Search Documents

By Jr. Wilkinson

In today's work environment a tremendous amount of data is required to provide the regulatory agencies justification to issue a mining permit. The demands for data, specifically environmental characterization data, grow and the mine plans must address the issues raised by the interpretation of that data. Computers and computer software can provide operators and consultants with the tools necessary to assimilate, digest and interpret these seemingly unmanageable data sets. This paper presents some examples of how Mincom's MineScape software can be applied to the task of developing coal mine permits in an electronic format.

Jan 1, 1996

By Peter Werner

Technological advances in mine equipment and milling processes have enabled mining companies to exploit ever lower grades of ore. The result has been larger disturbances, greater volumes of waste, a complex web of infrastructure, and an overall trend towards mega-projects that can extend over several square kilometers. This explosive growth in a mining operation’s disturbance footprint provokes an obvious question: What’s it going to cost to reclaim all of this? At face value, this can be an enormous financial liability for a company, but since the timing of reclamation may be years in the future for many operations, these costs can be heavily discounted thereby limiting the burden on the corporate balance sheet. Nonetheless, mining companies are eager to remove these liabilities as quickly as possible, conversely, regulators want assurance reclamation will, in fact, occur. How might one bridge these competing interests? Navigating the practical and financial requirements of a post-closure landscape requires foresight, judgement and assumptions, however, companies who do not adequately plan for these future expenditures when there is no off-setting income stream will likely face some difficult decisions. Simple risk analysis tools and utilizing the time value of money can help bring some clarity to this end-of-mine life phase.

Feb 1, 2025

By G. L. Dollinger, W. H. Hamilton

INTRODUCTION Design and development of new products generally proceeds through a phase of initial development and discovery based on the evolution of existing arts, followed by technical innovation and development based on both pure and applied research. The development of the mechanical tunnel boring machine (TBM) has followed a similar pattern, with the first machines closely resembling continuous coal miners. In general, however, the design of TBM's to date has been more a result of evolution and discovery than of new technical innovation, even though large sums of money have been spent on research and development. In particular, the results of experimental laboratory and field investigations have had little effect on tunnel boring machine design, and the better performance of TBM's today over those of 10 or 15 years ago, is due more to increased mechanical reliability and greater operating experience, than to improvements in penetration rates and rock fracture capability. The improvements made, have been mainly by the machine and cutter manufacturers who recognize the greater efficiency and economic advantage of utilizing large single row cutters with high load capacity along with large edge spacing. Are there any improvements to be made, therefore, in TBM performance without new and dramatic technological breakthroughs? Can TBM manufacturers design greater performance into their machines by a logical extension of the present art, and by applying what has been learned in the laboratory and field? Some, for example, believe that the kerf cutting system of boring rock is at, or close to, its opti¬mum and little improvement can be made in the present TBM concept.

Jan 1, 1979

By Abhilash, S. Sarkar, T. Venugopalan, P. Meshram

"To explore blast furnace slag as a secondary resource for rare earth elements (REEs), blast furnace slag containing lanthanum (La), cerium (Ce), erbium (Er) and neodymium (Nd) in concentrations of 17, 16, 4 and 44 ppm, respectively, was processed with sulfuric acid while optimizing the parameters of acid concentration, temperature and pulp density. The experiments showed that recovery rates of 92, 36, 35 and 52 percent for La, Ce, Nd and Er, respectively, were achieved at 1 to 5 weight/volume (w/v) percent pulp density using particles smaller than 250 µm and treating with 1 M sulfuric acid for one hour at room temperature. Raising the temperature to 95 °C promoted the dissolutions of Ce and Nd to 89 and 84 percent, respectively, for the same 1 M acid concentration and one-hour duration at 5 w/v percent pulp density. Cyanex 923 was preferred over Cyanex 301 for the purification of REEs from leach liquor. In another route, the leach liquor was subjected to precipitation with 0.5 to 1 M oxalic acid, resulting in a product with 4 to 5 percent concentration of REEs.IntroductionRare earth elements (REEs) are important materials in numerous high-technology applications, but they have high supply risk, giving rise to the study of new sources. The recycling of REEs has been well researched, especially on a small scale, but has not been widely implemented. Less than 1 percent of REEs were recycled in 2011 (Binnemans et al., 2013). REEs occur in a large number of minerals in oxidic compounds, such as oxides, carbonates, phosphates and silicates, and are present as mixtures at 10 to 300 mg/kg concentrations in many rock formations, such as basalts, granites, gneisses, shales and silicate rocks. The most abundant REE in the Earth’s crust is cerium (Ce), at a concentration of 20 to 70 mg/kg, followed by neodymium (Nd) and lanthanum (La), with heavier REEs being less abundant (Binnemans et al., 2013). REEs occur in nature in their oxidized forms in salts and minerals due to their electropositive nature and high affinity for oxygen. The possibility of recovering REEs"

