Search Documents

MINExpo International is billed as the largest exposition for the mining and mineral processing industry. And the 2012 edition, scheduled for Sept. 24-26 in Las Vegas, NV, is no exception. Put on by the National Mining Association (NMA), attendance at this year?s show is expected to be significantly more than the 38,500 who attended the last MINExpo in 2008. The exhibit will also be quite a bit larger in 2012 than it was at the previous MINExpo. More than 1,800 companies, representing more than 30 countries, will fill the Las Vegas Convention Center. The more than 850,000 sq ft of exhibit space will include the North and Central halls as well as South Halls Nos. 3 and 4. And the Silver Lot outside of the front door, under construction in 2008, will be filled with more exhibitors. The 2008 show attracted about 1,220 exhibitors occupying more than 600,000 sq ft of exhibit space.

Jan 1, 2012

By Y. P. Chugh, J. Ma

Higher production, better safety standard, and potential for automation are some of the benefits of longwall mining. Today, longwall face advances at a faster rate exposing many diversified rock layers in a short period of time. It is now a serious challenge to cope with ground control problems such as roof falls, face and floor failure, and excessive shield loading as fast as possible to minimize production and monetary losses. In Illinois coal mines, the existence of weak floor strata blow the coal seam may pose additional problems related to floor heaving, shield base punching, and associated roof and face falls. In this study, the effects of weak floor on longwall ground control are analyzed using two-dimensional finite element models. A two-leg 635.6-ton (700-short-ton) yielding capacity shield is included in the models to evaluate the effects of different thickness and material properties of the weak floor. The study indicates that the thickness and material properties of weak floor have significant effects on shield loading, the distribution and intensity of front abutment stress, failure zones in the surrounding strata, roof-to-floor convergence, and floor punching by the shield base.

Jan 1, 2000

By J. A. Lombardi

Acid-Minesite-Solutions (AMS) are defined as copper-containing pit lake, tailing pond, acid-mine-drainage, and heap and waste dump irrigation solutions. All of these solutions are characterized by copper, acid and water contents that have value as individual commodities. HW Process Technologies, Inc. (HWPT) has developed nano- and hyper-filtration membrane methods for the separation of copper and other base metals, acid and water from AMS. These treatments are collectively called HWPT?s Engineered Membrane Separation® (EMS®) systems. The EMS® method of copper recovery produces small volumes of higher-concentration copper solution from large-volume, copper-dilute AMS. A case study of the 4,000 gpm Cananea EMS®-AMS plant for the recovery of copper from an acid-pit-lake resource is described. The EMS® method of copper removal from AMD and tails pond waters has been bench-scale demonstrated and are described, complete with projected budgetary capital and operating costs. Additional treatments for the recovery of sulfuric acid and high-quality water from the permeate (membrane passing) waters for the above-described AMS treatments are presented, with budgetary capital and operating cost estimates. [ ]

Jan 1, 2009

The selection of the mining fleet can have as much of an effect on the efficiency and effectiveness of an operation as the mining method. This is not to say that inefficiencies are only attributable to inappropriate equipment selections, these aspects have many factors but are not the subject of this paper.This paper will give an overview of equipment selection processes that have been utilised to date. It will also look at the increase in application of study programs/simulations from an aspect of accuracy, as well as the importance of enabling the analysis of multiple sensitivity scenario planning. An aspect that is increasingly important in project planning with commodity market movements.Another aspect that is increasing in popularity is that of automation, what effect does this have on equipment selection? What additional aspects need to be taken into consideration when assessing Automation of equipment from the beginning of a project as well as introduction into an operating mine?Once the selection process has been finalised and equipment implemented, how do we, as an industry, 'close the loop' through analysis of estimated versus actual equipment application?

