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By William J. Bryson

Just picture, if you will, the hot, lonely and desolate Ochre Mountains west of Salt Lake City. There works a grizzled old miner, his boots worn down, his clothes hang on a body stooped by years of hard labor. His skin is wrinkled and leather toughened by many years in the hot desert sun. His ever faithful burro stands patiently in the shade of a large rock as the tired old miner examines ore samples just acquired that very morning. Suddenly the old man's eyes widen, his breathing becomes rapid. 'Leaping to his feet, with a gleam in his eye, he cries, "Eureka, I'm rich, I've found the mother lode. This is where I will start my digging. " Without warning, the silent wilderness is alive with wild, shouting, charging figures! Frightened the old miner glances about him wide-eyed and pan- icky. His heart sinks, dismayed he now knows all is lost, this is the end. For there leaping from behind rocks and brush papers in hand, are the men from the Department of Interior, Bureau of Land Management, State Mine Inspectors, OSHA, MESA, EPA, OEO, and the never ending list of regulatory bodies related to todays mining industry.

Jan 1, 1975

By D. J. Benton, S. Finley, D. T. Orr, A. J. Chambers, M. A. Stepan

"Corrosion of ground support can lead to falls of ground that pose a significant risk to miner safety. To address this problem, the National Institute for Occupational Safety and Health (NIOSH) is investigating corrosion at the Hecla Mining Company’s Greens Creek Mine, located near Juneau, Alaska, USA. Field studies have used photogrammetry surveys to document welded-wire mesh corrosion, and laboratory studies at NIOSH’s Spokane Mining Research Division (SMRD) have investigated the effects of corrosion on ground support integrity. Findings show that (1) corrosion monitoring through photogrammetric methods may be effective for qualitative measurements of welded-wire mesh corrosion, and (2) there is a relationship between loss of load-bearing capacity and the diameter loss due to corrosion in welded-wire mesh. Photogrammetry results thus far have measured an apparent bulking of the corroded welded-wire mesh, and preliminary laboratory tests have investigated the relationship between the larger bulked and effective wire diameter. If this relationship is verified, these results may indicate that photogrammetry, when combined with the models produced in laboratory tests, could offer a means of monitoring corrosion levels, as well as rock rib deformation. INTRODUCTION Reducing the number of rock fall injuries and fatalities is an important part of the mission of the National Institute for Occupational Safety and Health (NIOSH) Spokane Mining Research Division (SMRD). Ground control using support systems to protect miners from rock falls is one of the oldest mining sciences, and considerable research has led to a variety of modern tools and methods in use today. Among these tools are rock bolts and welded-wire mesh, which are made from increasingly higher-strength steel grades to meet the increasingly demanding requirements of underground mines [1]. However, the benefits of these higher-quality support elements may be negated in corrosive mining environments. A better understanding of how corrosion affects the support capacity of ground support systems will assist engineers in determining when an opening is at a greater risk of falls of ground. Accelerated corrosion has been occurring in some areas of the Hecla Mining Company’s Greens Creek Mine near Juneau, Alaska, USA. Corrosion of ground support has resulted in two falls of ground occurring between April 2015 and March 2016. While these falls of ground did not injure any personnel, mine management recognized the high risk to miner safety and responded by actively undertaking a ground support rehabilitation program. Rehabilitation measures include the installation of both galvanized and coated, corrosion-resistant bolts and welded-wire mesh, depending on local conditions."