Jan 1, 2017

By Erle I. Shobert

In the comparison and consideration of synthetic and natural materials, graphites represent a situation in which natural graphites amount to less than 10% of the total carbon and graphite production by weight, and less than 5% in dollar volume, There are few applications where it could not be re- placed by synthetic graphite. On the contrary, synthetic graphite materials can be engineered to cover an extremely wide range of applications. These include electrographite brushes for rotating machinery, pyrolytic graphite, graphite-impervious pipe, nuclear moderators, high purity spectrographic graphite, power tube anodes, graphite rotary shaft seals, and rocket nozzles. The special qualities of natural graphite and its limitations are delineated and the almost unlimited possibilities in artificial graphite materials are discussed.

Jan 1, 1964

By Edward J. Budill

One of the most dramatic innovations in the materials handling industry has been the development of stacker cranes and automated material handling systems. The stacker crane with its many capabilities and the development of reliable industrial automation controls have combined to produce dramatic achievements in an area once characterized by inefficiency lack of management attention, and capital investment. In many areas of application however, stacker cranes and high rise storage systems have been designed and installed with insufficient thought given to their integration into the overall operations of the plant or distribution facility. This paper will look at some new and interesting breakthroughs in the integration of stacker cranes and high rise storage systems into the total manufacturing plant system. In this paper we will refer to both bridge type stacker cranes and aisle stackers. The bridge type stacker crane was developed first and was initially developed with forks or other handling devices hoisted up and down a rigid or telescopic mast. This mast system was suspended from a trolley mounted on an overhead crane bridge. Today, the primary application of the bridge type stacker is in warehousing systems for handling basic metal products such as coils, bars, sheets and plates. There is no question that the bridge type stacker has achieved notable results in storage and handling of these commodities. However, a new area for stacker crane application has been developing which in many cases over-shadows the accomplishments in the storage area. This is the application of the bridge stacker as an integral part of the manufacturing processes, or in other terms the production applications of stacker cranes. The stacker crane has a number of attributes which makes these applications very important. First, the crane bridge provides the stable platform for the mounting of machinery which can accommodate the hoisting and lateral movement of large capacity loads. Today stacker cranes are being built with capacities of up to 30 - 40 tons. The bridge cranes can easily accomplish accommodation Of these large tonnages. Secondly, the mast system provides a stable platform for the mounting of a wide variety of manipulating devices which can be used for the placement of material into manufacturing processes, the extraction of this material from these processes, and movement to other points in the process area. These attributes combined with excellent operator control and safety have led to development of the stacker crane as a production tool.

Jan 1, 1973

By James R. Jones

The Surface Mining Control & Reclamation Act is a complex piece of legislation signed into law on August 3, 1977. It is the culmination of more than six years of debate by the Congress over the need for a national regulation of surface mining as opposed to the prior concept of regulation by each concerned state. It departs from the more normal type of law in that it includes very specific requirements, limitations and performance standards. In its procedural aspects, it is somewhat similar to the Clean Air Act and the Water Pollution Control Act in that it places primary responsibility at the state level, provided the state meets minimum national requirements. At the time of writing this paper, in late December 1978, the Interim Regulatory Program has been in effect for seven months. The proposed regulations for the Permanent Program, the draft Environmental Impact Statement, and the draft Regulatory (Economic) Analysis ware available for eight weeks before the close of the comment period on November 27. We are now awaiting issuance of the final versions of these documents. The states in which coal is mined, for the most part, have made sere revision to their state laws and are in the process of revising their regulations, or have just completed the revision, to comply with the Initial Regulatory Procedures. They are now faced with another new major effort to analyze and plan for compliance with the Permanent Regulatory Program, which is expected to be promulgated by the Office of Surface Mining of the Department of Interior by the time this paper is presented.

