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By John J. Dran

Large mining companies use a number of sophisticated analytical techniques for introducing the element of risk into the valuation of mineral reserve sites. These methods include, but are not limited to, sensitivity analysis, computer simulation, conditional probability, and portfolio theory. Such techniques enable the managements of these large companies to have an awareness of the many possible ramifications of their investment decisions. On the other hand, small mining companies and individuals in the mining business, due to limited financial and technical resources, still rely primarily on single point estimates of the value of mineral reserves. These small miners introduce the aspect of risk only through the application of an appropriate "speculative" discount rate. This paper illustrates the application of a technique for the introduction of risk into investment analysis. The method appears to be most suitable for use by small mining companies and individuals contemplating a large investment in a new mineral reserve site.

Jan 1, 1974

By J. P. Remi Proulx, Areli Rodriguez, Ruilin Yang

Historically, presplitting has been considered effective in reducing the impact of blast vibrations on highwalls. However, it remains a debated topic: how significantly can it protect highwalls, and is it worth the cost and effort to implement presplit blasting techniques? In hard rock, presplit blasting can leave half-barrels on the highwalls, clearly demonstrating its usefulness. However, in a fractured rock mass, the half-barrels from presplit blasting may not appear in most cases, leading to questions about its role in protecting highwalls. Previous studies in the literature used geophones to measure blast vibrations at far distances and could not ascertain the significant benefit of presplit blasting in reducing the impact of blast vibrations on highwalls. Additionally, no studies in the literature address the role of presplitting in alleviating blasting-released gas pressure that could penetrate joints and open new fractures in highwalls. Yang & Proulx (2019) and Yang et al. (2022) using near-field blast vibration monitoring of signature hole blasts have revealed that the peak particle velocity (PPV) of blast vibrations at a scaled distance of 1 m/kg^0.5 can be reduced by 50% or more for presplit-filtered vibrations. These results have been confirmed for both hard rock and fractured ground. In addition to summarizing the reduction in blast vibrations due to presplitting for both hard rock and a fractured rock mass, this paper demonstrates the relief of subsequent blasting gases after the detonation of blastholes. This is shown through video recordings of gas ejections from a row of empty previously fired presplit blastholes located 6 to 9 meters away from the detonation edge or final buffer row of a blasthole pattern. The results clearly show that presplitting not only lowers blast vibration PPV’s but also reduces the entry of the gases produced by the detonation process into rock fractures and or open joints.

Jan 21, 2025

By Jodi Banta

In an effort to reverse the trend of declining enrollments to mining engineering programs that began in 2015, the University of Arizona has implemented a number of interventions over the past five years, including ramping up its pre-college mining education and outreach, and undertaking several enrollment research projects. This article is the second of two installments to discuss the results of our latest study. The first part can be found in the September 2025 issue of Mining Engineering magazine. To better understand mining’s competitive position, the School of Mining Engineering and Mineral Resources conducted a comprehensive study to determine: 1. How prospective college students, parents and educators perceive the industry, related careers and the mining engineering degree. 2. Factors affecting students’ choices of degrees and career plans. 3. The roles parents and educators play and how they influence students.

Nov 1, 2025

By Peter Riba

Up until ten years ago the industry had arrived at a relatively conventional, and consistent design of coke ovens. Through the years the designers and builders were not being heavily taxed to come up with revolutionary new designs. However, the stimulus for design change was ever present. These stimuli for change are quite important and they are the driving force which produce improvements. The most obvious stimulus to change a design is commercial. To "build a better mouse trap and the world will beat a path to your door" is the well used cliche which best befits this philosophy. As in all businesses, coke oven designs require that all of the considerations, which affect the cost or the desirability of the design, be optimized. One way to increase the desirability of the particular design, 1s to make the design in- expensive to operate. Or, put another way, to increase production for the same operating cost

Jan 1, 1980

By Phillip R. Moyle

A basic precept in mineral exploration is that the best places to prospect are where minerals have already been found. The California desert has many old mining districts once thought to be "played out" that are currently producing more mineral wealth than at any time in the past. Because no "crystal ball" exists that will enable us to predict the Nation's future mineral needs, land management plans must be flexible enough to respond to these often unforeseen needs. MANAGEMENT ISSUES The California Desert Conservation Area (CDCA) (figure 1) encompasses 25 minion acres, nearly one-quarter of the total area of California. Passage of the Federal Land Policy and Management Act of 1976 (FLPMA) launched an intensive program by the Bureau of Land Management (BLM) to study this vast area. Painstaking scientific investigations were made of wildlife and plant populations, soil, air, and mineral resources, range use, and wilderness characteristics, among other environmental concerns.