Jan 1, 2017

By Jerzy F. Sobala

Large - scale tests at the Polish Safety in Mines Institute /established in 1925 as "Barbara" Experimental mine/ performed in underground and surface experimental galleries, simulating conditions in roadways in mines, are the basic source of knowledge about development and propagation of explosions. Investigations up to 1973 were performed under the Institute's former research director Professor W.B. Cybulski s supervision, whose handbook concerning combating of coal dust explosions in collieries has been also published in the U.S. (2), and are continued until now. For investigating explosions the "Barbara" Mine disposes of 170 m /7.5 sq m/, 200 m /5 sq m/ and 400 m /7.5 sq m/ underground gallieries as well as of 10 m, 25 m, 44 m and 100 m surface galleries. For example, in the 200 m gallery more than 5200, and in the 400 m gallery - more than 2200 test explosions have been performed. Basing on determination of explosion hazard in roadways in collieries and on data of scientific research performed at the Safety in Mines Institute, the strategy of combating the explosion hazard in mines was elaborated; it includes mainly diminishing of coal duet. deposition in roadways, and -because of the possible inefficiency of this safety means in some roadways in mechanized collieries -- the introduction of three additional defence lines against coal dust explosions. It should be mentioned that at the "Barbara" Mine the problem of coal dust explosion initiation was elaborated as contract work for the U.S. Bureau of Mines. The main aim of this paper is to discuss some aspects of methods and measures for combating coal dust explosion hazard in highly mechanized mines in the Polish mining industry where in some roadways explosible coal dust is present, but it is not the aim to evaluate the effectiveness of methods and measures for diminishing the make-up of coal dust and coal dust deposition rates in roadways.

Jan 1, 1980

By K. Sasaki, T. Murakami, S. Akibayashi, Q. Wei

A numerical analysis and an experiment were done on groundwater flow past a bore hole with a cylindrical obstacle at its center. Flow around the obstacle in the bore hole was studied in detail. Two dimensional governing equations to simulate this flow were written for the hydraulic head and seepage velocity in a porous medium and for the vorticity, stream function, and velocity in the bore hole. These equations were non-dimensionalized and solved by using the alternating direction implicit and successive-over-relaxation finite difference methods. Flow visualization experiments and velocity measurements in the bore hole were done with a two dimensional model composed of a porous medium. The numerical analysis procedures were validated by a comparison of numerical and experimental results. Effects of the Reynolds number and obstacle size on flow in the bore hole are clearly shown in the velocity and streamline profiles. The quantitative relation between the seepage velocity in the porous medium and the velocity of flow around the obstacle in the bore hole also were estimated.

Jan 1, 1996

By K. L. Browne

After a decade of high copper prices, major mining companies are renewing their interest in purchasing operating properties and/or developing ore bodies. An existing operation carries with it a history that can present unique opportunities, while a greenfield operation allows for the establishment of a defined culture. Capital investments are distinctly different. A comparison of BHP Copper's Robinson operation, a greenfield property, and BHP Copper's Tintaya operation, a government owned Peruvian property, will provide insights into mining, concentrating and cultural differences between North and South America operations. The Broken Hill Proprietary Co. Ltd. (BHP) is Australia's second-largest company. Fiscal year 1996 sales were US$16 billion, profits were more than US$1 billion and total market capitalization was about US25 billion. In 1885, BHP began mining silver, lead and zinc at Broken Hill, New South Wales, Australia. Throughout its 112-year history, BHP achieved an impressive record of performance and expansion. Today, BHP is one of the world's leading companies (66th on the Standard and Poors 500), having diversified into steel, petroleum and mining with more than 65,000 employees in 70 countries.

Jan 1, 1997

By E. A. Metz

It has been approximately four years since the International Agency for Research on Cancer (IARC) reclassified crystalline silica as a "group one" substance. Since then, crystalline silica has been considered a human carcinogen. Silicosis is a preventable disease, and several aggressive campaigns have been developed to increase awareness of silica-dust-related problems in the industrial environment. New analytical techniques are now being developed to determine quantitatively the amount of crystalline silica in materials. Yet, still much is to be learned about the surface properties of silica and the way in which the disease progresses into full-blown silicosis. This paper discusses the interaction of free radicals generated by the mineral particles and lung tissue. It is the cell injury and DNA damage that progresses to fibrogenesis. Freshly fractured surfaces of silica contain free radicals. These free radicals play an important role in the stimulation of the alveolar macrophage and the development of the inflammatory reactions leading to the fibrotic response caused by silica. Engineers, scientists and physicians need to discuss the mineralogy of silica and the technical issues concerning the development of silicosis.

Jan 1, 2000

By B. A. Firth

Australia is the largest exporter of coking and thermal coal to the international market. This market has required that the coal being presented to the customer has a particular level and consistency of quality. In this context, the Australian industry has developed coal preparation practices that allow this criteria to be met while maximising the recovery of coal from the resource. This has required on- going developments in both coarse and fine coal cleaning technology over the past 30 years. Coal flotation has undergone a number of developments with regard to maximising recovery from the overall plant circuit. This includes innovative flotation circuits (split feed), methods of enhancing the use of reagents and control of pH. During the 1990s, there have been major changes in flotation as practised in Australian coal preparation plants. Columns have become the preferred technology for both greenfield developments and plant upgrades. This paper will outline the above developments with a number of plant examples and the reasoning that has driven the change. The ongoing research that is being carried out on new cells to optimise the overall fine coal circuit will also be discussed.

