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By Robert I. Fujimoto

The work described was conducted to develop standards for the application of wire rope clips on wire rope. These standards include optimum number of clips and clip nut torques for wire rope sizes 1/4 through 2-1/4 inches, when used for forming an eye attachment in wire rope. Wire rope test specimens with clip attachments were load tested on tensile testing machines to determine an effective combination of clip nut torques and number of clips for each size of wire rope to develop efficiencies above 90 percent of the catalog ultimate rope strength.

Jan 1, 1973

By S. S. Rowland

Good afternoon, ladies and gentlemen. It is a pleasure, for several reasons, to be here at this 13th International Conference on Ground Control in Mining. Of course it's always a pleasure to be able to see and reacquaint myself with many long-time friends; but it's also a pleasure, or 1 should say worthwhile, because I take something back with me, some knowledge about mining that lets me do my job better and more safely. if I can do that, I've accomplished my purpose in being at a conference such as this. This conference is a little different, though. I have to earn my stay. I have to earn it by telling you a story; a story about mining through a mile of rock to get from one coal seam to the same seam on the other side of an ancient river channel; a story about mine personnel taking over the job from a contractor; a story about having to mine through two faults after the hard part was supposed to be over, but, most importantly, it's a story about how it was accomplished successfully and safely by a group of ordinary coal miners possessed with determination, belief in themselves, and a "can do" attitude. If you can take any part of my story and use it to do your job better and more safely, then I will have accomplished my purpose in being here today. Kerr-McGee Coal Corporation's Galatia Mine is located in Southern Illinois near the town of Harrisburg in Saline County, about 350 miles south of Chicago and 120 miles southeast of St. Louis. Construction of the mine began in 1982, and the first coal was shipped in 1984 from the Harrisburg No. 5 Seam, 550' below the surface. Mining began in the Herrin No. 6 Seam, 100' above the No. 5 Seam, on April 1, 1985. Mining in both seams began by using the room-and-pillar method. In 1989, the No. 6 Seam was converted to longwall mining, as was the No. 5 Seam in 1992. Today, all mining is done by the longwall method except for the required development work, which is performed by continuous miners. A heavy-media preparation plant with a 4.2 million-ton annual clean-coal capacity processes the coal. By the end of 1994, with annual production now exceeding 4 million tons, we will have shipped over 30 million tons of steam and metallurgical coal throughout the United States and the world. Most of the coal has been used as the primary source of fuel to generate electricity for the city of St. Louis. The No. 5 Seam coal can be used as a semi-soft coking coal or as a high-Btu, relatively low-sulfur steam coal. Its use allows utilities to comply with Phase I of the Clean Air Act Amendments of 1990 without installing flue gas desulfurization units or blending with other coals. The Herrin No. 6 Seam is a high-Btu, medium-sulfur steam coal that requires blending to meet Phase I requirements. Because the No, 6 Seam coal does not meet the Clean Air Act Amendments' Phase I compliance standards, we were forced to cease mining operations in the No. 6 Seam, leaving 170,000,000 tons of minable coal in the ground. Last month the Galatia Mine became a single-seam operation mining the Harrisburg No. 5 Seam only. The Clean Air Act Amendments of 1990 and the resultant S02 emission limitations on electrical power generation plants effectively eliminate, beginning in 1995, the near-term potential for profitable mining of the Galatia Mine's high sulfur Herrin No. 6 Seam coal. Because of the Clean Air Act Amendments, it is virtually impossible to market high-sulfur coals like the No. 6 coal unless the mine location and mining conditions enable greatly depressed sales prices to cover costs. We, along with the majority of

