subbarao, K. Ravindranath

Lead and Zinc concentrates are being recovered at Rajpura- Dariba (Distt. Rajsamand, Rajasthan, India) from a complex multi metal sulphide deposit since 1984 by selective flotation employing a large number of reagents. The cost of concentrates' production has been high. Due to the increased availability of concentrates world over and to be competitive, it is necessary to reduce cost of production. An effort has been made by the R.D. Department of Hindustan Zinc Limited to bring down the cost by resorting to production of Bulk Pb + Zn concentrate with enough Ag to make it attractive to the smelters. This paper gives an account of open cycle testing and locked cycle testing in the Dowa Continous Mini Flotation unit. The metallurgical data generated in the mini flotation unit indicate the possibility of obtaining smelter-acceptable bulk concentrates containing Pb+Zn 45%, Ag 400 ppm and graphite carbon about 3%. An in-plant trial in the 3000 TPD concentrator indicated that there would be savings through dispensing with and reduction in some reagents, lower power requirement, etc. Also, a substantial increase in revenue is expected due to higher recoveries by resorting to bulk concentrate production as against individual concentrates.

Jan 1, 1995

By F. Habashi

Asbestos, an extremely useful natural resource, has been studied extensively mineralogically and for industrial application. Its extraction from ores has been greatly improved with respect to safety in the work place. In spite of that, there is a decisive effort in many countries to ban its use on the grounds that it is a toxic substance. This action resulting in drastic decrease in production and the possibility of destroying the industry. The chelation of asbestos with organic dyes seems to be a promising way to abate its toxicity. Dyeing can be done when the fibers are slurred in water at ambient conditions in the same way as textile fibers.

Jan 1, 2009

By M. C. Williams, T. P. Meloy

For over thirty years the Population Balance Model, PBM, has been the mainstream modeling method for comminution unit operations and comminution circuits. For commercial comminution circuits the method is based on erroneous physics and dubious numerical mathematical methods leading to non unique solutions that have little extrapolative value and faulty control strategies. In short the PBM is wrong. Given is a detailed analysis showing a number of non trivial flaws in the linear PBM. Moreover, a simpler model is presented that leads to a solution of the comminution circuit predicting the size distribution output over a variety of conditions. Because the linear PBM is firmly entrenched, an award is offered, $10,000, to any researcher that can use the linear PBM and its present numerical methods to predict the typical straight line, self similar, output of wet mills over a variety of grinding times.

Jan 1, 1992

By Jayant Khambekar

In a typical mining operation, run-of-mine (ROM) ore is crushed and screened to achieve a desired particle size distribution and then fed to processing equipment for further refining. For an operation to be profit-able, the ore handling system from the mine face to final product loadout must be reliable. However, the handling system components do not always perform as expected and production problems related to material flow occur. These problems include flow stoppages, limited live storage capacities, uncontrollable flow, segregation, spillage and dust emissions. These result in lost production, excessive maintenance, safety and environmental issues, and even structural failures, in some cases. Flow patterns Flow problems and their solutions can be best understood by first learning how bulk solids flow. As bulk solids discharge by gravity from a storage system, primarily two types of flow patterns can develop: funnel flow and mass flow. Figure 1 shows a schematic of these two flow patterns. In funnel flow, only a portion of the material is in motion during discharge, which flows toward the outlet through a channel that forms within the stagnant material. Funnel flow occurs when a hopper is not sufficiently steep and smooth to ensure flow along the walls or when the outlet is not fully effective. In mass flow, all of the material is in motion whenever any is discharged ? there is no stagnant material. Mass flow occurs when the hopper is sufficiently steep and smooth to ensure flow along the hopper walls. Shallow valleys are not permitted and the outlet must be fully effective. A third type of flow pattern, called expanded flow, can develop when a mass flow hopper (or hoppers) is placed beneath a funnel flow hopper or bin. The mass flow hopper is designed to activate a sufficiently large flow channel in the funnel flow hopper to avoid flow problems due to a rathole. The flow pattern in which a bulk solid discharges from a storage system strongly influences the flow problems that may occur in that facility.

Jan 1, 2009

By Robert L. Somerville

As more phosphate deposits are discovered and new mines are developed, the necessity of critically evaluating various rocks for phosphoric acid production recurs ever more frequently. This need is accentuated by the increasing number of, fertilizer plants being constructed on deep water at various locations to serve world markets and to take advantage of locally-available sulfur or sulfur-bearing ores. A major proportion of all phosphate rock mined is consumed by wet-process plants and this acid in turn is consumed, usually captively, in the manufacture of fertilizer. It is apparent, therefore, that the first question asked by the developer of a new deposit is - How will it work in a wet-process plant? and conversely, when developing a deep water, project, one of the early studies required is - Which of the available rocks shall we use? What is the correct price to pay? How do we compare one rock with another? The economic importance of even minor aspects of these questions