Jan 1, 1999

By III Kimball

Mining wastes have received individual attention under the Resource Conservation and Recovery Act (RCRA) since its inception, in recognition of the special characteristics that distinguish mining wastes from other solid wastes. The Environmental Protection Agency (EPA) has recognized that: - Mining wastes are generated in much larger volumes than other industrial wastes. Most material handled in mining is waste (over 99% in many cases) and not marketable product, whereas waste is a small portion of raw materials used in most industries. Consequently, controls used for hazardous wastes may be technically infeasible or economically impractical. - Nearly all mining waste is managed at the site of generation and is land-disposed. . - Mining wastes typically pose lower hazards than other industrial wastes. Mining operations are located predominantly in sparsely populated areas and in arid or semi-arid areas with little surface water runoff and deeper water tables.

Jan 1, 1990

By A. de Ferran

Is the Brazilian gold rush over? Judging from the situation in Brazil over the past few decades, the answer is almost certainly yes. The picture of swarms of Brazilian prospectors or "Garimpeiros" crowding or, more correctly, overcrowding the gold regions of the Amazon jungle using the time-aged empirical approach to gold exploration has finally run its course. There are two fallacies that have lead to a reduction in the discovery of new gold fields in Brazil. The first fallacy is that "Brazil's geology is largely unknown." The extreme depth of weathering and the general lack of understanding of the shield deposits are at the origin of this misconception. The second fallacy is that "Brazilian prospectors ("garimpeiros") are very naive, have very little technical knowledge and can only produce gold at very low recovery rates." This is more of a result of wishful thinking for the purpose of justifying limiting exploration programs than it is a real consideration. In this paper, the author takes a methodical heuristic approach to gold exploration in Brazil and offers this as an alternative to the empirical approach of the garimpeiros.

Jan 1, 1998

Early experiences suggested autogenous mills were difficult to operate and consumed substantially more energy than conventional rod/ball mill circuits. As our understanding has increased and the technology has matured this perception has changed to the point where most new comminution circuits are ag/sag based. In addition many operators have replaced existing conventional circuits with this technology. The JKMRC has been studying ag/sag mills for over 20 years. During this time it has amassed what is probably the single largest and most detailed data base of pilot and full scale mill operations in the world. This has been used to help develop and refine its cur- rent commercially available mathematical model of ag/sag mills. A decade of its application has greatly helped simplify both design and operation of ag/sag milling circuits as well as helping to promote the effective use of recycle crushing, secondary crushing and closed-circuit operation. This paper describes the development of ag and sag milling in terms of our understanding and the evolution of the technology. In addition the application of mathematical modelling and simulation in designing and operating efficient circuits is described with the aid of practical examples.

Jan 1, 1998

By R. Latifovic

Assessment of the possible impact of existing and future mining projects located in remote areas may be difficult and costly. This may have an adverse effect on the process of issuing mine permits and development of new mines. A remote sensing based land cover change assessment methodology presented in this paper is a promising avenue to render this process more meaningful, precise and affordable. It has been applied to a case study of the Oil Sands Mining Development in the north-east of the Canadian province of Alberta. Recently, the Athabasca Oil Sands Region (AOSR) is a place of unprecedented growth of open-pit mining operations. This study was focused on the primary impact onto the landscape and vegetation resulting from exploration and, mining development. This impact was assessed using an information extraction method applied to two LANDSAT scenes. The analysis based on derived land cover maps shows a 8.64% decrease of natural vegetation in the study area (715,094 ha) in 2001 relative to 1992. It is demonstrated that the methodology presented here provides reliable results and is fully applicable for the assessment of the environmental impact of large scale mining operations.