Jan 1, 1994

By Zhibao Li, Kunming Zhai, Yan Zhang

The hydration kinetics of MgO, namely magnesia or magnesium oxide, obtained by calcination of magnesite MgCO3 or synthetic MgCO3·3H2O has been studied. Nesquehonite (MgCO3·3H2O) was prepared by the reaction of MgCl2 with Na2CO3 in a mixed-suspension mixed-product removal (MSMPR) crystallizer at 40 °C. Three magnesium oxide samples were obtained by calcination of magnesite MgCO3 or synthetic MgCO3·3H2O in muffle furnace at 900, 1100 and 1300 °C for 3 h, respectively. The hydration experiments of MgO samples were investigated at 25, 35 and 45 °C for 24 h in a stirred batch reactor. The hydration results indicate that the rate and extent of hydration of magnesia decreased remarkably with hydration temperature and increased with decreasing calcination temperature at a constant hydration temperature. The whole hydration reaction of magnesia was supposed to experience the promotive period and declining period. An empirical kinetic model ( k t p -?ln(1-??) ??) and a modification of the classical shrinking core model for diffusion control ( k t b d -?-?3 2 ????1 [1 (1 ??) ] ) have been applied to fit the experimental data of hydration in two stages, respectively. The values of kinetic parameters ( p k and d k ) were obtained by regression analysis and the activation energy of the sample at 900 °C was estimated to be 34.23 kJ/mol. The comparison between MgO from calcination of synthetic MgCO3·3H2O and a commercial MgO used in silicon steel production was carried out, indicating that special silicon steel grade MgO can be obtained by calcination of MgCO3·3H2O below 900 °C.

Jan 1, 2014

By H. A. Bilgin, A. Özgenog?lu, G. Kaçar

In this study, the influences of rock mass properties on the blasting performance in open cast mines are investigated. To this end, discontinuity spacings and discontinuity orientations are measured and full scale blasts with various designs are observed in open cast mines of Aegean Lignite (ELI) and Bursa Lignite (BLI) Establishments belonging to Turkish Coal Enterprises (TKI). For each blast, blasting cost is calculated, and particle size distribution representing the fragmentation of muckpile is determined by means of Split-Desktop software using image processing. 50%(K50), 80%(K80) passing sizes and topsize values are used in the determination of blasting performance according to rock mass properties. The relationships between orientation angle, which is the acute angle between the strikes of slope face and major discontinuity, and 50%(K50) and 80%(K80) passing sizes and topsize values and also blasting cost are investigated in order to analyse the influences of major discontinuity orientation on fragmentation and blasting cost. Furthermore, the relationships between discontinuity modal spacing (or block size index) and 50%(K50) and 80%(K80) passing sizes and topsize values and also blasting cost are investigated in order to analyse the influences of discontinuity spacing on fragmentation and blasting cost. In this paper, the trends observed in these relationships are discussed and the importance of it in mining is commented. Dans ce travail, Il a été traite les influences des qualites des rocheux massif sur les performances des abattages de l’excavation a ciel ouvert. Dans ce cas, les excavations a ciel ouvert dans les Entreprises Lignite d’Aegean et de Bursa qui appartient a La Societe Charbon de la Turquie; Il a été mesuré le trou du discontinuite et l’orientation du discontinuite et aussi, Il a été observé les abattages qui sont pareilles aux critaires exactes. Pour chaque abattages, Il a été fait le control des expences et la distribution du particle au dimension du pile qui a été deja abatté, a été trouve en utilisant le Software du Split-Desktop. Pour determiner les influences des qualites des rocheux massif sur les performances des abattages, Il a été utilisé K50, K80, et le plus grand valeurs des dimensions. Aussi pour determiner l’influence sur l’orientation du discontinuite majeur de la fragmentation et les expences de l’abattage, Il a été observé les relations entre l’angle de l’orientation ( C’est l’acutage entre la direction du banquette front et la direction du discontinuite majeur ) et les plus grand valeurs des dimensions et les expences de l’abattage. Plus, pour determiner des influences du trou du discontinuite sur l’abattage et la fragmentation; Il a été observé la relation entre l’index de la dimension du block et K50, K80 et les plus grand valeurs des dimensions et aussi les expences de l’abattage. Pour conclure; on peut dire que dans cette presentation, apres la discusssion des sujets consideres ces relations, Il a été souligné l’importances de ces relations dans la domain de la Minéralogie. In dieser Studie wurden die Einflüsse von Gesteinsmasse Eigenschaften auf die Sprengleistung in Tagebau Bergwerken untersucht. Zu diesem Zweck wurden Diskontinuität Abstände und Diskontinuität Orientierungen gemessen und Sprengungen im Originalmaßstab mit verschiedenen Anordnungen in Tagebau Bergwerken der Ägäischen Braunkohle (ELI) und Bursa Braunkohle (BLI) Betrieben, die zu der Türkischen Kohlegesellschaft (TKI) zugehörig sind, beobachtet. Für jede Sprengung wurden die Sprengkosten berechnet und die Teilchengrößenverteilung zur Darstellung der Aufteilung von Haufwerk ist durch Mittel von Teilbelegungssoftware, das Bildverarbeitung verwendet, bestimmt worden. 50% (K50), 80% (K80) durchlaufende Größen und Spitzengröße Werte wurden zur Bestimmung von Sprengleistung geordnet nach Gesteinsmasse Eigenschaften benutzt. Die Beziehungen zwischen Orientierungswinkel, welches der scharfe Winkel zwischen den Streichen der Hangfläche und Hauptdiskontinuität ist, und 50% (K50) und 80% (K80) durchlaufende Größen und Spitzengröße Werte sowie Sprengkosten wurden untersucht, um die Einflüsse von Hauptdiskontinuität Orientierung auf Aufteilung und Sprengkosten zu analysieren. Außerdem, wurden die Beziehungen zwischen Diskontinuität modal