Dec 6, 2010

By R. G. Knickerbocker, T. E. Evans, D. R. Torgeson

"INTRODUCTION Sponge iron is a product resulting from the reduction of an iron oxide at such a low temperature that fusion does not occur, and the reduced particles retain substantially the same shape as the original ore. The removal of oxygen in the reduction process leaves the metal porous and reactive. Sponge iron may be compared in general to a chemically precipitated substance insofar as reactive properties are concerned. The high specific surface and the orientation of metallic structure are factors which probably contribute to the reactive properties of sponge iron.The term ""gaseous reduction,"" as applied to iron ores, required clarification. Strong evidence exists, for example, that ore is partly reduced to sponge iron by carbon monoxide in the blast furnace at temperatures around 800° C. at a point that may be as high as 30 feet above the tuyores. In 1923 and 1924, Sims and Wood attempted to reduce iron oxide with carbon in an Arsem vacuum furnace at 980° C. These investigators found that only 6 percent of the iron was reduced to metal when the iron oxide-carbon mixture was heated for 1 hour under evacuated conditions, whereas at atmospheric pressure 70 percent of the iron was metallized. Their results indicate that the process of iron-ore reduction at temperatures below the melting point of the ore may proceed largely, if not entirely, by the action of reducing gases even when the reducing agent is solid carbon. Therefore, the term ""gaseous reduction,"" as used heroin, is defined as a process in which iron ore is brought into intimate contact with a reducing gas produced in separate-equipment from the reduction chamber itself.A large amount of pilot-plant development on gaseous reduction of iron ores has been carried out by the Bureau of Mines at the Boulder Experiment Station and had as its objective the reduction of fine iron ore by means of producer gas. The use of use gas was prompted by two considerations: First, the possible utilization of large reserves of Western noncoking bituminous coals and lignites contiguous to iron-ore drewwing; and second, an investigation of the results that might be achieved in the pilot-plant gaseous reduction of fine iron ores by means of a relatively reducing gas. The results obtained, it was felt, would be of considerable value in indicating the direction which gaseous reduction experimentation must take for the development of a commercially practicable and economic process for the production of sponge iron."

Dec 1, 1946

By L. A. Conley

This report, covering the period January through December 1976, contains abstracts of articles related to cost engineering and economics for chemical and petroleum plants, mining, and other mineral industries from the following periodicals: 1. Air Pollution Control Association Journal 2. Chemical Engineering 3. Chemical Engineering Journal 4. Chemtech 5. Coal Age 6. Coal Mining and Processing 7. Combustion 8. Drilling-DCW 9. Electrical World 10. Engineering and Mining Journal

Jan 1, 1977

By Edgar S. Rush

This study was conducted to make a limited evaluation of experimental and standard tractor dozer blades. A field test program was conducted in the southeastern part of Kansas on strip-mined areas where the spoil banks are parallel with rest-to-crest distances between 90 and 120 ft and maximum dozing distances usually less than 50 ft. This evaluation was a part of an overall joint Pittsburg and Midway Mining Company--U. S. Bureau of Mines (USBM) Specialized Reclamation Field Test Program primarily centered on the field t sting of experimental high-volume lateral relocation blades. The three blades evaluated were the 60-ft-wide angle (A) blade mounted on two 41B tractors. a 48-ft-wide A blade mounted on two D9H tractors, and a 13-ft-wide reclamation universal (Rec U) blade mounted on a D9H tractor. In addition to the experimental blades, three commercially available blades were tested: A 20-ft universal (U) blade mounted on two side-by-side (SxS) D9H tractors; a 20-ft U blade mounted on a 418 tractor; and a l2-ft straight (S) blade mounted on a D8H tractor. The dozer blade evaluations compared measured blade performance with soil and other site characteristics and with estimated earth-moving performance rates based on earthmoving methodology that accounts for the traction and speed of the tractor. The earthmoving methodology was also validated with data collected during this program.

Jan 1, 1978

By R. W. Stahl

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to mineral industries' mines, quarries, and plants that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove that efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1963

By M. S. M. Aljuhani

In this paper, one of the human factors that affect productivity in an underground gold mine in Saudi Arabia was investigated and analysed for the purpose of improving productivity. The human factor that was investigated is labour utilization and labour productivity. In the selected mine, labourer?s performances were measured carefully. It was found that in this mine, workers spend only 65% of the shift time in a productive work, and they spend 35% of the shift time in non-productive activities. As a result, recommendations were presented to enhance productivity in the selected underground gold mine by enhancing labour utilization.

Jan 1, 2002

By FREDERICK MCAKCCOY

THE production of tin from Mexico has never reached the point of being considered a national industry, but the distribution of tin ores is so widespread that there are possibilities that one day it may become of importance. Of the twenty-seven states of the Republic, tin claims have been taken up in sixteen. In all there had been taken up to the end of 1926, two hundred and twenty-five claims, of a total area of about 7400 acres. The first historical mention of tin in the Americas is found in a letter of Cortez to the Emperor, Charles the Fifth, of Spain, which is as follows: Speaking of his manufacture of some small cannon, he says: "For these reasons I took considerable pains to get copper from some provinces of this country, and bought it at a high price in order to get it quicker.