Jan 1, 1992

By W. R. McDonald

The U.S. Department of the Interior, Bureau of Mines, conducted field tests on acidic copper tailing as part of its program to devise, improve, and demonstrate technology for stabilizing mining and mineral processing wastes. Results will be presented from successful 1/8-acre and 1-1/2-acre demonstration revegetation plots established in 1973 and 1974 on an abandoned copper tailing pond located on public land adjacent to Holden Village, Wash. The tailing was neutralized with treatments of either dolomitic lime or limerock and fertilized with processed sewage sludge and/or commercial fertilizer. Plant growth covering 60 percent of the surface was achieved on both test plots. Regar brome, Tegmar intermediate wheatgrass, and tall wheatgrass provided the best plant growth and surface coverage. In neutralizing the tailing, the target pH of 6.8 was not achieved; however, good plant growth occurred in areas where the pH ranged from 2.9 to 5.8.

Jan 1, 1979

By Kenneth N. Han

Thermodynamic and kinetic aspects of nickel and cobalt leaching from metals. minerals and ores in various media have been reviewed and discussed in this paper. A kinetic model developed to delineate the leaching mechanisms for these metals has been discussed in view of experimental observations. The current review also includes the dissolution behavior of nickel and cobalt from various minerals such as oxides, sulrides. ocean floor manganese nodules, and laterites. A particular emphasis has been extended to similarities and differences of the dissolution behavior of these two metals in various media. The leaching of nickel as well as cobalt metal in acidic solutions and arnmoniacal solutions exhibits in most part mass transfer controlling. although at some pH's, chemical controlling or mixed controlling mechanisms seem to prevail. The leaching of nickel and cobalt from oxides in acids and ammoniacal solutions. on the other hand, can be described best by chemical controlling mechanisms.

Jan 1, 1993

By Edward J. Sterne

Several shale-hosted Pb-Zn-Ag deposits have been discovered in the northwestern Brooks Range, Alaska. Best known among these are the Red Dog, Drenchwater Creek, Lik, Ferric Creek, Hot Dog Creek, and Competition Creek deposits. They occur in a tectonically disturbed sequence of of Mississippian to Triassic shales, argillites, and cherts, and most are spatially associated with volcanic rocks. The sulfides are hosted in shales as disseminations, banded layers, massive lenses, and crosscutting veins. Detailed geologic descriptions of sulfide prospects in the Brooks Range were given by Tailleur (1970), Nokleberg and Winkler (1978), and Plahuta and Robinson (1979). Lange et al. (1980) discussed the formation of the deposits, the nature of the mineralizing solutions, and the temperature of formation on the basis of sulfur isotope studies. More recently, Harrover et al. (1982) detected a correlation between sulfide mineralization and high-temperature formation of charts associated with the sulfides by oxygen Isotope and chert crystallite size determinations.

Jan 1, 2013

By W. G. Prast

Best known for its extensive bauxite and alumina exports, Jamaica also has a small but active industrial minerals sector. The island has for many years been a net exporter of small tonnages of gypsum, metallurgical-grade limestone and marble products. As bauxite and alumina earnings have declined the government of Jamaica has made extra efforts to promote growth of overseas sales of these nonmetallics. The nearby U.S. market is a natural first choice for new exports. Overview In 1984, Jamaica quarried an estimated 3.2 million cu m of marble and fill and an additional 3.5 million cu m of sand and gravel, for use in domestic construction. These amounts are in line with the production in earlier years of the 1980s but are not a factor in the export pattern and need not be considered further. Similarly, annual production of 15 million ton of silica sand for the manufacture of glass bottles is principally consumed by the domestic market.