Jan 1, 2003

By K. Sasaki

Diffusion phenomena in mine airways are important to trace gas and dust introduced into mine ventilation flows. Authors have carried out tracer gas measurements to check mine ventilation using concentration-time curves measured in mine airways, however dispersion mechanism to enhance effective diffusion have not been cleared. A numerical model using discrete tracer points dosed into tube flow has been presented to simulate their movements in consideration of turbulent velocity profile and fluctuation. Numerical simulations have been carried out to predict distributions of dosed points in tube flows with turbulent velocity profile, turbulent intensity profile and Reynolds stress. The numerical simulation results show that a combination of turbulent velocity profile and fluctuation creates extremely large dispersion of points in longitudinal direction and concentration curve with long tail was observed. This dispersion by velocity profile and fluctuation contributes large effective diffusion coefficient compared with original diffusion coefficient dominating in uniform velocity fields. Furthermore, the effect of Reynolds stress on the concentration-time curves is discussed.

Jan 1, 2009

By P. H. Reynolds, S. Liaghat, A. Zarasvandi

"Darreh-Zerreshk and Ali-Abad are two relatively small porphyry copper-type deposits in Yazd Province in central Iran. They are located within the central Iranian volcano-plutonic belt, formed above the collisional convergent margin of the Iranian lithospheric plate from the late Eocene to the Miocene. This paper discusses the geochemical characteristics of the igneous rocks, and 40Ar/39Ar geochronology of plutons and alteration phases associated with the Darreh-Zerreshk and Ali-Abad deposits. The deposits are spatially associated with igneous complexes that consist of older and barren granites intruded by intermediate-composition granitoids, which are the carriers of Cu mineralization. The granites have relatively high content of Nb, Y, and K, a prominent negative Eu anomaly, and were probably derived from melting of, or contamination of mantle-derived magmas by, continental crust. Porphyritic diorites, quartz monzodiorites, and granodiorites show enrichment in light rare earth and large-ion lithophile elements, depletion in middle rare earth elements, and have no negative Eu anomaly. These intermediate-composition granitoids were derived from melting of the upper mantle or lower crust, and their differentiation was controlled partly by fractionation of hornblende. A pilot K/Ar whole-rock dating study suggests that the pre-ore granites were emplaced in the Oligocene. Dating by the 40Ar/39Ar method of nine samples of secondary biotite and sericitized rocks from drillcore within the mineralized and altered zones in both deposits yielded a well-defined age of ca. 16 Ma. This date is interpreted to be the time of hydrothermal alteration and of porphyry copper type mineralization in this part of Iran."

Jan 1, 2007

By R P. Langford, T A. Moore

Indonesia over the last 15 years has experienced a surge in coal exploration, which has led to the development of a major export industry. This coal exploration has improved the understanding of the geology of the Indonesian coal deposits. The main economic coal deposits are of Eocene and Miocene to Pliocene age, which mainly occur in Kalimantan and Sumatra and were formed from peat deposits in an equatorial paleoclimate similar to that prevailing today. Some of these peats were domed peats, which grew above the normal water tables, under a climate of year-round rainfall; these peats grew above the level at which waterborne mineral matter can enter the system, resulting in low ash and sulphur, and locally very thick coal. It is believed that such peats have formed the unusually thick, low ash, and low sulphur Miocene coals of Indonesia. Coal deposits of Eocene age are typically characterised by thinner seams, with relatively higher contents of ash and sulphur. The Miocene coals and Eocene coals both appear to have formed in lacustrine, coastal plain or deltaic depositional environments, similar to the modern peat-forming environments of eastern Sumatra and parts of Kalimantan. The Eocene coals formed mainly in extensional tectonic settings. Miocene - Pliocene coal deposits formed in a range of tectonic settings; the most significant, for large economic coal deposits, are the foreland basin setting of the large Neogene coal deposits of South Sumatra.