Jan 1, 1929

By S. H. Brown

In our work as health physicists*, we do a lot of public speaking and interaction with the public on issues related to development of uranium mining and milling (?uranium recovery?) in the US. Understandingly, the public has important concerns about this. Accordingly, this paper is presented in a ?question and answer? format in which we have tried to capture what are some of the most common concerns we hear from citizens and address them. We have attempted to do so based on the best scientific information we have, representing information well documented in peer-reviewed scientific literature and consensus positions from both national and international scientific standard setting bodies and related committees. We have included some of the more important of these scientifically-based references to support the information provided. Practical space limitations prevent completeness in this regard in some cases. Visit the Health Physics Society?s web site or feel free to contact me directly for additional references, information or detail ? Steve Brown. The health physicist?s primary objective is to manage the beneficial uses of ionizing radiation while protecting workers and the public from potential hazards. For more information on what a health physicist is and on the Health Physics Society, visit the Society?s web site at www.hps.org.

Feb 23, 2014

By Roberto Rosario

El presente trabajo la factibilidad de la evaluación realizada en la capacitación del personal minero. Esta evaluación comprende el control de calidad del producto formativo y para ello, es necesario que se definan los objetivos deseados con dicho trabajo y que los efectos se mantengan a lo largo del tiempo. En esta perspectiva, la capacitación fue aplicada en Pan American Silver de la mina Quiruvilca en el mes de octubre y la evaluación se desarrolló dos meses después. Las etapas de la evaluación fueron: entrada, salida y desempeño (autoevaluación). Esta última permitió conocer el conocimiento obtenido en los participantes, concluyendo en un resultado positivo en tanto mejora el autoestima, actitudes, comportamiento laboral y desempeño.

Sep 13, 2001

By T. R. Ellis

Australia’s mineral valuation code continues to evolve, while mineral valuation standards are also being written for Canada and Southern Africa. The author is leading a task force for writing the extractive industries addition to the International Valuation Standards. Meanwhile, the International Accounting Standards Board is continuing the development of an extractive industries addition to its International Financial Reporting Standards, with an emphasis on valuation reporting. This paper analyzes the need, content and ownership for a U.S. minerals appraisal standard in the context of both these developing international standards and also existing U.S. regulations and appraisal standards. The author provides many questions for research and debate.

Jan 1, 2003

By J R. Leeming

Mines require ventilation to ensure an adequate atmosphere for the sustenance of life, and to dilute, render harmless and remove contaminants.This paper describes the developments in the United Kingdom (UK) from natural ventilation, through the introduction of fire and simple fans, to modern fully independent and remotely monitored and controlled installations.CITATION:Leeming, J R, 2017. The history of mine ventilation in the United Kingdom, in Proceedings Australian Mine Vent Conference 2017, pp 271–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Kenneth Eltschlager

Business says that location is a primary component of being successful. So too is the importance of location in blasting. For blast seismograph data to be useful, the location of the blast and seismograph must be clearly documented. Another location of importance is that of a nearby structure. Establishing the spatial relationships between the blast, seismograph and nearby structures, allows the blaster to correctly interpret the data, evaluate the performance of the blast and gauge the validity of any complaints.

Jan 1, 2004

By R. Todd Swinderman

"Higher production demands across all bulk handling segments require increased efficiency at the lowest cost of operation, in the safest and most effective manner possible. As conveyor systems become wider, faster and longer, more energy output and more controlled throughput will be needed. Add an increasingly stringent regulatory environment and cost-conscious plant managers must closely review which new equipment and design options align with their long-term goals for the best return on investment (ROI).There are primarily two separate market segments using conveyor belts. One is in process industries such as food, chemicals, paper and powders. Handled in relatively low volumes, the bulk materials that enter these processes are generally of a consistent size and quality. The other market includes mining, coal handling and cement, where the bulk material’s quality and size vary, and the volumes are typically much greater. While both segments face similar issues with safety and environmental control, the properties of the materials handled and the volumes transferred suggest different approaches, with one thing in common: increased belt speeds requiring modern equipment upgrades.Safety at higher belt speedsWith companies recognizing that safety does indeed pay, safety is likely to become a new source of cost reduction. The percentage of mines and processing facilities with a robust safety culture are likely to increase over the next 30 years to the point where it is the norm, not the exception. In most cases, with only a marginal adjustment to the belt speed, operators quickly discover unanticipated problems in existing equipment and workplace safety. These problems are commonly indicated by the larger volume of spillage, increased dust emissions, belt misalignment and more frequent equipment wear or failures."