Jan 1, 2006

By Kadri Dagdelen

Production scheduling of an open pit mine is one of the most important steps in open pit mine planning. The production schedule of a mine defines the distribution of cash flows and as a result directly influences the net present value and overall economic feasibility of a project. It is becoming more and more critical to obtain an exploitation schedule of a deposit such that highest possible returns are achieved from a project. As the mining industry mines lower and lower grade ores, production scheduling is becoming a key item which can make or break a project. Although the need to plan and operate a mine with an optimum production schedule has been obvious for some time, the methods used to obtain such a schedule have not been. There is not a single, mathematically proven, optimum mine production scheduling algorithm which is widely accepted and used today. In an attempt to determine a production schedule which is optimum, a new algorithm was developed. This algorithm, in theory, is based on the lagrangian concepts of mathematics and in practice is based on the parameterization concept of mining. This paper describes the fundamentals of this newly developed algorithm.

Jan 1, 1986

By Rubén Pavón] [H.

Mexico, that for various years held the second place among the elemental sulphur producers in the world, now occupies the fourth position. Nevertheless, taking advantage of the recent increase in the international prices of the metalloid, it is expected that Mexico recovers its traditional position producing, for the first time, over two million tons of sulphur during 1974. Drawing from material stockpiled during the last years sales are expected to reach 2.5 million tons, at excellent prices in the foreign markets, but not so in the domestic ones where prices have remained practically static since 1955, in spite of substantial escalation of production costs. Of the two sources of elemental sulphur in Mexico, the frasch process extraction from the salt domes of the Tehuantepec isthmus where the most important reserves are located - is the one that shall have an important increment. An increase of production of lesser magnitude is expected from sour gas, since sulphur recovery plants wilI go on stream toward the end of the year in the new oil fields recently located in the State of Chiapas. Two Mexican corporations are expanding and improving rational Frasch extraction operations. Together with Petroleos Mexicanos' sulphur recovery from sour gas it is estimated that production during 1975 shall reach 2.5 million tons and, consequently, supply the domestic market and generate an important sum of foreign currencies.

Jan 1, 1974

By Connie Travers, Ann Maest, James Kuipers, David Atkins

The science of predicting future water quality at hardrock mine sites has been practiced for at least the past 30 years. As part of the National Environmental Policy Act (NEPA), mines and other industrial facilities in the United States on federal land are required to estimate impacts to the environment, including direct impacts to water quality and indirect impacts that are later in time but still reasonably foreseeable (Kempton and Atkins, 2000; Bolen, 2002). Facilities on private land in the United States may also be subjected to State or federal processes that may or may not require prediction of potential impacts to water resources. Other countries have followed a similar approach, largely based on the requirements of NEPA. A wide array of scientific approaches has been used to predict water quality that could result from construction, proposed expansion, or other action at an industrial facility. In this study, we review the methods and models used to predict water quality at hardrock mine sites, with an emphasis on uncertainties associated with these techniques. Because water quantity and quality are interrelated, methods and models used to predict water quantity will also be discussed, but the emphasis will be on how these methods relate to water quality. This study brings together technical information on water-quality predictions at mine sites in a single paper, and attempts to present a straight-forward approach to using and evaluating the results of the methods and models used to predict water quality at mine sites. Approaches developed primarily in the United States, Canada, and Australia and applied in these countries and in other parts of the world, especially in the last 10 years, are discussed, and the format of the study is geared toward use by regulators of hardrock mines. The approach and results of this study could also be used by environmental managers at mine sites and community groups, and allows for the creation of a checklist for prediction methodology used at mine sites.

Jan 1, 2005

By C. Ceccarini, I. Salvadori, G. Oggiano

GENERAL BACKGROUND The first mention of the presence of bauxite in the mesozoic series of north-west Sardinia (fig. 1) is owed to Oosterbaan, a Dutch geologist, who carried out a geological survey of the area in the ninetten thirties. A more detailed study of the mesozoic series was attempted in the fifties by Pecorini and other, who concentrated particularly upon the stratigraphy of the bauxitic horizons, through examination of the various outcrops. In the sixties a pining company, Monte Amiata S.p.A., turned its attention to a section of the deposit outcropping near Olmedo and, considering it to be of some promise, carried out prospecting works consisting essentially of various trenches, some bore holes, a few adit and a. layout plan for the preparation and execution of trial exploitation. The results, although positive, did not convince the company's shareholders to continue the exploration. This report, which is intended as a new contribution to knowledge of the Sardinian bauxite deposit, takes into account the information acquired not only from a drilling prospection begun in 1979 in connection with the SOMIT-PROGEMISA joint venture, but also the results of structural studies and numerous chemical, mineralogical and