Jan 1, 1999

By William M. Schafer

Forage plots were established on agricultural lands contaminated by acid mining waste. The acid produced through oxidation of pyrite and other sulfides caused elevated solubility and plant availability of copper, zinc, and arsenic which killed vegetation and polluted surface and groundwater. Soil amendments including agricultural lime (CaCO3), hydrated lime (Ca(OH)2), phosphorus, and organic matter were used to reduce the toxicity of metals. Several acid-tolerant grasses were used to vegetate the amended soils. Various soil extraction techniques were used to see which best correlated with vegetation performance. The extractions corresponded to three "forms" of metals in soil including soluble (water-saturation extract); plant-available/weakly adsorbed (DTPA extract); and total (HNO3/H202 extract). Of the extractants tested the DTPA levels appeared to correlate best with metal levels in plant tissue. The DTPA soil extractant serves as a useful tool in predicting potential phytotoxicity of mine waste materials.

Jan 1, 1989

By Jon G. Bredeson

The electromagnetic noise that exists in a mining environment is quite severe and was shown to have been reasonably well documented by a number of researchers in the Phase I Report. The noise levels are such that prudent communication design requires the careful use of all the electromagnetic noise data available. A comprehensive survey was undertaken to determine techniques used in various industrial environments to achieve secure communications in the presence of electromagnetic interference. The techniques were given in the Phase I Report and are rudimentary, but have produced reasonably good results. A number of these techniques could be applied to the mining environment.

Jan 1, 1980

By R. Tyreman, G. Ritson

"The Red Lake Mine is situated in Balmer Township, Red Lake area in northwestern Ontario. It is an underground mine that has been in production since 1948. The property was originally known as the Dickensen Mine and was shut down in 1996.A feasibility study was carried out in 1998 and it was determined that a new mill should be constructed with a throughput rate of 600 stpd. The life-of-mine average gold grade was projected to be 1.35 oz/t with gold predominantly associated with arsenopyrite and pyrite. Metallurgical testwork indicated that the optimal flowsheet for gold recovery would include an autoclave for oxidation with a carbon circuit for adsorption. To limit capital cost and establish cashflow, the mill was constructed without an autoclave. The recovery by gravity and cyanidation was projected to be 83%. A flotation plant was constructed at the tail end of the circuit to recover the additional gold associated with sulphides from the leach circuit tailings. This material is being stockpiled onsite for future oxidation treatment.Detailed engineering was started in early 1999 and the first gold was poured in August 2000. One feature of the project was the use of Contact Lake equipment from Cameco’s Contact Lake project. The entire mill was purchased and equipment re-used where possible. The capital cost for the process facilities was C$3 1.5 million."

Jan 1, 2001

By D. Turnbull, H. N. Treaftis

Precipitation of tin from Pb-Sn alloys (lead-rich) occurs by the nucleation and growth of hemispherical cells which consist of tin lomelloe interspersed in the depleted solid solution. Nucleation and growth of these cells and the tin interlamellar spacing at various compositions and temperatures have been investigated. The interlamellar spacing increases approximately as the reciprocal of the logarithm of the supersaturation ratio. For constant initial tin concentration the concentration of cell nuclei increases with decreasing temperature to a limiting temperature-independent value. The kinetic results support the view that the cell growth rote is governed by the diffusion of tin along the cell boundary. In the main, the results confirm the authors' earlier deductions, drawn from resistometric and calorimetric data, about the precipitation mechonism. IT has been shown1, 2 that tin (ß) precipitates from lead-rich (a) PbSn solutions by the nucleation and growth of cells (cellular or discontinuous precipitation). These cells consist of tin lamellae, with a spacing 1, interspersed in a depleted a solution. Reorientation of a also accompanies cell growth. The kinetics of cellular precipitation of tin from lead have been measured by resistometric2, 3 and ca1orimetric1, 3 techniques. The time-transformation isotherms (t equals time; x, volume fraction of specimen transformed) of the initial rapid precipitation, which drains about 60 pet of the tin from solution, have been described by a kinetic law having the form x = 1 —exp (—bt n) [I] where n usually has the value 3.0. It was shown" that this law and the other kinetic facts can be explained satisfactorily if it is assumed that the cells grow at a constant rate and that all the cells nucleate in a time negligible in comparison with the period of cell growth before impingement. Thus, for hemispherical cells b = (2/3)pNG3 [21 where G is the rate of cell growth in cm per sec, and N is the number of cell nuclei per unit volume. The rapid rate of cell growth at low temperatures can be accounted for"' if it is assumed that the dissolved tin drains to the lamellae edges by diffusion along the sweeping cell boundary rather than by diffusion through the a crystal (volume diffusion). For cell growth governed by cell boundary diffusion it was shown, approximately G=2(X° - X° / X° ) DBA / l2 where A equals the thickness of the cell boundary; D R, the coefficient of diffusion of tin atoms within the boundary; and X° and X, are the atom fractions of tin in the supersaturated and saturated solutions, respectively. Zener8 had already shown that, where