Jan 11, 2018

This article presents a proposal for the rehabilitation of the mined area of the Mogiana quarry. The Mogiana quarry produces material used in civil construction and is situated in the Brazilian State of Spo Paulo in the kilometre six of the Mogf Mirim - Itapira highway. The mineral exploitation in the Mogiana quarry provokes modifications in the environment such as alterations in the relief, vegetation, quality of the air, water and landscape. Through previous study of the area it was verified that after the closure of the exploitation the mine should be occupied mainly by pasturage. At the closing of the mine the exploitation benches, berms and slopes in general as well as the surrounding areas should be covered with a layer of soil and vegetated with native species in order to mitigate the negative impacts caused by the mine. The rehabilitation project of the area is based on the probable future use of the area, located between agricultural cultivations and cattle creation. The great alteration of the relief and soil would make future use of the area for agriculture difficult. It is more suitable t0 animal creation, mainly cattle. The high and thick rock slopes originated by the mining should be covered by vegetation, where possible, to reduce the negative visual impact. Obviously several measures will be necessary to reduce the impacts on the environment during mining. The final and definitive reclamation will only be possible after abandonment of the area. The main aspects of this reclamation process will be discussed in this paper.

Dec 6, 2010

By J. L. van Niekerk, J. Gunaselvam

This study investigates the use of appropriate seating systems for the control of whole-body vibration exposure in vehicles used in the SA mining industry. Six suspension seats were tested with six test subjects to determine the most suitable seat for an articulated dump truck based on the EM1 requirement in ISO 7096 (2000) standards. Transmissibility functions were measured in the laboratory using the newly commissioned Dynamic Seat Testing Facility with two excitation levels of 1m/s2 and 2 m/s2 r.m.s. in the 0.5 - 30 Hz frequency range. SEAT values were calculated for two input spectrums, the EM1 input spectrum specified as in ISO 7096:2000 and measured road vibration data measured on a typical articulated dump truck. The averaged SEAT value calculations indicated that not one of the seats will qualify as an ISO 7096 (2000) suspension seat but that it is possible to select a seat that will significantly reduce the vibration the driver will be exposed to.

Jan 1, 2003

By Lars Skogsberg

Work with hand-held power tools can be found in most industries all over the world. This type of work exposes the operators to different kind of loads like gripping-forces, feed-forces, exposure to vibration and noise, holding hot or cold surfaces and the exposure to dust. Designing a power tool with good ergonomics is a matter of finding the best compromise. As a simple example, increasing the mass is not acceptable because it will increase the forces needed to handle the tool. At the same time increased mass will in most cases reduce the vibrations. Vibration disorders related to the use of hand-held power tools has been known and reported since long. It is therefore essential that low vibrating tools are developed and used. The new vibration regulations in Europe, based on the Physical Agents (Vibration) Directive, have put increased focus on the vibration control in industry. Forces acting on the tool cause vibration Tools for industrial use must be of very robust design to withstand the very hard use they are exposed to. Industrial tools are therefore normally designed with the main parts made of metal. From a vibration point of view this means that most tools can be regarded as rigid bodies, especially because the dominating frequency normally is equal to the rotational frequency of the tool spindle or the blow frequency for a percussive tool. These frequencies are with few exceptions below 200 Hz. Handles however can not always be regarded as rigidly connected to the tool. There are several examples of weak suspensions designed to reduce vibration transmitted to the hands of the operator. There are also examples of designs where the handles just happened to be non-rigidly connected and in some cases even in resonance within the frequency region of interest. Oscillating forces act on the tool and the result is vibration. Design principals In all cases forces are the source of vibration. This leads to the three basic principles to control vibration: • Control the magnitude of the vibrating forces. Examples are the balancing unit on a grinder or the differential piston in a chipping hammer. • Make the tool less sensitive to the vibrating forces. Examples can be when the mass of the guard on a grinder is rigidly connected to the tool to increase the inertia of the tool. • Isolate the vibrations in the tool from the grip surfaces. Examples are vibration-dampening handles on grinders or pavement breakers, the air-spring behind the blow-mechanism in a riveting hammer or the mass spring system in a chipping hammer.

Jan 6, 2006

By Michael J. Sapko, Gregory M. Green, Kenneth L. Cashdollar

The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted a joint survey to determine the range of coal particle sizes found in dust samples collected from intake airways of US coal mines. The last comprehensive survey of this type was performed in the 1920s. The size of the coal dust is relevant to the amount of rock dust required to inert the coal dust, with more rock dust needed to inert finer sizes of coal dust. Dust samples were collected by MSHA inspectors from several mines in each of MSHA's 10 bituminous Coal Mine Safety and Health Districts. Samples were normally collected in several intakes at each mine. The laboratory analysis procedures included acid leaching of the sample to remove the limestone rock dust, sonic sieving to determine the dust size, and low-temperature ashing of the sieved fractions to correct for any remaining incombustible matter. The results indicate that particle sizes of mine coal dust in intake airways are finer than those measured in the 1920s. This finer size coal dust in intake airways would require more incombustible matter to be effectively inerted than the 65% incombustible specified in current regulations.