Jan 1, 1984

By A. de Ferran

Is the Brazilian gold rush over? Judging from the situation in Brazil over the past few decades, the answer is almost certainly yes. The picture of swarms of Brazilian prospectors or "Garimpeiros" crowding or, more correctly, overcrowding the gold regions of the Amazon jungle using the time-aged empirical approach to gold exploration has finally run its course. There are two fallacies that have lead to a reduction in the discovery of new gold fields in Brazil. The first fallacy is that "Brazil's geology is largely unknown." The extreme depth of weathering and the general lack of understanding of the shield deposits are at the origin of this misconception. The second fallacy is that "Brazilian prospectors (`garimpeiros') are very naive, have very little technical knowledge and can only produce gold at very low recovery rates." This is more of a result of wishful thinking for the purpose of justifying limiting exploration programs than it is a real consideration. In this paper, the author takes a methodical heuristic approach to gold exploration in Brazil and offers this as an alternative to the empirical approach of the garimpeiros.

Jan 1, 1997

By V. T. McLemore

Rare earth elements (REE) are becoming more important in our society. REE deposits are found throughout NM. Some REE past production (1950s), as bastnaesite, came from the Gallinas Mountains district, Lincoln County, NM. Several companies and the U.S. Bureau of Mines (USBM) have conducted exploration programs to identify REE potential. Four types of deposits are found in the district: epithermal REE-F veins, Cu-REE-F veins, REE-F breccia pipe and iron skarn deposits; all are associated with Tertiary peraluminous, alkaline to alkalic-calcic volcanic rocks. District zonation is defined by base metals (REE-F-Cu veins) that form center of the district, surrounded by REE-F veins. The magmatic-hydrothermal breccia pipe deposits form a belt partially surrounding the veins. Iron skarns formed at the top and edge of the trachyte intrusion and are likely the earliest stage of mineralization. In 1991-1992, USBM calculated an inferred resource of 0.487 million metric tons with a grade of 2.95% total REE. With the projected increase in demand of REE, areas such as the Gallinas Mountains district in New Mexico are being re-examined for additional REE potential.

Jan 1, 2011

By G. Pan

A geostatistical approach is proposed for the design of infill drilling programs. The method consists of the following four major steps: developing geological favorability models, delineating mineralization and ore envelopes, classifying resource potentials, and designing infill drilling patterns. Geological modeling develops the permissible geological zones in which infill drilling is designed. Modeling mineralization and ore envelopes establishes criteria on the potential blocks to be drilled. The blocks that are included within the ore envelopes are considered in the infill drilling. The following four types of resource potentials are used in this analysis: measured, indicated, possible and barren. Blocks in the indicated category are the top targets to be confirmed in infill drilling. Blocks of possible resources may be considered exploration targets. The algorithms involved in the analysis include indicator favorability analysis, indicator kriging and ordinary kriging. A case study on a gold deposit of the Carlin type is presented to demonstrate the methodology. The deposit was originally delineated by a sparse drilling program with about 230ft of average spacing. The infill drilling design, based on the new method, suggests a significant reduction on the number of holes from a regular-grid infill drilling pattern.