Jan 1, 1959

By Michael M. Hamilton

U.S. Bureau of Mines personnel examined mines, prospects, and mineralized areas to determine mineral resources and resource potential in and adjacent to the North fork Smith RARE II study area. Most mineral resources identified in this area are in laterites, highly-weathered residual soil zones. In the RARE II area, resources of nickel, cobalt, chromium, and magnesium were identified at 15 laterite properties and chromium resources at one chromite mine. Other commodities include copper, gold, silver, and mercury (fig. 1). Approximately 1,100 lode and 1,200 placer claims have been located in or adjacent to the area. Most placer claims are for literites. There are no patented claims or mineral leases. Forty laterite deposits on 15 ,properties within the RARE II area (fig. 2) contain about 16 million tons of identified marginal reserves and subeconomic resources containing nickel, cobalt, chromium, an magnesium (table 1). Most deposits have keen explored and are currently claimed. California Nickel Corporation is developing laterites on Gasguet Mountain, within and adjacent to the southeastern and western parts of the study area. If this project proceeds to production, a laterite processing plant on Gasquet Mountain would enhance the minability of other deposits in the study area. The Climax, PFM, DF, and Stone Corral properties (fig. 1, nos. 1, 6, 9, and 23) have deposits of sufficient tonnage and grade to attract mining interest; resources at these properties are in and adjacent to the RARE II area.

Jan 1, 1983

By C. F. McCarroll

The effectiveness of an industry?s safety activities can be gaged best by the accident records of that industry. In an effort to gage conditions in the petroleum industry, and with the objective of helping to reduce the number of accidents in it, the Bureau of Mines from time to time has tabulated, analyzed, and published pertinent statistical information3/. These reports have dealt with distribution, causes, and costs and related phases of accidents for various and collective divisions of the petroleum industry in several sections of the country. This type of study aids the personnel of the Bureau in planning the course of its activities in accident-prevention work and gives useful data to persons engaged or interested in the promotion of safety in the petroleum industry, which will aid them in their efforts to reduce the number and severity of accidents. A majority of petroleum operators and ?service" contractors have acknowledged their responsibility to provide their employees with safe working conditions and to their stockholders for greater economic value of invested capital by establishing safety divisions within their respective organizations. Such divisions have a primary duty, namely, to see that properly designed and guarded machinery and working equipment are furnished the employees and that they are trained in the safest practical methods of performing their work. Some companies and individual operators, however, have shown little or

Jan 1, 1939

By Paul Averitt

The coal-bearing rocks in Iowa occur in an arcuate belt across the central and southern parts of the State (fig. 1) at the northern end of the Western Interior coal field. Coal beds of minable thickness are sporadic throughout this area and are mined principally in the three districts indicated by dark shading on the index map, although coal occurs also in the areas indicated by light shading. The coal is mostly of high-volatile C bituminous rank in all parts of the State. SURFACE FEATURES The coal-bearing rocks in Iowa are concealed for the most part by a covering of glacial drift ranging in thickness from a few feet to several hundred feet. This covering has been dissected to form a gently rolling upland, rising from an elevation of 466 feet at the mouth of the Des Moines River to about 1,200 feet in Calhoun County in the central part of the State. The local relief, however, rarely exceeds 150 to 200 feet.