Jan 1, 1979

By Richard Gallagher, Russell K. McFarland

INTRODUCTION The Southern California Rapid Transit District has commenced Preliminary Engineering for an 18 mile Metro Rail Project. This initial line will consist of approximate 36 miles of single track tunnel and 16 subsurface stations. The estimated cost of $1.2 Billion in 1978 dollars, places it in the category of a major public works project. During the planning phase of this project, particular attention was paid to the National Academy of Science Reports, "Better Contracting for Underground Construction" (1974), "Better Management of Major Underground Construction Projects" (1978), and "Management of Urban Construction Programs" (1980). The improved transportation service that this project will furnish the Los Angeles Metropolitan Area will result in significant benefits that will add immensely to the economic well being of the community-which is one of Webster's definitions of improved productivity. RAPID TRANSIT PROJECT BACKGROUND Rapid Transit studies have been going c in the. Las Angeles area since 1925. In 1969 and 1974, sales tax ballot issues were not adopted by the electorate of the county mainly because the pre-ponderous of County voters are outside the City of Los Angeles.

Jan 1, 1981

By Jenna Wundrack, Evan Thibaud

The advanced cryogenic treatment is a post-manufacturing metallurgical process that involves subjecting off-theshelf materials to extremely low temperatures, significantly improving wear resistance and reliability. These case studies explore whether the claims of Enrich Bits & Tools benefit metals and their specific in-field application to drill bits in the blasting industry. This paper reviews the application of the treatment to button drill bits for enhanced wear resistance in two operations. The first is a civil construction project with highly abrasive rock. To confirm the remarkable benefits of the treatment, a second case study was performed. This case study utilized measure-while-drilling technology in consistent rock characteristics to reduce variables in the field study.

Feb 1, 2024

By Rainer Alles, Markus Keller

INTRODUCTION For overland conveyors of several kilometres length and as well as wide for conveyors designed for high mass flows, the cost for the conveyor belting share is 40% to 50% of the invested cost 173. The German Standard DIN 22101 is used for calculation and dimensioning of - conveyor belts and belt conveyor components. Developments in rubber technology and conveyor belt design required a revision of the standard released in 1982 121, which was published in August 2001 131. New research results and publications 16-9, 13-15] led to a better understanding of the material behaviour and their influences on conveyor belts. Test and calculation methods have been established to determine the most important parameters which are related to the performance of a conveyor belt line. These parameters are • The running resistance of the idlers • The indentation resistance of the belt • The dynamic splice efficiency • The distribution of belt load in the splices, transition zones and on pulleys. As a result, new rubber compounds with low indentation losses allow the use of reduced friction coefficients and thus lead to reduced power consumption, smaller drives and lower belt tensions. The deeper understanding of the flux of forces within belt splices led to both optimised splice design and optimised rubber compounds which significantly improve the dynamic splice efficiency. Therefore, in accordance with the standard, the benefits of these technologies and the better understanding of material behaviour allow a reduction of belt strength still maintaining sufficient safety factors. Thus engineers are enabled to calculate belt tensions more exactly and users are encouraged to pay more attention to starting and braking techniques. DETERMINATION OF DRIVE FORCE According to the DIN standards the resistance to motion generally has to be determined for each different section of the belt conveyor including upper and lower run separately. The necessary drive power P is calculated as [ ] with v as the conveying speed. The total of all resistances to motion of carry and return run can be determined as [ ] FHo and FHu are the primary resistances consisting of the running resistances of the idlers, the indentation resistance of the belt, the fulling of the conveyed material and the flexure of the belt. While indentation resistance and idler resistance are measurable, they have been deter- mined to be responsible for up to 70% of the primary resistances covered by FH. Further FN is the secondary resistance that covers, for example, the resistance of feeding points and scrapers. Fa are the total slope resistances and Fs is the total of all special resistances, resulting, for example, from belt steering devices. These three resistances should be neglected in the following discussion. For conveyors where a determination of the substantial parts of the resistances to motion is not possible, according to the new DIN standard [31 a determination of the drive power is acceptable by using the fictitious friction factor) [ ] In this formula the index i identifies the individual section of the conveyor, 1 is the length of the section and MR, MG and ML are the related masses of the idlers, the belt and the load in kg/m. The fictitious friction factor f determines the ratio between the overall resistance to motion and the total of moved masses within the

