Search Documents

By E. W. Davis

This paper deals with the role of the Maintenance Department in a milling operation; specifically, the Mines Development, Inc., processing plant at Edgement, South Dakota. The goal of very maintenance department is the smooth and uninterrupted operation of the plant it serves, To achieve this goal, maintenance men adapt various features and procedures into a program designed to fit the characteristics of their particular plant operation. A few of the basic elements of a sound maintenance program are: 1, A periodic preventive maintenance schedule. 2, A systematic inspection and lubrication procedure. 3. A training program for maintenance personnel. 4 A good equipment-history file system, 5. A carefully planned spare parts inventory.

Jan 1, 1962

By B. Denby, D. J. McMlarnon

During the ongoing research into the possible applications of Virtual Reality in underground operations, the AIMS Research Unit has developed a user-interface driven program which enables a user to input the geometry of underground mines, and add equipment and working processes in order to produce an accurate simulation of their operation. This paper describes the main features of this system (VR-MINE). Virtual Reality is a field which has grown out of three dimensional computer graphics techniques, and allows a user to move freely around a model held within the computer's memory. Movement around this model is carried out by the use of intuitive peripherals such as joysticks, with the user's view from their position within the model being produced in real time on a computer monitor or other device (such as a headset). This enables a user to interact with any three dimensional model and see the results of their actions immediately. VR-MINE is broken into two separate programs, both running under Microsoft Windows 3.1 or above. The first, the editor, allows the user to develop the mine layout and add equipment and personnel. The mine geometry is considered to be made up of various types of objects, for example a straight roadway segment which can be inclined, a junction roadway segment, and a turning segment. The geometry can then saved into a file to be loaded in by the second program of VR-MINE, the viewer. This generates a real- istic representation of the mine, with undulating floors and walls. It also has the ability to display multiple windows on the mine at the same time, which are arranged interactively. The simulation occurs within this program, with the user traversing the model in real time to examine possible areas of improvement in operations. This paper gives a number of examples of how the AIMS Re- search Unit has applied this technology to a range of underground mining scenarios to improve the safety of workers in the under- ground environment. The application discussed include computer graphics and Virtual Reality systems to training, risk analysis, visualisation, simulation, accident investigation and major hazard planning.

Jan 1, 1996

By C. P. Mangelsdorf, Richard A. Allwes

At the request of the U.S. Department of Labor, Mine Safety and Health Administration (MSHA), the U.S. Bureau of Mines evaluated the suitability of using tri-sets for protecting mine personnel in roof-fall prone areas. A steel-set arch provided by MSHA served as a basis for evaluating the performance of the tri- set. All tests and analyses were conducted according to the arch canopy test and design procedures developed by the Bureau. Theoretical resistance functions were established for the steel-set arch and tri-set and were representative of their experimental behavior. The resistance functions were used to determine the energy absorption capacity of the structures and to predict their dynamic response to impact loading. The dynamic tests demonstrated that the arch canopy design procedure is appropriate for tri -sets and yields conservative designs for both steel-set arches and tri-sets. As a result of this work, it is recommended that tri-sets may be considered for protection against roof falls, provided that the arch canopy design procedure is utilized for each application and that the principles underlying the design procedure are understood.

Jan 1, 1992

By Edward C. Dowling

The advance of science and technology influences the modern economy in countless ways. Older industries must adapt to changes in the marketplace, while new industries are born by applying new technology to meet consumer needs. In light of declining head grades and increased unit costs in the US minerals industry, new technological developments in the production environment are paramount to maintaining a competitive footing in the international marketplace. Micro-engineering research provides the transition between the knowledge base and the application of new technology on the production level. Economic considerations The primary goal of technical development in the production environment is to reduce unit operating costs. Simply stated, this is accomplished by improving operating efficiencies and productivities on the production level. The goal of micro-engineering research in the production environment is to evaluate promising technologies and develop the criteria necessary to apply them in operations. As such, this process is the first step toward innovation and discovery. Generally, the micro-engineering research is followed by macro-engineering development. In the production environment, there are generally more development projects than can be accomplished in a timely manner. Usually, this is the result of financial and human resource limitations. Consequently, it is necessary to prioritize the work such that the most beneficial projects are accomplished first. By performing a discounted cash flow analysis and using benefit-cost ratios (for non-mutually exclusive alter¬natives) or net present value criteria (for mutually exclusive alternatives), the projects can be rated from best to worst. In this way, the financial and human resources can be best allocated to first complete those projects giving the highest returns before moving on to other activities. Moreover, this information is a prerequisite for management to justify additional financial or human resources.

