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By C. E. Jordan

Abstract. The U.S. Department of the Interior, Bureau of Mines, as part of its effort to maintain an adequate supply of minerals and metals to meet national economic and strategic needs, is conducting research on the pneumatic recovery of coarse mica. A system of crushers, screens, and zigzag air classifiers is used to concentrate coarse liberated mica particles from mica ore and from the waste tailings of abandoned mica operations. The plus 0.21-millimeter-size mica is effectively recovered by this method. The mica concentrates produced contain over 90 percent mica. The method recovered up to 78 percent of the mica in the samples. As a dry concentration method, the pneumatic-beneficiation technique may be advantageous in areas of limited water resource.

Jan 1, 1980

ABB Industrial Systems is one of the largest electrical engineering companies in the world. ABB develops, manufactures and markets electric drives. The company has more than 100 years experience in the application of medium- and high-voltage AC machines. And ABB's continuous research and development program ensures that its machines use the latest technologies and materials. Each motor is custom designed to meet specific applications. The HXR high-efficiency motors (100 to 1,900 kW or 134 to 2,250 hp at 50 Hz) are efficient and have low noise levels. Typical applications are pumps, fans, blowers, compressors and pulverizers. The enclosed units are constructed with external cooling ribs and fans. And the motors are equipped with solid, longlife stators and rigid rotor construction. The patented rotor construction provides for low vibration levels. ABB's large synchronous motors (1 to 50 MW or 1,340 to 70,000 hp up to 900 rpm) are used in the mining industry for crushing, grinding hoisting and conveying systems. These motors are designed to customer's specifications, including existing foundations. They can be equipped with fixed or adjustable speed control.

Jan 1, 1998

By Lloyd W. Trevoy

Commercial production of heavy minerals from plant tailings streams is undergoing study by Syncrude Canada Lrd. When tar sand from an open pit mine is processed and up- graded to synthetic crude oil, heavy minerals can be recovered from the extraction circuit and can be upgraded to provide concentrates of zircon and titanium minerals. The titanium minerals concentrate consisting of a mixture of ilmenite, leucoxene and rutile, could be utilized as recovered or could be upgraded to synthetic rutile. With the construction of further synthetic crude oil plants in Western Canada a large reserve of heavy minerals will become available for utilization.

Jan 1, 1981

By Simon W. Houlding

This paper summarizes recent developments in computer modelling and estimation technology. Significant improvements in computational and modelling efficiencies have advanced technical computing to the stage where, for the first time, it can be realistically applied to short-term mine planning and production control. Real-time interactive grade estimation of complex shapes, volumes and grade distributions, based on immediate turn-around of production sample grades, is now possible. An added benefit is the ability to produce complete geostatistical estimates which include confidence limits. These can be incorporated into the decision making and risk assessment processes of production control. Why the need for new technology? What is wrong with the conventional methods which have sufficed for the last thirty years? The response is manyfold. They suffer from inefficient computational processes and conflicts with geostatistical theory. They are responsible for constricting the flow of information between the disciplines involved in the mine production process. Finally, it is illogical to approximate irregular geological and mining volumes with orthogonal sets of rectangular blocks. Geological materials do not occur in block formation; and mining methods which excavate rectangular blocks have yet to be developed. Other computer based technologies have evolved out of the dark ages of rectangular approximations and have successfully dealt with irregular three-dimensional geometries. It is time for computing in the mining industry to follow this example and take full advantage of available technology. To provide the necessary background, consider the basic requirements for successful implementation of technical computing within the mine production process.