Jan 1, 2004

By Harold L. Lovell

The extensive heterogeneity of coal is a fact long recognized by scientists and engineers. However, until recent years the practical implications of such heterogeneity have more often been realized from an undesirable experience than from knowledge or forethought. Variations in the properties of coal, even within the same seam, eventually lead to procedural modifications in mining, handling, preparation and utilization. The concepts considered here propose an enhanced application of information, detailing these properties, realizing the uniqueness of any given coal seam but the practicality of a common approach. Coal preparation practice has been designed primarily for the control of ash and sulfur content to meet market specifications which are similarly specified, Other physical characteristics of size and friability are also commonly employed and, to a lesser extent, properties which are implications of rank. The consideration of petrographic data as indicators of origin, thus total physical and chemical properties, has generally been overlooked as a realistic tool in-the exploitation of coal as a resource. The evolution of descriptive techniques, whether petrographic, physical, or chemical, capable of universal application with any rank of coal, is still beset with problems.

Jan 1, 1968

By J. Van Kleunen

In the Spring of 1959 the Riverside Cement Company, a Division of American Cement Corporation, placed into operation at their Oro Grande California plant a new crushing-blending-reclaiming facility. This new facility, in conjunction with other modernization in the plant, has established a degree of automation and reliability on a-plant-wide basis which heretofore had not been attained in the industry. The blending and reclaiming facilities for raw stone and cement clinker at this plant represent not only the first computer programmed materials handling system of its type in the industry, but also the first installation of specialized equipment which was designed for high capacity, fully automated operations.

Jan 1, 1963

By Kyle A. Perry, Ethan A. Steward

The mining of underground coal presents several hazards for miners, including the risk of an explosion fueled by methane gas and coal dust. Methane gas, produced during coal formation, can continuously leak into old workings and build up through its lower explosive limit. Underground coal mines are required to maintain safe conditions, either by ventilating old workings or sealing them off using approved methods. Seals must be designed to withstand instantaneous pressures for a minimum of four seconds. A design strength of at least 50 pounds per square inch (psi) is required for atmospheres monitored and maintained inert, 120 psi for non-inert or not monitored, and greater than 120 psi for special cases. Due to the high cost and testing environment availability, most mine seals are designed through calculations and computer modeling and not subjected to full-scale testing in a representative environment. High pressure is not the only threat that mine seals may be exposed to. During an underground explosion, pressure waves and gas expansion may propel common mine items and objects to a high velocity, generating enough energy to damage mine seals and reduce their strength. Damaged mine seals may fail to contain their rated pressure, allow high pressure gas and fumes to vent through the seal during an explosion, or allow gasses to leak through the seal later after an explosion has occurred. This paper examines the effects of high velocity impacts of common mine materials and items on a reinforced mine seal rated to 120 psi.

Jun 2, 2023

By M. P. Adamson, Bryson D. Trexler, R. V. Ramani, Mark L. Koenig, V. Rajaram, Alan Burton, C. S. Crocker, Kim. Y. C., A. G. Law, William C. Larson