Jan 1, 1992

By Jr. Winters

The United States continues to be the largest producer and consumer of copper in the world. Table 1 on the following page shows several production statistics for 1974, the most recent year which the non-communist world copper industry might consider a good year, and for 1976 and 1977. In 1974 an estimated 24 percent of the non-communist world's newly mined copper was mined in the United States, and. 87 to 89 percent of that was from the western porphyry coppers. In 1976 U. S. new mine production was down to 22 percent of the non-communist world's newly mined copper, and the percentage of U. S. new mine production supplied by the porphyry coppers had risen to 89 to 91 percent. In 1977 the statistics remained the same as in 1976. U. S. porphyry copper production represented about 65 percent of U. S. refined copper consumption in 1974, rose to 75 percent in 1976, and dropped back to 61 percent in 1977 as imports of foreign copper into the United States began to swell.

Jan 1, 1978

By S. Gundiah

Preparation of functionalized polymers from the polymerization of monomers and preformed polymers are discussed with a few illustrative examples. The methods of their characterization, with reference to their application in flocculation, are described.

Jan 1, 1987

By I. Iwasaki

As the world tension relaxes and as the interest and taste for consumer products change, complacency is beginning to prevail over the needs of minerals and primary metals. The current trend towards resources and energy conservation calls for miniaturization of consumer goods, and lowers the demand for virgin materials to produce goods and services. Challenged by the third world countries with high grade ores and low labor costs, industrialized nations with lower grade ores are being pressed into more efficient operation through technological innovation, while protecting the environment. In many countries, domestic mines were forced to close since the oil crises due to rapidly rising energy and labor costs. Research in conventional mineral processing needs to be directed towards breakthrough technologies in order to maintain the competitive edge in the global marketplace. Research activities will provide new challenges in the processing of solid waste and waste water for environmental remediation as well as for resource conservation, in the preparation of new functional materials of extreme purity and/or unique properties for high technology applications and in the development of such future resources as deep sea minerals and extraterrestrial materials.

Jan 1, 1995

By J. A. Cremeens, D. D. Overton, J. C. Varnier

"Slope failures that occurred in 2008 and 2009 at the Pikeview Quarry in El Paso County, Colorado, USA were investigated using three-dimensional discrete element modeling methods. Large scale block sliding failures occurred along weak bedding planes that dip steeply into an excavation located at the toe of the slope. Several mining sequences at the toe of the slope were simulated to evaluate the effects of various degrees of extraction and backfill on slope stability. Slope stability back analysis was conducted using pre-failure and post-failure conditions to determine the joint shear strength properties. Laboratory testing was also conducted to determine intact rock properties. Three-dimensional discrete element analysis was uniquely applicable to this evaluation because it allowed representation of shear stress of the basal sliding surface and it afforded evaluation of several scenarios of extraction and backfill at the toe of the slope. INTRODUCTION The Pikeview Quarry is an aggregate quarry located approximately five miles northwest of Colorado Springs in El Paso County, Colorado, USA. The quarry has been operated by several owners since the early 1900s. The Pikeview Quarry has been a major source of construction aggregate for the Colorado Springs area for many years (MSHA 1986). In the 1950s, the site was mined by Peter Kiewit and Sons to provide limestone for the construction of the nearby Air Force Academy. A large scale slope failure occurred on December 2, 2008, which stopped mining activity at the Pikeview Quarry. A second, related slope failure occurred on September 13, 2009. The second slope failure was located immediately adjacent to the initial December 2008 failure. The objective of this publication is to discuss the three-dimensional slope stability evaluation. The causal relationships of slope instability are not within the scope of this publication. However, omitting the precursors to slope failure would limit understanding of the nature of the slope stability evaluation. The regional and local geology and the history of slope instability at the Pikeview Quarry aid in understanding these precursors. Two main failure mechanisms were hypothesized during the failure investigation to explain the triggering of the 2008 and 2009 large slope failures at the Pikeview Quarry. Both mechanisms are given equal credence in this publication. Quarry excavation was a key factor in the slope instability for both failure mechanisms. The objective of the three-dimensional model was to evaluate the effects of extraction and backfill at the toe of the slope with respect to slope stability. GEOLOGY Regional and local geology are both important factors in slope instability at the Pikeview Quarry. Geologic structure at the quarry is related to regional mountain building and basin development associated with the Laramide Orogeny and the Rocky Mountains. Lithologies at the Pikeview Quarry are also related to regional trends. Localized geologic features, primarily related to weathering and erosion, have also been major contributing factors to slope instability at the Pikeview Quarry."