Jan 1, 1966

By Eleanora I. Robbins, Motoaki Sato

Many problems associated with acid mine drainage (AMD) are caused by the complex way molecular oxygen (O2) oxidizes reduced matter at surface temperatures. In aqueous solution, O2 kinetically "prefers" to go through the formation of hydrogen peroxide (H2O2) as an intermediate. Being innately unstable, H2O2 is quickly decomposed back to water and oxygen in the presence of dissolved Fe and Mn, both catalysts for the decomposition. Direct addition of H2O2 to AMD produced similar results. Ozone (O3) is a much faster and stronger oxidizer than either O2 or H2O2. In the laboratory, O3 rapidly precipitated Mn, Fe, Ni, Co, Pb, and Ag even in acidic solutions. The experiments indicate that AMD can probably be processed with ozone and metal oxides/hydroxide recovered in flow systems using only septic-tank-size reactors and small sedimentation ponds.

Jan 1, 2000

By V. E. Cole

For the successful execution of a major project, the project team must be thoughtfully organized, manned, instructed and motivated. This is true of both the engineer/constructor team and the mining company team. Then these teams must be carefully related so that they function effectively as one organization on the job. This paper describes the organizing techniques and the human ingredients and know-how of a successful project.

Jan 1, 1980

By Charles A. Rhoades

The Bureau of Mines is conducting research on a dual leaching method that offers the potential for the economic recovery of the silver as well as the manganese contained in some of the domestic manganiferous silver deposits. The method is an initial leach of the manganese with aqueous SO2 followed by a neutralization rinse, and then by a second leach for the extraction of silver with cyanide solution. Refractory silver in these ores is either bound by the high-valence manganese, chemically resistent to cyanide leaching, or is rendered inaccessible to cyanide leach solution by the surrounding manganese mineralization. Less than 10 pct of the silver was extracted when -1 in +1/2 in (-2.5 cm + 1.3 cm) ore pieces were leached directly with cyanide. However, extractions of 25 to 82 pct for silver and 65 to 96 pct for manganese were attained in laboratory column leach tests using the dual method on the same size ore pieces from six domestic deposits.

Jan 1, 1984

By Burke Trafton

An earlier paper1 introduced a rapid solution for mine ventilation network problems, employing the digital computer. In this paper, refinements and additions to the computer program which expand its scope of application and a solution to a ventilation network having a coal-mine configuration are presented. Specifically, the revised program--written in FORTRAN for the IBM 7074 computer in Penn State's Computation Center--is applicable to any mine ventilation network employing natural splitting and having its fan located externally. It accomplishes the following; 1. Distributes an assumed total quantity of air flow among all air- ways of the network, performing iterations until an acceptable level of error is attained and the flow in each airway is known. 2, Computes the pressure drop (head loss) in all airways and the overall network and mine head losses. 3. Determines the operating point for the mine and a given fan, adjusting all air flows and head losses to the actual values.

Jan 1, 1964

By Tracy E. Barnes

The process of computerized reserve estimation consists of assuming a model of the spatial continuity of a deposit and then, working within the assumed model, estimating the grade and tonnage of the deposit. The basis for geostatistical analysis is a statistical definition of this continuity or the variogram. The true variogram is essentially impossible to define. So an experimental variogram is defined from the sample data and kriging proceeds assuming that this experimental variogram is a good approximation of the true variogram. Therefore the closer the experimental variogram is to the true variogram the better the estimate will be. Realizing that the variogram is nothing more than the definition of the spatial continuity of the deposit, taking the known geologic continuity of the deposit into account will give a superior variogram. The use of known geology is a widely recognized necessity for good structural analysis of a deposit, but is rarely fully incorporated into the structural analysis.

Jan 1, 1982

By Thomas E. Ban

During recent years fuel consuming industries of the United States have been caught between environmental restrictions and the uncertainty of obtaining an inexpensive fuel. With the advent of the National Energy Act of 1978 there has been added impetus to switch from gas and oil to coal. For industrial furnaces and boilers that were designed to bum coal, returning to an available compliance coal might be feasible. However, furnaces and boilers designed for gas or oil cannot reasonably be converted to coal unless the coal is initially gasified. All cases, nevertheless, depend upon the availability of an adequate structured coal of a compliance composition, a challenge to the coal mining industry. The foregoing problems have contributed to the current energy-coal crisis of today's economies. It therefore would be worthwhile to capitalize on previous experiences of the mineral processing industry.