Another record year vas experienced by the mining industry as the value of nonfuel minerals production soared to $23.5 billion-up 15% from the previous year. Based on preliminary estimates by the Bureau of Mines, US mine output was the basis for about $225 billion worth of minerals-derived materials. Metal mining accounted for $8.5 billion, or 36%, of the total. Of the 22 metals produced in the US, 11 showed quantity increases, while 16 had value increases. Business Week's survey of 1200 companies (Mar. 17, 1980, pg. 81) revealed that 21 metals and mining companies had sales increases of 30% with earnings up 104%. Higher prices and increased demand for metals were primary factors behind the improved performance. The steel sector reported a 30% decrease in earnings for the year, but the slump was primarily the result of a $383-million loss for US Steel coupled with a 17% decrease in earnings at Inland Steel. Other firms did well in 1979, with earnings up 279% at Interlake and 269% at Kaiser Steel. Major obstacles facing the steel industry included substantial tonnages of dumped and subsidized imports, environmental expenditures, runaway inflation, and price controls. Turning to nonmetallic production, of the 49 commodities reported by the US Bureau of Mines, 29 had higher outputs and 39 had increased values. While production statistics may seem encouraging, government regulations continued to stifle industry efforts to develop needed new capacity. A case in point may be publication of the Environmental Protection Agency's simplified procedure to streamline five permit programs by consolidating them into one. The five included: hazardous waste management, national pollution discharge elimination, dredge and fill, underground injection control, and prevention of significant deterioration. The new procedure, published by EPA in the Federal Register, took 149 pages. AMC's J.A. Overton, Jr., noted that (MCJ, Nov. 1979, p. 39) to visually depict the complexity of the proposed regulations, Sell Oil Co. developed a flow chart mapping a path through one section. The chart required 10 days to map and two weeks for two draftsmen, using computerized drafting techniques, to plot the results. Overton said, "Perhaps the greatest service EPA has performed in preparing its proposal is to demonstrate again that federal regulations have become a complexity compounded by confu¬sion that culminates in a conundrum." While regulatory agencies promulgate new regulations, the lack of a cohesive government minerals policy remained a matter of significant importance to mine management. A non-fuel minerals study to provide input to the Administration for a national minerals policy program was a dismal shock, according to Rep. Jim D. Santini (D-NV). He said the first phase of the program, which was to identify industry problems, failed to come to grips with the hard decisions necessary regarding these problems, their impact, and their interrelationship. Santini said the report failed to acknowledge government's role in the process and absolved the government of any adverse influence on the domestic minerals industry. In response to the phase one report, eight senior mining executives testified before Santini's House Subcommittee on Mines and Mining concerning mineral supply, access to foreign sources, environmental protection, conservation and recycling, national security, and capital formation. By year's end, Rep. Santini promised to prepare a hard-hitting committee report on problems affecting the non-fuel minerals industry to provide a better base for subsequent policy recommendations (MCJ, Jan. 1980, p. 34). On the technological front, interest again centered on mechanization, automation, and scaleup to improve and expand production. Computer use increased for calculation of ore reserves, mine planning, operations research, and mineral processing.

Jan 5, 1980

The only good news in the exploration sector in 1982-a year plagued by low metal prices and weak demand-was precious metals. Gold in particular remained in the forefront, as it has for at least the past three years. The reason for this is partially due to gold's seeming resilience to conventional supply side factors-such as new production-that normally influence many other metals. Also, with projected production costs of about $6.40-$9.65/g ($200¬$300/oz), modest deposits with average grades can offer an early return on capital investment and good profit potential. Keeping escalating capital costs for new mining ventures within reason has shifted gold exploration efforts in recent years. Many mining companies are seeking relatively low grade, modest tonnage, near-surface gold mineralization. This, of course, leads to lower development costs using open-pit mining methods. Recent refinements in the carbon-in-pulp recovery process also has enhanced the economics of such deposits. Slumping economic conditions certainly played a key role in shaping exploration activity last year. Nearly every major mineral-producing state recorded exploration slowdowns. In Alaska, for example, development expenditures approached the level of exploration spending for the first time in the state's history. This not only reflects major companies' decisions to move toward production but also the economic slowdown. The worldwide recession stopped Nevada's exploration and mining boom "dead in its tracks," said John Schilling, state geologist. The year was one of layoffs and closings for the state's mines and exploration offices, he reported. Similar trends were noted in most other states, especially in the West and Southwest. In the Pacific Northwest, however, exploration appeared to continue at a relatively good pace considering the metals market. In the mining geophysical community, recent advances in telecommunications and microprocessor technology are continuing to provide a positive impact. Many geophysicists have begun using satellite digital communication links to access computer systems from remote sites where using a microcomputer would be difficult. There were also major contributions made in exploration geochemistry last year. Highlights include progress in formulating mineral deposit models, geochemical exploration in glaciated and arid environments, and publication of many informative books. The following state-by-state summary and articles on geophysics and geochemistry provides a detailed view of exploration events throughout the US in 1982.