Jan 1, 2017

By Robert M. Cox

A thorough geological engineering investigation is required before surface lands overlying abandoned underground mines can be safely recommended as building sites. The major problems confronting the geological engineer are assembling accurate geologic and mining information and developing an accurate rock mechanics model of the situation. A successful investigation requires a combination of technical expertise in rock mechanics and engineering geology tempered with practical engineering judgment. The results of a good study are not always favorable to the prospective builder.

Jan 1, 1975

By Nasib Al Habib, Hooman Askari-Nasab, EUGENE BEN-AWUAH

In-pit crushing and conveying (IPCC) is getting popular in deeper open pit mines as a suitable alternative to truck haulage because it offers a lower operating cost due to shorter haulage distance and less truck requirement. Semi-mobile in-pit crusher, currently the most popular IPCC system, is relocated every two to five years, and the short-term plan needs to be updated accordingly. To the best of our knowledge, short-term planning with IPCC is an area of research that has yet to be explored extensively, and hardly any model can generate a shortterm extraction sequence considering an IPCC. This research work proposes a mixed integer programming model to develop a short-term production plan within a time horizon of 12 months. The model's objective is to optimally allocate shovels to minimize the cost of material handling and maximize revenue subject to meeting plant requirements, maximum allowable tonnage variation and IPCC location constraints to achieve production and NPV targets set by the strategic plan. The proposed model will be implemented in an iron ore mine case study for verification. The model is developed and solved using MATLAB. The comparison of results between scenarios with and without IPCC justifies the use of IPCC in large open pit mines from a short-term perspective.

Jun 25, 2023

By D. W. Fuerstenau

The flotation behavior of quartz in the presence of alkyl ammonium acetates as a. function of alkyl chain length has been interpreted in terms of hemi-micelle formation at the solid-liquid interface. The van der Waals cohesive free energy that is responsible for hemi-micelle formation has been found from these results to be 1.02 kT per CH group. This 2 is in excellent agreement with literature values obtained from research on the properties of micelles in bulk systems.

Jan 1, 1964

By J. M. Mutmansky, B. Kolonja

A PC-based simulation model using the software packages SIMAN and CINEMA was developed to simulate and animate truck-shovel operations. The model is capable of simulating one mathematical dispatching strategy using linear and dynamic programming and six heuristic dispatching strategies. Data were collected from an actual operating mine through time studies and analysis of historical records. Statistical analyses were performed, and appropriate theoretical distributions were fitted for various time events in the truck-shovel cycle. The model was then applied to study overall impact of these dispatching strategies on constrained and unconstrained mine productivity. The simulation/animation model developed in this study seems to be an efficient planning tool for choosing optimal fleets and finding an optimal dispatching strategy to produce an equilibrium between the quality and quantity of production.

Jan 1, 1995

Table A. Conversion of English to SI Units Table B. Strength Properties of Rocks Table C. Engineering Properties of Rock Table D. Properties of Common Minerals Table E. Material Properties and Characteristics Table F. Heat Value of Various Fuels Table G. Geometrical Relationships and Mensuration Formulas Table H. Standard Sizing and Meshes Table I. Ship Measures Table J. International Atomic Weights Table K. Time Value of Money Factorsfor Discrete Compounding