Jan 1, 1986

The Bureau of Mines conducted a field study of respirable dust concentrations at an underground room-and-pillar oil shale mine and at the aboveground milling facility to determine the dust generation sources, personal respirable exposure, characteristic minerals, and size distribution of the dust. Major dust sources in the mine were the scaling and blasthole drilling operations, and major dust sources in the processing mill were the screening and crushing operations. Principal minerals found in the airborne respirable dust were albite, analcite, calcite, dolomite, quartz, and orthoclase. The average alpha-quartz content of mine and mill respirable dust samples was 4.1 pct and 15.5 pct, respectively. Carbonaceous material such as diesel particulate accounted for approximately 75 pct of the respirable particulate found in the mine. The average coefficient of variance of respirable dust concentrations measured with approved personal dust samplers in the mine and mill was 7.6 pct, the best precision observed to date with the personal dust sampler operated in the field.

Jan 1, 1977

By A Halim

The European Union (EU) have recently issued new Threshold Limit Value-Time Weighted Average (TLV-TWA) for diesel exhaust contaminants, which are CO, NO2 and DPM. The new limits for CO and NO2 were issued in 2017 whilst the one for DPM was issued in 2019. However, in order to allow EU mines to formulate strategies to comply with these new limits, the EU granted a transition period in which mines could use the old limits until the new limits are enforced. The new limit for CO and NO2 will be enforced from 21 August 2023 whilst the one for DPM will be enforced from 21 February 2026. The new limit for NO2 and DPM is very low, 0.5 ppm for NO2 and 0.05 mg/m3 of Elemental Carbon (EC) for DPM. Combination of these two limits would be the lowest among all mining jurisdictions worldwide. It poses a huge compliance challenge to EU mines if they keep using diesel machines. Therefore, a study and a field trial were carried out by the author in 2019–2021 to investigate whether replacing diesel machines with Battery Electric Vehicles (BEVs) would be the best answer to this challenge. This paper outlines results of this study and field trial.

Oct 12, 2022

By K G. van den Boogaart, S Konsulke, R Tolosana Delgado

Adaptive mineral processing has to rely on spatially predicted information on primary geometallurgical parameters, like phase composition, size and shape distributions of grains from various phases, portions of value elements in different grain types. Naively, one would predict these parameters geostatistically and select an optimal processing for the predicted structure. This is suboptimal, due to various kinds of non-linearities in the problem. First, some primary geometallurgical quantities themselves are measured in non-real scales, like compositional or stereologically distorted geometric information. Standard geostatistics has to be replaced by compositional and geometric geostatistics, involving complex transforms and restrictions. Further, only partial and uncertain information is available, introducing a stochastic character to the optimisation problem. Moreover, many response variables leading to costs, outcomes and eventual effects of later processing depend non-linearly on the primary geometallurgical parameters, which implies that the final monetary value is not estimated unbiasedly by kriging. Finally unbiased linear prediction (such as kriging) is not the best method of prediction for decision making. The conditional expectation of the monetary values is needed instead. The impact of these problems is explained in this paper, with simplified examples, and a first approach to a general solution is proposed. CITATION:van den Boogaart, K G, Konsulke, S and Tolosana Delgado, R, 2013. Non-linear geostatistics for geometallurgical optimisation, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 253-258 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Herbert Cremer

The United States,-the largest nickel consumer in the world, produces virtually no nickel from domestic ores. Dependence upon outside nickel - sources and increasing strategic, importance of nickel focused the attention of the United States on deposits within its boundries. The most likely domestic sources of nickel are low-grade oxide and silicate deposits, such as the Cle Clum deposit, Kittitas County, Wash., and the Riddle deposit, Douglas County, Oreg. The Federal Bureau of Mines, Northwest Electrodevelopment Laboratory, Albany, Oreg. has been investigating electric smelting of low-grade oxide and silicate nickel ores. These smelting studies have been on selective reduction to produce low-carbon ferronickel. Selective reduction is based upon the relative reducibility of: nickel, iron, and chromium, in the order named, when the charge contains insufficient carbon or other reductants to reduce the entire quantity of these metals present in the ore.