Jan 5, 1983

By F. C. Appleyard

A couple of miles southwest of the town of Saltville in the western tip of Virginia is a little village called Plasterco. Gypsum has been produced in this area since about the year 1815, being originally found as small outcrops at the surface. Production in the early days was very small, and the use of the mineral was limited to that of "land plaster" or ground gypsum which was spread on the land to sweeten the soil. In the late 1800's, a small calcining plant was constructed and the production of gypsum plaster began. About this same time, the surface rock was depleted and it became necessary to begin underground mining operations in order to maintain a continuous supply of raw material. The United States Gypsum Company became interested in this property in 1909, and has operated there ever since, having enlarged the calcining mill and built a plant for the manufacture of gypsum wall-board in the middle 1920's. Production of gypsum continues from underground' mining operations, and the present mine at Plasterco is now about 1,000 feet below the surface, making it the deepest gypsum mine' in the world.

Jan 1, 1965

By Peter Werner

Technological advances in mine equipment and milling processes have enabled mining companies to exploit ever lower grades of ore. The result has been larger disturbances, greater volumes of waste, a complex web of infrastructure, and an overall trend toward mega projects that can extend over several square kilometers. This explosive growth in a mining operation’s disturbance footprint provokes an obvious question: What is it going to cost to reclaim all of this? At face value, this can be an enormous financial liability for a company, but since the timing of reclamation may be years in the future for many operations, these costs can be heavily discounted, thereby limiting the burden on the corporate balance sheet. Nonetheless, mining companies are eager to remove these liabilities as quickly as possible; conversely, regulators want assurance reclamation will, in fact, occur. How might one bridge these competing interests? Navigating the practical and financial requirements of a post-closure landscape requires foresight, judgement and assumptions; however, companies that do not adequately plan for these future expenditures when there is no offsetting income stream will likely face some difficult decisions. Simple risk analysis tools and utilizing the time value of money can help bring some clarity to this end-of-mine life phase.

Dec 1, 2025

By J. P. Van Dillen

Continuing interest in processes that will effect separations in the fine particle size range has prompted intense interest in the use of high gradient magnetic separation (HGMS) for beneficiation of uranium ores. Some of the uranium minerals are paramagnetic and hence are amenable to concentration by HGMS. This paper presents a brief review of the problems associated with uranium ores beneficiation, a description of the HGNS process, and the effects of the parameters--pulp velocity, field strength, matrix loading and magnetic field gradient on product recovery and grade. Unsatisfactory separation of uranium minerals by HGHS is related to ore specific properties such as lack of liberation, fine dissemination of uranium minerals, uniform distribution of magnetic minerals throughout the ore matrix and interference of micron sized slimes. Experimental techniques to identify and resolve some of these problems are outlined.

Jan 1, 1982

By Dan Ifrim

Soft ground tunneling poses major challenges to the underground industry. Most of soft ground tunnels are in highly urbanized areas, often include limited cover, and include a strong trend of increasing diameters. Therefore, soft ground tunneling works can sometimes cause inevitable ground movements and settlements that may lead to damages to adjacent buildings, roads, structures or utilities; many of these being “lifeline” infrastructure assets. Tunneling operations, Tunnel Boring Machine (TBM) advance rates, and face pressure control can significantly increase or decrease such risks, depending on how well the TBM and operational parameters are applied to the ground conditions. Additionally, the risks of impacting existing infrastructure are heightened in many parts of North America because of cobbles and boulders. To date there is no standardized guideline that determines appropriate tunneling rates nor operator’s guidelines, to ensure safe tunnelling in soft ground. The paper analyzes tunneling records from completed soft ground tunnels to determine a relation between ground conditions, tunnel cover, TBM cutters maintenance and TBM advance rates. The records are discussed to draw several mitigation measures to be adopted during tunnelling, to reduce risks of settlements, over excavation or sinkholes.

Jun 13, 2021

By Carl L. Morris

This short dissertation concerning "what the client expects from the engineer" is directed mainly at the design and construction of metallic ore concentration or beneficiation plants. However, practically the same conditions apply to the design and construction of cement and lime manufacturing facilities, with the exception that the latter facilities reflect the client's and engineer's concepts of customer service and in some cases reflect promotional considerations for the product manufactured and distributed. The client expects his engineering contractor to contribute in an efficient, cooperative, and economical manner current industry-wide know-how and experience to the specific project under consideration through the client's organization

Jan 1, 1969