Jan 1, 1996

By Robert B. Fulton

The objective of this chapter is to discuss the interrelationship between industrial minerals and chemical manufacturing. It is intended to supplement rather than duplicate the commodity chapters. Particular emphasis is given to the pertinent chemical element and to market factors. Condensing this broad subject into a few pages of this handbook permits treating only the most important elements derived from industrial minerals. Hydrocarbons, which quantitatively dominate as raw materials for the chemical industry, are omitted, as are the metallic elements and the minerals covered in other "use" chapters such as phosphorous, potassium, and nitrogen for fertilizers, and titanium dioxide for pigments. The remaining six elements of major importance are: boron, bromine, chlorine, fluorine, sodium, and sulfur. These elements are treated individually under separate headings. [Table 1] affords an overview of the main industrial minerals, the chemical products derived from them, and end uses of the products. Salt brines have particular importance as raw material sources for the chemical industry. Table 2 is a chart of the chemical compounds derived from four types of brines: (1) Owens Lake-type brines, which are sources of boron and sodium compounds; (2) Midland-type brines, from which bromine, iodine, and chlorides of calcium, magnesium, potassium, and sodium are derived; (3) Searles Lake-type brines, yielding boron, bromine, lithium, magnesium, potassium, and sodium compounds; and (4) Silver Peak- type brines, produced mainly for lithium. MARKET ATTRIBUTES Some of the important market traits common to industrial minerals used by the chemical industry are: 1. They are international commodities, such as fluorspar and sulfur, which largely move to foreign consumers. 2. Grade, and freedom from deleterious elements are important factors affecting their usability in chemical processes. An example is salt (NaCl) used in electrolysis where ultrapure evaporated salt is required to meet rigid specifications. 3. Purified products take on the characteristics of specialty items and command a distinctly higher price than the basic commodity from which they are derived. 4. In practically all cases, chemical users require some sort of cleaning or beneficiation of the naturally-occurring mineral to bring it to specification, and individual specifications may vary from user to user for essentially the same use. 5. In some instances it is necessary to strike a balance between what the vendor can supply and what the buyer requires, with the result that specifications have to be eased to afford the needed materials in marginal cases. 6. Because they tend to be bulk commodities, low cost for handling and transportation are important and such costs may limit the area from which a chemical user can draw his supply. 7. Shipments are usually in bulk and frequently in multiple-car, full-trainload or full-shipload lots to reduce transport costs, which in turn may require large terminal investment facilities. 8. Purchases are generally by contract of one year or longer term, with spot buying playing only a minor role. 9. Contract prices are usually fixed in short term commitments, but may vary according to assay, with premiums and penalties for content above or below the norm; however, general practice is for specifications to be fixed in the contract with minimums being set for the desired material and maximums for undesired elements. In longer term contracts, prices are often escalated on labor, fuel, and other vendor processing costs. 10. Suppliers of individual commodities to the chemical industry tend to be limited in number and are generally medium- to large-size producers that supply a few major consumers. 11. The bulk of the mineral volume is for basic chemical uses, sulfur suppliers to sulfuric acid producers and fluorspar for hydrofluoric acid producers being typical examples. These basic chemical products then are used for the production of other products. 12. Shortage of a supply of adequate quality leads consumers to seek substitutes. In the case of fluorspar, much work is being done on recovery of fluorine from phosphate rock. Success in the form of fluorosilicic acid and/or hydrofluoric acid production could, in time, affect the hydrofluoric acid chemical industry. 13. Markets tend to be characterized by cycles of shortage followed by oversupply, with attendant wide price fluctuations. 14. Baniers to trade can have an adverse effect on the necessary movement of industrial minerals used by the chemical industry in international trade. Antidumping laws, quotas, and tariffs can disrupt or dislocate normal markets. 15. Chemical industry consumers may back-integrate for security of supply or for favorable economics, sometimes by joint ownership and often with experienced mining partners.

Jan 1, 1994

By John T. Awald

The efficiency of search for porphyry copper and molybdenum deposits can be greatly increased. A model exploration system is here presented to show how geologic literature data and field surveys can be aided by modern statistical and computer methods. Assuming that major ore deposits occur in clusters, it is possible to evaluate rapidly large areas at modest cost and with minimum investment risk. An example of the success of these methods is given. Clusters of mine density and metal production covering the State of Nevada were plotted and machine contoured. Selection of a 47,300 square-mile area on the Nevada-California border was made. Within this area, detailed analyses were performed, and a 3000 square-mile site was picked for subsequent field examination. To initiate efficiently the field work, 81 stream sediment geochemical samples were collected and analyzed for copper, zinc, and molybdenum. These data established local variance and necessary statistical controls. Following this, a total of 151 geochemical samples were used to survey the 3000 square-mile area. Computer contouring of results directed attention to specific target areas for detailed geologic analysis, property acquisition and drilling. A total of 22 copper-zinc and molybdenum anomalies were identified. Four of these were recommended for further exploration. To date, two have been acquired and drilled and preliminary ore reserve and financial analysis have been made on one. The estimated cost and time for the regional exploration phases leading to these targets were thirty man-weeks and $16,000.

Jan 1, 1973