Jan 1, 1992

By Kevin Andrews, Zach Agioutantis

Analysis of Coal Pillar Stability (ACPS) software, released in 2018, integrates numerous empirical pillar design techniques. The ACPS program incorporates methodologies originally available as design tools from the National Institute for Occupational Safety & Health (NIOSH), including Analysis of Longwall Pillar Stability (ALPS), Analysis of Retreat Mining Pillar Stability (ARMPS), Analysis of Multiple Seam Stability (AMSS), and concepts including Coal Mine Roof Rating (CMRR), the Mark-Bieniawski pillar formula, and pressure arch loading. The design methodologies that are the basis of ACPS were developed via analysis of significant amounts of real-world data and have been standards of the United States coal industry for decades. While there are empirical factors built into ACPS, making it ideal for use in U.S. coalfields, the concepts in the program have proven to be applicable in variable mine settings, and the software was developed to allow for user-based, site-specific modifications of key design inputs. Application of ACPS to cases outside the regions for which it was developed must be approached carefully, and continuous development of site-specific data is mandatory. A case study is presented involving the application of ACPS to assess pillar stability and assist future design for an underground lignite mine in Eastern Europe. Assessment of in-mine observations, review of the geology of the lignite mine, and evaluation of specific conditions associated with a failure event resulted in “calibration” of key input factors to ACPS. Scenarios evaluated with ACPS suggest that pillar strength and overburden depth are key factors for the determination of pillar stability and design in future areas.

Jun 25, 2024

By W. P. Blacutt

A financial-economic model incorporating physical, market, and policy variables is developed for mining investment in Bolivia. Additional risk criteria emanating from political instability. new mining legislation, recent environmental regulations, and a new minerals taxation system are accounted for and are integrated into the investment decision model. Results of the model indicate that geologic and market variables have the dominant effect on the investment-worth function. Among policy variables, exchange rate and taxation policies have the most significant influence. Depreciation allowance for infrastructure development has negligible weight in the investment-worth function. The business structure of the firm considering investing in the Bolivian Polymetallic Project is found to be an instrumental factor in the investment-worth outcome. Specifically, undiversified mining companies whose operations exclude zinc production as the primary source of revenue would benefit most from adoption of this project.

Jan 1, 1993

By Paul Soros

The Conneaut, Ohio, terminal of the Bessemer & Lake Erie Railroad was the first rail-to-ground-to-water coal terminal on the Great Lakes. Compared to the traditional method of holding coal in railroad cars at the ports for dumping their contents into vessels, it provided for: a. Immediate train turn-around independently of vessel arrivals. b. Winter storage of coal at the port, permitting year round shipment by the mines and year round operation of the railroad.

Jan 1, 1969

By H. V. S. Tingley

My topic today is future trends in compensation for the mining industry. I seldom get the chance to speak about a subject of such immediate interest to an audience, so I would like to make the most of this opportunity by telling you that everybody in this room will become rich beyond his wildest dreams in the next few years. I would like to open my talk that way, but in compensation, like everything else, there is a great gap between dreams and reality. Back to reality. When we talk about compensation, we?d better define our terms because the compensation is really an umbrella for five basic types of payment made to management personnel. Slide 1 identifies these elements of compensation.

Jan 1, 1980

By R. Wisniewski, S. Schafrik

Every underground coal mine in the United States must deploy and operate a wireless communication and electronic tracking system. This paper addresses the reliability and availability of an installed tracking system and the communications infrastructure that supports it. This paper assumes that the tracking system uses the communication system to perform its operation. A particular interest is the requirements for the systems to operate continuously without failure after a mine disaster for 24 hours, and the requirements in the MINER Act for the tracking systems to be “functional, reliable and calculated to be serviceable” and the communications systems “redundancy.” These requirements imply a certain reliability and availability. This paper describes a quantitative way to assess these systems requirements, using tools that are available to and commonly used by the reliability, maintainability and availability community.

Jan 1, 2014

By RALPH BALTES, AMIR EHSAN KIANFAR, FABIAN UTH, ELISABETH CLAUSEN

  Underground positioning and communication are essential technologies for the future of underground mining operations. In contrast to other positioning and communication technologies such as wireless local area network (WLAN) or radio frequency identification (RFID), ultra-wideband (UWB) radio technology provides significant benefits like accurate and robust positioning of mobile machine equipment, which is indispensable for future autonomous systems in underground mining processes, such as production, transportation and auxiliary operations. Among these technologies, UWB offers many advantages, including higher accuracy, robustness, resistance against noise and multipath effects, and low power consumption [1,2]. Underground automation and localization systems benefit from these advantages and use the technology to improve efficiency and safety. There are many studies being carried out on this technology to increase the results’ accuracy, energy sufficiency and more. Two robust UWB modules that were developed for underground positioning and collision avoidance with regard to human safety in underground mining operations are introduced. The measurement results of tests carried out in an underground mine are discussed as well to confirm the functionality of the system.