Jan 1, 1979

By G. V. Krishnan, L. Adler

A rock classification for drilling and boring is presented covering most equipment types and providing an estimation of the key parameters for operation, such as thrust and speed, and of performance such as penetration rate and bit life. Drilling and boring are significant and integral aspects of both the mining and heavy construction industries. Together these constitute over 20% of the G.N.P. Drilling and boring represent the most arduous mechanical processes performed in industry. Their misapplication quickly leads to equipment destruction, hazards, and to major delays. The classification is unified in two ways: 1) for a particular rock class several parameters can be estimated, 2) the classification integrates most excavating activities (i.e. digging, ripping and even blasting), and is derived from ground control. The rock classification provides a job property, based on fundamental and index properties, which yields quick and rough estimates of vital information. However it does not obviate the need for a more thorough analysis, and maintaining field records. BACKGROUND In order to adequately describe a drilling operation the conditions, activity, and equipment must be characterized. Of these the major independent variables are the conditions. Conditions focus on the geologic mass and also consider whether the site is surface or underground. The primary component of the geologic mass is the rock type, detailed below in Rock Characteristics. The other components

Jan 1, 1983

By Mining Engineering

The 43rd Annual American Mining Hall of Fame Awards Banquet and Fundraiser, sponsored by the Mining and Minerals Education Foundation (MMEF), will be held Dec. 6 in Tucson, AZ. Each year, the MMEF honors a slate of individuals and companies who have made notable contributions to the advancement of the mining industry. This year’s distinguished nominees are: Kathleen L. Quirk, president and chief executive officer and a member of the board of directors of Freeport-McMoRan Inc. is the 2025 Hall of Fame Inductee. Quirk joined Freeport in 1989 and had responsibility for a broad range of corporate functions, including tax, investor relations, corporate development and treasury before being named chief financial officer in 2003. She was named president of Freeport in 2021 and became a member of the board of directors in 2023. As a senior member of the company’s executive team for more than 20 years, she has been instrumental in Freeport’s strategic planning and execution of company goals. During that period, Quirk was named Best CFO in Metals and Mining by Institutional Investor Research magazine on numerous occasions. She holds a bachelor of science in accounting from Louisiana State University.

Aug 1, 2025

By Ian Martin

A precious metals refinery’s switch to personal computer-based, three-dimensional piping design saved many hours in the design of a South African precious metals refinery. Bateman Minerals and Industrial provided engineering, procurement and construction management services for Impala Platinum Limited-Refineries’ new $60 million refinery in Springs, South Africa. This project is one of the largest platinum refineries in the world. Bateman evaluated a new design method during this project that involved developing a three-dimensional model for the project. The new method saved time by reducing the man-hours required to generate complete project documentation, including plans, sections, isometrics and material takeoffs. The new method also saved design and construction time by allowing designers to detect clashes before construction began.

Jan 1, 2000

By Martin Wehrli, Oliver Schneider

"MOTIVATION Tunnel construction companies must keep costs low, finish projects in less time and still meet the high quality and safety standards. Therefore, their main goal is always to optimize the tunnel excavation process. Traditional geodetical methods are used since more than 100 years to ensure an exact breakthrough of a tunnel. Evolving sensors, sensor fusion and increasing computation resources opened new fields of application for geodetic solutions in tunneling. These solutions offer new ways to reduce costs and risks in tunneling. INTRODUCTION Nowadays in tunneling, geodetical measurement methods are not only used for guidance, but also for various other applications. This paper gives an overview about where geodetical measurements are used today and highlights their benefits for safety and costs aspects. Furthermore, advanced solutions are introduced. In progressive projects, they have already become state of the art technology and are in use daily. STANDARD GEODETICAL MEASUREMENT APPLICATIONS In drill & blast tunnel construction processes, there are many standard geodetical applications used in the different construction phases, each having different requirements regarding accuracy. In the excavation construction stage, guidance tasks and setting-out of various positions is done by the foremen. Thanks to simplified measurement tools, the foremen are enabled to carry out these measurement tasks themselves without requiring deep surveying knowledge. In contrast, deformation analysis and network measurement campaigns need sophisticated planning and a profound education in surveying. Therefore, these tasks are carried out by surveyors. Profile control and as-built documentation is required in each construction phase. Depending on the requirements of the project, this task can be carried out either by the foremen or a specialized surveyor. Table 1 provides an overview over typical surveying tasks in an underground project including information about who is doing the job and the according accuracy requirements. The listed tasks are described in more detail below."

Jan 1, 2016

By William G. Pariseau, Mark K. Larson, Heather E. Lawson

Rational design based on engineering fundamentals is essential for the layout of safe, stable shafts and tunnels. Shafts and tunnels including winzes, raises, adits, and crosscuts are lifelines to the underground and must be secure. The contribution of this paper describes a significant extension in existing software previously developed for five important design problems in strata-bound mines such as coal, trona, salt, potash, and some large, lead-zinc mines. This extension in software allows analysis to proceed in three easy steps: (1) preparation of a strata properties file, (2) generation of the finite element model, a mesh, and (3) finite element program execution. Circular, elliptical, and rectangular shaft sections are available for a single shaft, twin shafts, and shafts in a row. Spacing of twin shafts and shafts in a row is a free parameter (pillar width). Tunnel shapes are the same as shafts but include the conventional arched back section. Dipping strata of variable thickness, depth and orientation relative to the excavation of choice are allowed. The analyses are three-dimensional. An elastic-plastic material model based on associated rules of flow and an N-type yield condition for isotropic, transversely isotropic, or orthotropic rock are used for all strata. Example analyses from several hardrock mines are provided to illustrate the three-step process including mesh plotting and plotting of selected results. The goal of this software is to advance mine design technology for improved miner health and safety.