Jan 1, 2008

By Andrew Thomson, Peter Wright

"A section of a London Underground expanded segmental lined tunnel constructed in the 1970’s progressively deteriorated after 2001, with extensive radial joint spalling and mid-segment cracking. As part of the PPP contract Tube Lines Ltd and their partners carried out various analyses of the tunnel, including analysis of laser scans of the tunnel, geotechnical testing through the tunnel walls, geotechnical desk studies, real-time monitoring and even full-scale segment testing. This paper discusses the behaviour of the tunnel lining in this setting, the causes of failure and the lessons that can be learnt from this rare example of a tunnel which was progressively failing in service. It is finally noted that a replacement tunnel lining was installed during night-time possessions and completed in 2015. INTRODUCTION In 2003, Tube Lines Ltd. was established under a Public-Private Partnership (PPP) scheme to provide maintenance services and upgrade projects for London Underground (LU). The Deep Tube Tunnel Knowledge and Inspection Programme comprised the assessment of all tunnels, shafts and other underground structures. This included a number of lengths of tunnel constructed using segmental concrete linings. First used by LU in the 1960s, the savings both in cost and speed of construction led to concrete linings replacing cast iron for new tunnel construction in all but a few cases. During the initial scoping phase of this programme, inspections identified potential issues with the expanded concrete segmental linings on the Jubilee line. The inspections found a number of segments with surface spalling (Figure 1a), which did not appear on the post-construction defect records. These were generally relatively shallow, up to 40mm deep, spread over a wide area of segment. These were different to spalls caused by handling damage, which are typically localised at segment corners. Subsequent inspections over the following years identified an increasing number of segments with these types of spalls as well as an increased incidence of longitudinal mid-segment cracking (Figure 1b). The increasing occurrence of these defects was hypothesised to be caused by tensile stresses developing in the vicinity of the joint."

Jan 1, 2016

By W. H. Wilson, G. Bjarnholt, D. C. Holloway

This paper describes the results of field tests conducted on a 5x25m bench face to evaluate several new concepts for improving smooth wall blasting. These ideas involved the use of notched boreholes to direct the fractures and unconventional types and placements of explosives. The notches were made with a mechanical broaching tool, a water jet and with shaped charges. Borehole pressures were measured with an inexpensive and expendable pressure transducer developed for this program. The testing showed that at hole spacings 38% greater than normal practice, notched holes with half the normal loading density produced equivalent results.

Jan 1, 1986

The exploitation of mineral deposits for economical recovery of the contained minerals has many aspects differing from other industrial or manufacturing operations. However, generally accepted principles of good organization and management applicable to industrial plants are similarly effective for mineral processing plants. A more detailed coverage of organizational structures and management techniques than is possible in this section can be obtained from many good books devoted wholly to these subjects. A few of the more readily available examples are included in the general references at the beginning of this section. The field of mineral processing encompass a wide variety of minerals, processes, flowsheets, equipment, and end products. Mineral deposits, mines, and related beneficiation plants are found in all parts of the globe, often in remote locations with no nearby support for supplies and maintenance. Available labor is frequently unskilled, sometimes primitive, and often untrained without machine and hand tools or heavy equipment experience. Such situations call for well- planned and conducted training programs covering the full range of mining-type job skills. Climates can range from arctic to tropical and from arid to extremes of rain or snow, and the mine and plant sites can be almost anywhere. However, it is often possible and sometimes necessary for

Jan 1, 1985

By J. L. Francke

This paper describes the practices and methods used in a study of Time Domain Reflectometry (TDR) as an inexpensive deformation monitoring tool in underground excavations at the Waste Isolation Pilot Plant (WIPP). The WIPP is being developed near Carlsbad, New Mexico, for the disposal of transuranic nuclear wastes in bedded salt 655 m (2 150 ft) below the surface. Data collected from WIPP geomechanical monitoring are used to characterize conditions, confirm design assumptions, and understand and predict the performance of the deep salt excavation. The geomechanical monitoring program encompasses numerous geomechanical monitoring techniques ranging from inspection of observation boreholes to advanced radar surveys. In 1989 TDR was introduced as a monitoring tool with the installation of 12.7 mm (0.5 in) diameter TDR cables in the underground excavations. In 1993, a new TDR system was installed in a separate location. Based on experience with the previous installation, enhancements were implemented into the new TDR system that: 1.) extended the period of performance by increasing cable diameter to 22.2 mm (0.875 in), 2.) increased accuracy in locating areas of deformation by aligning cables with nearby observation boreholes, and 3.) improved data acquisition and analyses using a standard laptop computer, eliminating the chart recorder previously used. In summary, the results of a correlation between the TDR signatures to nearby observation boreholes and geomechanical instrumentation will be presented.