By Thon T. Gin

The lithologic, mineralogic, and magnetic beneficiation characteristics of the iron formation at U. S. Steel's Atlantic City Ore Mine, Fremont County, Wyoming, have been determined. The iron formation averages about 30 percent Fe content, and varies from 125 feet to about 500 feet in thickness. It is composed of interbedded magnetite-rich quartzites, magnetite-quartz-amphibole schists, and amphibole-chlorite schists. Quartz, actinolite-tremolite, chlorite, and magnetite are the essential mineral constituents. These rocks are differentiated into four major ore types on the basis of their relative quartz and amphibole content. The iron content of the magnetic concentrate decreases and the silica content increases with decreasing grain size and increasing amphibole content in each ore type at the same fineness of grind. Criteria were developed to enable the mine operator to recognize the ore types and to blend them to produce a more uniform concentrator feed. This results in less variation in product quality and requires fewer changes in operating conditions-in the concentrator.

Jan 1, 1965

By Nathaniel Arbiter

The increasing size of flotation cells as the use of flotation has increased is traced from the first United States application of the process in Montana in 1911 through the following eight decades, using data from the Taggart handbooks (1927) and (1945), from the SME Handbook (1984), and from recent manufacturers' catalogues and other sources for the 1980s and 1990s. With the earliest mechanical cells less than 1 m3 (359) in volume and the largest now available at 200 m3 (7,000ft3), three requirements are necessary: 1) demonstration of advantages in replacing smaller volume by larger volume cells; 2) estimating power requirements, impeller dimensions, and operating rpm by correlation equations; 3) considering effects of using larger cells, in necessarily much shorter rows, on process kinetics. The resulting seven tables that address these problems are presented, and their implications discussed.

Jan 1, 1999

By Y. C. Kim

Although the first published optimum pit limit design algorithm by Lerchs-Grossmann dates back to 1965, the majority of the open-pit mines in the U.S. has not as yet adopted such a rigorous optimization algorithm. Instead, the floating cone approach initially developed by Kennecott Copper in 1961 is still used today for various reasons. However, shortcomings with the floating cone algorithm, particularly for precious metal deposits with erratic mineral distributions, have provided a renewed interest in optimizing algorithms.

Jan 1, 1988

By Gilles Recher, Jörg Riechers, Albert Lueghamer

"INTRODUCTIONIn view of a global trend towards urbanization, more and more trunk sewers and combined sewer overflow tunnels (CSO) with medium to large diameters and the corresponding link sewers are currently built and under design. Shielded tunnel boring machines using segmental lining as tunnel support represent an efficient solution for construction of new wastewater and supply tunnels. Especially in the field of sewers, the durability of concrete structures both exposed to any groundwater present on its exterior and to aggressive waste water as well as gases on its interior is a key requirement. Despite thorough research on segmental lining and mechanized tunneling machinery, conventional thermoplastic liners show comparatively minimal progress in terms of practical advancements. This is in contrast with the development of the latest segment embedded high density polyethylene (HDPE) system. Based on experiences achieved, this paper discusses the latest development of an integral protective lining system in respect of material characteristics and its adaptability to both project and customers’ demands. Reviewed performances, as the bondage behavior of the embedded HDPE system at axial stress loads due to acting thrust cylinders during ring build as well as the ability to drain pressurized water behind the embedded membrane, tested at full scale segments, are also presented. The paper is round off by presenting first details of sewer projects endeavoring to utilize this cutting-edge solution for an integral concrete protection, which will be commenced beginning of 2016.CASE HISTORIES ENCOURAGE ADVANCEMENTS Past experience has shown that unprotected concrete surfaces as well as chemical based linings such as coatings, sprayed linings and cured in-place-systems cannot reach the desired life times. Also the fact that in deep tunnel sewer system hardly maintenance is possible, a durable and maintenance free system is required which only can be reached by applying mechanical anchored HDPE (CPL)."