Jan 1, 1949

By A van Jaarsveld

Environmentally-friendly, safe and cost-effective technology for stope drilling has successfully been introduced at TauTona mine. It has enabled the problem of inadequate compressed air pressure and its downgrading impact on production capability to be overcome. The paper traces the development process which culminated in the conversion of the entire stoping operation at TauTona to electric drilling. Background work which took place at other mines is also described. Statistics of performance improvements are provided. 1. Introduction Holman?s Silver series and the Seco S215 were drills that had a measurable impact on the South African gold mining industry. It is too soon to say whether Hilti will join those great names. However, there is no doubt that the introduction of electric drills into the harsh and unforgiving world of deep level gold mining is a significant development. History has shown that being the first to enter a new technology is no guarantee of long-term success. The pain and suffering which accompany the birth of anything new can deplete the energy of the innovator while at the same time creating opportunities for competitors to leapfrog him. In addition to commitment and enthusiasm, the innovator must therefore also possess, or have access to stamina and resourcefulness to overcome the unexpected difficulties which will inevitably arise. All of these were needed for the Hilti project.

Jan 1, 2008

By Sheridan J. Rodgers

Toxic fumes generated during shot firing under actual mining conditions were measured. Eight shots with Gelodyn-2X and seven shots with Tovex-100 4VT were monitored. Average CO values for Gelodyn-2X and Tovex-100 4VT were 0.20 ft3/lb and 0.09 ft3/lb, respectively. Average N0x values for Gelodyn-2X and Tovex-100 4VT were 0.049 ft3/lb and 0.026 ft3/lb, respectively. The results obtained with these in-mine tests will be used by the U.S. Bureau of Mines in the development of a large chamber method of measuring fumes from shotfiring of explosives.

Jan 1, 1977

By R. J. Forzatti

The production of sulphuric acid from sulphur generates heat. The majority of this heat is recovered as steam and is often used to generate electricity. Heat not recovered as steam is rejected to cooling water systems. The design of the turbine, condenser, and cooling water systems impacts the overall water, energy, and environmental footprint of the plant. This review considers a conceptual 2000 t/d sulphuric acid plant with several alternative cooling water systems. The review utilizes Hatch?s 4 Quadrant sustainable design tool to compare the alternatives on both an economic and a weighted sustainability scale.

Jan 1, 2014

By C. W. Davis

This paper is the second of a series of progress reports on a study, of the hydrometallurgy of manganese which is being conducted in an endeavor to make possible utilization of the large deposits of low-grade domestic manganese ores that occur in several States. There are at least four processes in which a knowledge of the action of SO2 gas on manganese oxides at elevated temperatures may prove of value. One ,of these involves dissolution of manganese from ores. The Bureau of Mines has investigated the hydrometallurgy of manganese by a process in which SO2 gas, a waste product at many smelters, is passed into water to form a solvent for manganese. Although Several manganese minerals acre readily dissolved, rhodochrosite (MnCO3) was attacked but superficially.§. Recent experiments have shown that a roast at 650 to 900°C converts the manganese of rhodochrosite to a form that is quickly dissolved by a weak SO2 solution. Introduction of smelter gases containing as much as 5 per cent SO2 during such a roast would not add much to the cost of the operation and might result in the formation of considerable water-soluble manganese sulphate.

Jan 1, 1930

By R. V. Ramani

This report is volume 2 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation, and ventilation. This volume of the final report describes the Geology and Reserves subsystem of the Master Design Simulator. The two functions of this subsystem are: 1) the design of a geological data library to provide input to the other subsystems of the simulator; and 2) the calculation of coal reserves and associated values and grades under various user-specified conditions. The subsystem uses a weighted moving average method to interpolate between the borehole values, and provides output in report format, graphical plots and/or storage on magnetic tape or other storage devices for later retrieval. The application of the subsystem as an independent model with test results and comparisons with other methods of computing reserves is also presented. The appendix comprises a users manual for the model, and includes a program listing.

Jan 1, 1974

Optimizing production scheduling in open pit mines is important for managing cash flows of mining operations. This paper describes a new, probabilistic, mixed integer programming (MIP) formulation which has been developed to minimize the risk of not achieving planned production targets, in terms of metal production and ore tonnage feed for the mill during production, while considering maximization of total discounted economic value. The new MIP model also recognizes that to minimize movement of excavators over long distances and accommodate equipment access, the blocks scheduled for mining within a period cannot be spread too widely. The model is applied to a laterite nickel-cobalt deposit, as an example of multi-element deposits that have complex ore quality constraints. The results show that the proposed model generates feasible schedules. When compared with traditional optimization techniques, the new model is superior in terms of minimizing the risk of not meeting production targets, especially at the early stages of production, and in terms of generating practical scheduling patterns.

Jan 1, 2006