Jan 1, 1996

The introduction of nitro-carbo-nitrate (NCN) blasting agents has been one of the most significant innovations in the explosive industry in the last twenty years. The most commonly used blasting agent is a rather narrowly proportioned mixture by weight of 94% ammonium nitrate (AN) and 6% No. 2 diesel fuel oil (FO) that is generally designated as ANFO. Other formulations have been developed but none of these have been as extensively used as ANFO. The relative safety of the nitro-carbo-nitrate (NCN) blasting agents almost immediately suggested bulk loading techniques to obtain economies in materials handling. The first attempt at bulk handling was to pneumatically load boreholes with ANFO. When the initial experiments were made in 1957, it was apparent that there were three problem areas which needed study to minimize potential hazards. These were: 1. Static Electricity 2. Fumes 3. Safe Handling Procedures Since those early days, considerable work has been performed in evaluating these problem areas and in arriving at procedures and recommendations that would provide the required safety. Despite the relative insensitivity of ANFO type products, all normal practices for the safe handling of explosives should be obselved. Smoking should not be tolerated in the vicinity of blasting agents and misfires should be handled in the same manner as a misfire with a dynamite charge. The purpose of this Technical Report is to discuss the problems of static electricity and fumes and the solutions that have been developed. Safe handling procedures have been discussed by the Bureau of Mines and are specified by various state and local regulations. Since regulations vary from state to state, the local, applicable regulations must be followed within the area of their jurisdiction. General information is contained in a U. S. Bureau of Mines report, IC 8179, "Safety Recommendations for Sensitized Ammonium Nitrate Blasting Agents" (1963).

Jan 1, 1973

By S. C. Tadolini

The use of resin-grouted cable supports to control large ground movements in several types of underground mines has increased substantially since being introduced in 1991. Cables offer several advantages over traditional support systems, having large support capacities coupled with the flexibility to be used in low openings. Cable slings have been designed to be installed on-cycle using no-spin technology or a two-piece unit that can be placed with hand-held drilling equipment. Additionally, yielding cable supports have been developed and are being used to control large amounts of movement in coal and evaporite deposits.

Jan 1, 1998

By Rakesh Sehgal, Pushkar Verma, Mohit Sharma

"SJVN Limited successfully commissioned its Rampur HEP (412 MW) in 2014. The project has been planned to operate in tandem by directly utilizing the Tail Water of SJVN’s prestigious Nathpa Jhakri Hydro Power Station 1500 MW located upstream. The initial filling of voluminous water conductor system of RHEP with 10.50 m diameter, 15 Kilometer long Head Race Tunnel, involved more than 1.5 million m3 of water. The filling operation of such a large diameter tunnel constructed in young folded Himalayas which always offer less ideal sites for tunnelling and their subsequent operations under pressurized conditions is worth sharing with tunnelling fraternity. The paper covers meticulous planning, execution, precautions taken, and performance monitoring during filling process keeping in view the fragile geology, low rock cover zones, shear zones in close vicinity of thickly inhabited areas, squeezing zones, hot water zones encountered during excavation.1.0 RAMPUR HYDRO POWER STATION IN BRIEFRampur Hydroelectric Project (412 MW), is located in Himachal Pradesh (India). This project is a downstream development of Nathpa Jhakri Hydro Power Station (1500 MW) constructed on river Satluj and commissioned during 2003. Both the projects today are now successfully working in tandem. The upstream NJHPS has been constructed on the left bank of the river while the downstream Rampur HPS is located on right bank of the river (Figure-1).The major length of HRT of Rampur project lies on right bank of river before it crosses under the river in its initial reach (Figure-2). The main features of the project are as below:• 10.50 m diameter 15 km long HRT ending in a 155.75 m deep, 38.00 m diameter surge shaft.• 3 steel lined pressure shafts, 5.4 m dia, 211-220m long.• Surface valve house 69 m long x 10.50 m wide x 23 m high housing 3 No. butterfly valves• 3 No. surface penstocks 5.4m dia 368-382m long, bifurcating into six penstocks, each of 3.80 mdia. to feed six generating units of surface power house 158 m long x 24.50 m wide x 48 m high, with Francis turbines each of 68.67 MW capacity."

Jan 1, 2016