Jan 1, 2016

By J. Y. Hwang

Alunite has been utilized as raw materials for producing alumina and potassium sulfate fertilizer in Russia for many years. In the United States, this mineral has not been commercially processed though reserves of 5 to 10 billion tons of alunite ore have been estimated. Major constituents of these ores include quartz and alunite. The minerals are finely intergrown and liberation occurs below 10 microns. Adequate separation techniques for such fine particles have not been developed. A new method for the beneficiation of alunite ore is proposed in this study. 'Ibis method utilizes a small amount of fine magnetite upon which the liberated quartz is selectively flocculated. The co-flocculated magnetite and quartz are then separated from the alunite in a high gradient magnetic separator. Clean products, e.g. an alunite concentrate of 90% grade with 80% recovery, has been obtained from an Utah ore. Techniques for the selective co-flocculation of magnetite and quartz, the separation of the carried quartz, and the recovery of magnetite after separation are discussed.

Jan 1, 1985

By G. E. Sreedhar, R. Kumar

The pockets of high silica blue dust across the entire high grade hematite deposits in the Bailadila sector bothers the excavation activity due their iron content, which is higher than the threshold value specified by the Indian Bureau of Mines and the agony of stacking them separately due to their fragile & powdery nature. The physical nature of blue dust and its negligible alumina content makes these a potential source of hematite, which is a blessing in disguise. As most of the particles are in the form of an independent grain making it appropriately suitable feed for dry magnetic separation and thus the dry beneficiation has turned a bane into boon by enabling to produce concentrate either suitable for using as DSO or amenable for blending. The emphasis on carrying out dry beneficiation studies in the present context serves the purpose of mineral conservation, mitigates the issues of excavation and stacking as well as conservation of water resource. This paper describes the laboratory and pilot scale dry beneficiation studies carried out on blue dust of 48 – 60%Fe and Silica up to 30% at 25 Kg/hour to 400 Kg/hour, resulting in production of concentrate assaying 60 – 65%Fe. INTRODUCTION High silica blue dust (HSBD) is associated with Banded Hematite Quartzite (BHQ) and is available in abundance in various pockets across the Iron ore body in the Bailadila region of Chhattisgarh state. High Silica Blue dust occurs in the form of free granular particles and also as friable lumps. The chemical quality of this falls under sub-grade category (45 – 55%Fe) and as per the guidelines of Indian Bureau of Mines, these are to be stacked and conserved as future resources of Iron if it can’t be utilized in the present circumstances. Due to its friable nature, stacking of HSBD is a challenge and it is also compounding the problem by polluting the air under high velocity wind conditions. Because of its physical nature and occurrence in pockets pose challenge to systematic mining. The existing processing set up of the operating mines is designed to treat either Direct Shipping ore (DSO) or Run-of-Mine (ROM) have grade >60% Fe. The present practice of beneficiating iron ore fines (<1 mm) comprise combination of two or more processes such as desliming, hydraulic classification, magnetic separation and flotation apart from requirement of grinding depending on liberation characteristics. The HSBD which is predominantly occur as free granular particles, is significantly low in its alumina content. This gives us an opportunity to utilize them by exploring a suitable beneficiation process so that the concentrate produced can be used as a sweetener for alumina rich iron ore/concentrate. Thus, in the present study, an attempt has been made to adopt dry high intensity magnetic separation technique to explore the amenability of the high silica blue dust for beneficiation.