Jan 1, 1954

By Karl J. C. Harries

"6.1. INTRODUCTIONThis chapter comments on some of the more common types of agreements related to property examination and acquisition, other than the farm-in/joint venture agreement or common undertaking, which is dealt with in the next two chapters. Many of the comments made in Part IV of Chapter 4 apply equally to any such agreement. In addition, many of the comments in Chapter 8 and the examples in Volume II are most certainly relevant to many other types of agreement.6.2. RIGHTS OF FIRST REFUSAL1A right of first refusal is a right that obligates an owner to offer his property, or an interest therein, to the holder of the first right if the owner intends to sell or otherwise dispose of it. It may be triggered either by the owner wishing to offer his property for sale or by receipt of a bona fide offer to purchase his interest from an “outside” third party. The mechanics and procedures to implement a first right should be set out clearly in the agreement, and their basics are the same, whether the first right is a stand-alone document or is part of an acquisition agreement.2Rights of first refusal are common in agreements to permit some control over the disposition of an interest and there they can be a valuable provision. However, some explorationists feel that they are also a good stand-alone agreement to have while a property is being evaluated to decide whether or not it is worth optioning. The reasoning is that such an arrangement will tie up the property to allow a quick look and, if the property looks interesting, the balance of the term of the first right will give an ample exclusive period of time to negotiate with the owner and settle an acquisition agreement. In addition, the explorationist is protected by the first right if the owner decides to negotiate a deal with another party."

Jan 1, 2003

By Alfred W. G. Wilson

In this paper is presented a review of the changes that have taken place in certain Canadian non-metallic mineral industries since 1909. The fifteen-year period 1909 to 1923, inclusive, has been selected for two reasons. In the first place, statistical treatment of the subject under review has been nearly uniform throughout the period. In the second place, this decade and a half is itself further subdivisible into three well marked quinquennial periods, the middle one covering the period of the great war when industrial conditions were greatly disturbed. It then becomes possible to institute certain comparisons between equal periods before and after the war disturbances. The items selected for inclusion in this review are certain of the more important members of that class of minerals usually grouped together under the heading of non-metallics. They are all minerals of which Canada is known to possess important resources, and which are indispensable to many of our greatest manufacturing industries.

Jan 1, 1925

By M. Pearson, J. Irvine, L. Mercer, P. Lauzon

Severe service ball valve performance has a direct impact on the mechanical availability of high pressure oxidation and leach plants. The primary function of these valves is to isolate the autoclave for maintenance. Valve failure has historically contributed significantly to the maintenance downtime of these process plants. An understanding of the root causes of valve failures is the first step in increasing the reliability of the severe service ball valves. A rigorous failure analysis practice has been developed by Hatch for investigating refractory failures in furnaces and kilns based on Kepner-Tregoe methodology. The method has also been modified for valve failure analysis. From a root-cause failure tree analysis of each of the valve components, a list of all potential valve failure mechanisms was developed for ranking and evaluation, along with recommendations for further valve development. The purpose of this paper is to present the reader with the modified Kepner-Tregoe method and examples of this analysis.

Jan 1, 2004

By Launa G. Mallett, Charles Vaught, Dana C. Reinke, Lisa J. Steiner, Lynn L. Rethi, Kathleen M. Kowalski-Trakofler, Jr. Brnich, William J. Wiehagen

Safety and health professionals recognize that training is a critical element of any effective safety and health program. An extensive literature survey has led the authors to conclude that we are at the beginning of a revolution in training due to changes in the demographics of the workforce, the rapid growth of technology, and the universal ascendance of the information age. Of present major concern in the mining industry is how to provide appropriate training for an aging workforce and concurrently develop training for the expected influx of new and less experienced miners as older workers retire. This report explores the key issues in the changing safety and health training area as identified by the multidisciplinary team of NIOSH researchers who conducted the literature survey. Issues include generational differences between newer mine workers and the present workforce with respect to their physical, psychological, social, and cultural characteristics; their learning styles and work expectations; and the impact of technology. Some preliminary conclusions are offered for future training needs.