Jan 1, 2019

By Lok W. Home

HISTORICAL DEVELOPMENT At the beginning of the 1970 more than 90% of pro¬duction drilling in open-pit mining was obtained with the use of rotary drills. At the same time, the use of rotary drills underground was virtually nonexistent. Several progressive mines began questioning whether efficient rotary drilling could not be adapted to under¬ground applications. In the late 60s and early 70s at¬tempts to use rotary drilling were made by Inco, Ltd. and Meramac Mining, utilizing drill units designed as a combination of small diameter raise drills and rotary drills. These initial attempts were unsuccessful primarily due to the immobility of the equipment and low degree of dependability. At the same time, experiments con¬ducted by Inco and Meramac using large diameter in¬the-hole percussion drills produced immediate encourag¬ing results. The first serious attempt at utilizing rotary drilling underground was made by Texasgulf in 1971 at Kidd Creek mine in Canada. An experimental stope 15 m wide, 36 m long, and 30 m deep was drilled using 200-mm diam rotary drilled holes. The machine used was a Robbins&apos; Model 11 D. The Model 11D is a rotary drill designed to drill drain and utility holes under¬ground. The results of this test revealed that large diameter blasthole stoping was feasible. The indications were that the major areas of concern-fragmentation and pillar damage-could be controlled and a new low-cost stoping method resulted. At this point Texasgulf and Robbins entered into a cost-sharing agreement to develop a rotary drilling unit specifically for this stoping method. Drilling of the trial stope required pouring a concrete pad at each drill hole plus anchoring the derrick to the pad by means of rock¬bolts. Utilization expressed in terms of drilling time to available time was less than 20%. It was obvious that the required unit had to be mobile, setup time had to be minimized, and rod handling had to be improved. The first attempt at an underground production-type rotary drill consisted of mounting the basic 11D on an air-powered Eimco 600 Series crawler. The crawler was equipped with four screw-type leveling jacks operated by an impact wrench; rod rack facilities for 60 m of 1.2-m long, 170-mm diam rods; a rod handling facility consisting of an air-lift swing boom and a pipe loader which automatically positioned the rod under the float¬ing drive box; a turnbuckle anchor system requiring in¬stallation of four rockbolts in the drill drift floor and placing turnbuckles from the rockbolts to the corners of the drill; and trailing power units containing the electrics and hydraulics required to operate the drilling unit. Operation of this unit revealed a vast improvement in drilling time but some problem areas remained. The anchoring system required secondary drilling and proved difficult to adapt to the localized irregular floor surface and the trailing power unit was difficult to maneuver and was causing unnecessary maintenance costs. Addi¬tional improvements resulted in the standard 11MD rotary blasthole drill. DESCRIPTION OF UNIT This standard model consists of the drill and the power unit integrally mounted on an air-powered crawler chassis (Fig. 1). The rod-handling and leveling¬jack systems are similar to those used on the prototype Texasgulf unit and remained relatively the same. The anchoring system has been replaced by the roof jack, initially screw type but now hydraulically actuated. The anchoring system is necessary as the drill exerts more thrust than the weight of the unit. During operation it is found that the two front jacks adequately anchor the machine. The complete unit&apos;s operational dimensions are: height, 3.2 m; width, 2.1 m; and length, 4.2 m requiring a 3.5- x 3-m drill drift. The derrick is pivot mounted and raised and lowered by a hydraulic cylinder reducing the transport height to 2.5 m. The derrick is also turnbuckle mounted to allow dip angle drilling from vertical to 0.52 rad (30°) off vertical. The drill derrick can be mounted to allow dip axis to be parallel or perpendicu¬lar to the long axis of the unit. The standard rods are 1.2 m in length and are contained in racks of 10 which can be removed for transportation. Drilling torque is produced by a 56-kW (75-hp) electric motor driving a double vane pump which in turn drives a Robbins high torque gear-type hydraulic mo¬tor. In addition to the hydraulic motor, the machine drive system has a 3.9:1 planetary gear reducer. This results in six speeds with the following minimum and maximum range: Maximum rpm 112 Torque 3725.5 J (380 kg m) Minimum rpm 10 Torque 14 706.0 J (1500 kg m) Drilling thrust is provided by two bootstrap cylin¬ders pressurized by a variable volume pump. This sys¬tem can produce from 0 to 267 231.2 N thrust in either direction. Bailing air (approximately 17 m3/min at 382.2 to 490.3 kPa) is introduced through a rotary swivel pass¬ing directly through the center of the drive system to keep efficiency and losses to a minimum. Hole annulus is also kept to a minimum by using 170-mm rod when drilling a 200-mm hole. A small amount of water is added to the air for dust suppression. The machine has to be supplied with air, water, and electrical power. It does not appear feasible to provide an integral air power supply with the rotary drill such as is done with open-pit rotary drills. Air is required and installed during the primary development of the drill drift. The machine can be adapted to drill hole diameters from 170 to 228 mm for blasthole operations. The drill string consists of the rotary bit, crossover stabilizer, roller stabilizers, and standard rods. The operator controls speed and thrust pressure from an operating console which can be mounted in a conve¬nient position. Mount Isa has made an adaption to the operating console to permit remote collaring of drill holes in an uncleared floor.

Jan 1, 1982

By David M. Abbott

This paper is a companion to, and amplification of, the ?History? section of the 2014 version of the SME Guide for Reporting Exploration Results, Mineral Resources, and Mineral Reserves (SME Guide). The need for the careful examination and evaluation of mineral deposits has long been recognized. In the book De Re Metallica, Georgius Agricola noted, ?Moreover, a prudent owner, before he buys shares, ought to go to the mine and carefully examine the nature of the vein, for it is very important that he should be on his guard lest fraudulent sellers of shares should deceive him? (1556, p.29). Agricola further stated, ?Now a miner, before he begins to mine the veins, must consider seven things, namely: the situation, the conditions, the water, the roads, the climate, the right of ownership and the neighbors? (1556, p. 30). The elements of Agricola?s seven things, much expanded, are incorporated into the 2014 SME Guide. As reflected in this quotation, veins were the primary concern of mining until 20th century technology permitted bulk mining techniques. The need for standardization of reserve descriptions arose along with the development of western mining in the United States and the concurrent development of mining engineering and mining geology as professions. By the turn of the century, debate about terminology of various classes of reserves was in full swing. Herbert Hoover noted in 1909 (p. 16-17), ?The old terms ?ore in sight? and ?profit in sight? have been of late years subject to much malediction on the part of engineers because these expressions have been so badly abused by the charlatans of mining in attempts to cover the flights of their imaginations. A large part of Volume I of the Institution of Mining and Metallurgy has been devoted to heaping infamy on these terms, yet not only have they preserved their places in professional nomenclature, but nothing has been found to supersede them. ?Some general term is required in daily practice to cover the available field of visible ore, and if the phrase ?ore in sight? be defined, it will be easier to teach the layman its proper use than to abolish it. In fact, substitutes are becoming as badly abused as the originals ever were. All convincing expressions will be misused by somebody.? Hoover (1909) noted that the common terms at the time were: ? Positive ore or ore developed: Ore exposed on four sides in blocks of a prescribed size. ? Ore blocked out: Ore exposed on three sides within a reasonable distance of each other. ? Probable ore or ore developing: Ore exposed on two sides, ? Possible ore or ore expectant: Ore in whole or in part below or beyond the range of vision. Hoover stated that these, and similar terms, overlapped and had the difficulty of failing to account properly for geologic variation in metal distribution beyond the exposed face. Certainly assuming extension of values along a vein is reasonable, but how far? Also, these definitions are for vein deposits, not all types of deposits are in veins. Hoover (1909, p. 19), therefore, defined the following terms. ? Proved ore: Ore where there is practically no risk in failure of continuity. ? Probable ore: Ore where there is some risk, yet warrantable justification for assumption of continuity. ? Prospective ore: Ore that cannot be included in the above classes, nor definitely known or stated in any terms of tonnage.

Feb 1, 2014

By R. F. Davis

The evaluation and selection of coals for producing metallurgical coke is indeed a com- plex process simply because coal is a complex and variable substance which is sensitive to how it is treated from the time it is mined until it is transformed into coke. A review of the the more common evaluation tests made on coal and how the test results are applied in commercial practice. Parameters used to select coal blends for wet and preheated charges should also be of interest.

Jan 1, 1980

By M. C. Mound, L. Fradette, C. Colbert

Metallurgical Accounting in the mineral processing industry transforms accumulated process data, including flow rates and assays, into a coherent information format. This is used to rapidly provide production reporting and key performance indications. A fully comprehensive and coherency of available data must be a component of any system expected to accomplish reconciliation in the mass balancing process. Quality issues are thus improved with such desired methods via a mass-balancing engine utilizing the results of measurements acquired by various on-line sensors, analyzers, and sophisticated laboratory equipment. Metallurgical Accounting, when accomplished through such an engine, provides high value information in a simple, straightforward, and simplified manner. Exceptional utility is then transparently available to authorized personnel for access to metallurgical accounting reports, production reports, mass balance results, performance indicators, and so on. This paper discusses how such information can be used to "drilldown" into each result set by consulting the data hierarchy to evaluate and validate calculations and input data used to produce the specific results being queried. The power of such a system resides in the full and true integration of all production and laboratory data. What is integrated are the data thus acquired via a single user interface, a single database, a single configuration tool, etc. From this comes the derivation of contextual information and its maintenance. It is possible to reduce metallurgical accounting and production reporting from possibly hours or even days to a matter of minutes. The result is maximization of information reliability and availability from masses of otherwise discrete and difficult to access key data.

Jan 1, 2003