Jul 1, 2004

By W. Noel O?Brien

Introduction Since 1930 numerous improvements have been made in equipment designed for the mechanical removal of broken ore in underground mining operations. New applications of mechanical equipment, as? well as improvements and adaptations of well established systems, are being made continually. It is the purpose of this paper to discuss present-day equipment for the removal or transfer of broken ore by means of a powered hoist and scraper arrangement. The terms used throughout the paper are those commonly employed in the trade literature and by mining men. The terms slusher hoist, hoist, and scraper hoist are used inter-changeably to mean a machine, powered by compressed air or electricity, with drums for the winding of wire rope. The tail rope, also known as the pull-back rope or return rope, drags the empty scraper toward the tail-sheave, that is, back to the loading point. No attempt is made to cover the entire field of application of scraping methods. Rather it is the? writer's desire to emphasize the fundamental principles of scraping practice and design and to relate them to some modern applications. The available literature on scraping practice has been freely used. together with personal observation and information and advice of practising engineers and representatives of companies manufacturing slushing equipment.

Jan 1, 1951

By D. Johann, E. Zanetti, I. A. S. Brum, P. M. Zancan, A. F. Castro

"This study was done from a sample of coal mined at the Vale-Mozambique mine, located in Moatize district, Tete Province. The aim of this work is to analyze the reagent system in the flotation of coal fines belonging to the Upper Chipanga layer (UC). Among coal processing methods, flotation stands out as one of the most important for the concentration of this material, in particular in the treatment of fine particles. The total feed of the Vale-Mozambique processing plant is 8,000 tph of coal, where 10% of this feed corresponds to the fine fraction that feeds the flotation circuit. The material used in this study had a particle size of 96% smaller than 0.25 mm. The reagents used in the flotation tests were betacol and diesel oil as hydrophobizing agents and MIBC as frother. The range of betacol concentrations in the first test phase was 200 g/t to 500 g/t, and in the second phase 200g /t to 500g /t while diesel oil and MIBC were kept constant at 300 g/t. The immediate analysis followed the Brazilian standards NBR 8289, NBR 8293, NBR 8290; and NBR 8299. The results showed that it is possible, from a feed with ash content around 22.84%, to obtain products with levels below of 10% ash, with a mass recovery around 50%. The recovery of carbonaceous matter was also evaluated and presented positive results. Complementing this study, the effect of H2O recovery was evaluated and it was observed that for the concentrations of betacol the recoveries ranged from 6 to 9%, and for diesel oil plus MIBC were 4 to 7%.INTRODUCTION Considering the increase in population and energy consumption as humanity has been living along the last decades and the consequent demand for non-renewable natural resources, it is clear the challenge of the mineral industry in the search for new technologies and improvement of the existing ones. This challenge is justified by the need for better industrial results and to meet the market specifications, taking into account the reduction of deposits with higher contents and the need for beneficiation of more complex ores, lower levels and lower release granulometry. Usually in these situations, processes already well-established as the gravimetric (Sampaio and Tavares, 2005) have not good results."

Jan 1, 2018

By Kenneth M. Haley

THE development of Reserve Mining Company's pelletizing practices began in 1949 in a pilot plant located at Ashland, Kentucky. Three years later the participating companies -Armco Steel Corporation, Cleveland Cliffs Iron Mining Company and Republic Steel Corporation concluded the work and the small plant was shut down. Oglebay Norton and Company was the operating manager and Armco Steel Corporation furnished labor and services. Arthur G. McKee and Company were the designers and constructors. The equipment flow sheet that was employed in that pilot operation is shown in Figure 1. This was Reserve's first step from the laboratory work per-formed by the Mines Experiment Station of the University of Minnesota in developing a commercial operation. The plant used New York state concentrate, purchased from Jones and Laughlin Steel Corporation's Benson Mine. This concentrate, minus 14 mesh, 64.3 per cent Fe, 5.7 per cent Si02, was processed at Ashland to 80 per cent minus 325 mesh in conventional ball mill, classifier, thickener, filtering

Jan 1, 1961