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By Nick J. Miles, Gareth J. Brown

The degree of fragmentation of dispersed systems of brittle materials such as pulverised rock has been described by a fractal dimension i.e. the fragmentation fractal. This fractal dimension represents a power law size-frequency distribution, where, in this case, the size is defined as the square root of the projected area. The existence of a fractal dimension for the number-size distribution, of the progeny of failure event, is direct evidence for scale invariance of the fragmentation process. Since a fractal dimension infers that failure mechanisms operate on all scales it has been suggested that the fractal dimension is a measure of the fracture resistance properties of materials during fragmentation. In order to investigate this a range of rocks of varying fracture toughness were broken under similar levels of impact velocity in the dynamic tensile failure of single particles. The fragmentation fractals determined from the resultant particle populations, of the breakage experiments, were monitored and are discussed.

Jan 1, 1995

By W. E. Hale

The Institute of Applied Geology (I.A.G.), a joint project sponsored by the University of the Philippines, the Philippine Bureau of Mines and the United Nations Development Programme (Special Fund) undertook during 1965-66 a number of field projects in Northern Luzon Island (Fig. 1). These field operations were of a two-fold nature: during approximately six weeks an orientation survey, involving, geology, geophysical surveying, and geochemical prospecting, was conducted over a partly developed, disseminated copper deposit at Sto. Nino (Fig. 1). The Sto. Nino study demonstrated (Hale and Govett, 19677 Govett and Hale, 1967) the feasibility of geochemical prospecting relative to other exploration methods for the location and delineation of disseminated copper occurrences, the major source of metal in the expanding mineral industry of the Philippines. A vein occurrence at Suyoc (Fig. 1) was similarly subjected to

Jan 1, 1968

By G. J. Lindenburg, T. L. Wilson

The Velvet uranium mine is located in the Big Indian district of the Colorado Plateau. The uranium ore body lies within the lower Triassic Chinle Formation, and the ore is associated with west-south-westerly trending fluvial sand systems. Exploration and mining are directed by longhole drilling and radiometric sampling. Results of the gamma probing, face scanning, and geologic mapping guide mining decisions and planning. Three people are directly involved with the geologic procedures: two geologists and a mine supervisor. The two geologists map, do rib scans, and direct longhole drilling. The third man involved, the mine supervisor, has last minute directive action based on shot hole probe data.

Jan 1, 1992

By G. J. Lindenburg

The Velvet mine is located in the Big Indian district of the Colorado Plateau. The general area, also known as the Lisbon Valley district, is about 65 kilometers southeast of Moab, Utah and about 120 Kilometers southwest of Grand Junction, Colorado. As shown by the slide, the Velvet area is typical of the high desert of the southwest United States. The elevation at the decline collar is 1,967 meters above sea level. To date, the Velvet has produced 1.5 million kilograms of U308 and 2.1 million kilograms of V205. The current production averages over 4,000 metric tons of ore per month. Access to the Velvet mine is by a 1,160 meter long decline. Fresh air is supplied through the decline and a 152 centimeter cased borehole. Contaminated air is removed by two 152 centimeter cased boreholes. The east side of the mine is mined using a conventional room and pillar method; whereas the west side is mined as combination conventional and random room and pillar,

Jan 1, 1983

By W. J. Garmoe

The Carr Fork mine is located approximately 50 kilometers southwest of Salt Lake City, Utah, in the Bingham or West Mountain District, adjacent to the Bingham open pit copper mine. Applied geology at Carr Fork, by Anaconda Minerals Company personnel, includes detailed geologic mapping and sampling of underground workings, logging and sampling of drill core and cuttings, and the preparation and posting of geologic maps and cross sections for geologic interpretation, ore reserve calculation, mine operations, and long range planning. Accurate and easily understood graphic recording of Carr Fork geology is essential for optimum use by operating and engineering personnel. The design and implementation of exploration, development and definition drilling programs, research into geological spatial relationships, and analysis of structural complexities of the Carr Fork deposit are also integral parts of the applied geology program.

Jan 1, 1992

By W. C. Peters

Geologists take the role of mine geologist when they apply their science to the design and operation of a specific minerals project. In doing so, they use the entire spectrum of procedures in economic geology and engineering geology to deal with a specific system of orebodies and associated environment. The objectives are established by stages in the life cycle of a mining operation as it goes from a prospect to a development project and on to a mine. This paper summarizes the elements of a mining geologist's role, with examples highlighted from the preceding papers.

Jan 1, 1992

By R. G. Hite, R. G. Rowe

The Crandon deposit, located in northern Wisconsin, is a 65.8 million ton Precambrian volcanogenic massive sulfide deposit which averages 1.4% copper and 5.8% zinc. The deposit is classic in origin, mineralogy and shape. Comprehensive understanding of the geology of both the deposit and the project site has been fundamental to the credibility and success of project feasibility studies and regulatory permit preparation. Mine development in the current investment and regulatory climate requires thorough and timely application of geologic tools. From 1977-1980 geologic activities were focused on the typical objectives of orebody delineation, reserve estimation, depositional geology, and general site investigation. Results from these programs formed the basis for the project's preliminary feasibility studies. Since 1981 further geologic investigations have provided criteria for project design, site management, and operational permitting. Activities have included mine entry position definition drilling, devel reserve modeling, large diameter (150 mm) core drilling for mill pilot samples, rock mechanics testing, and evaluation of the glacial overburden/deposit geohydrology for computer simulation.

Jan 1, 1992

By Roger G. Rowe

The Crandon deposit, located in northern Wisconsin, is a 65.8 million ton Precambrian volcanogenic massive sulfide deposit which averages 1.4% copper and 5.8% zinc. The deposit is classic in origin, mineralogy and shape. Comprehensive understanding of the geology of both the deposit and the project site has been fundamental to the credibility and success of Project feasibility studies and regulatory permit preparation. Mine development in the current investment and regulatory climate requires thorough and timely application of geologic tools. From 1977-1980 geologic activities were focused on the typical objectives of orebody delineation, reserve estimation, depositional geology, and general site investigation. Results from these programs formed the basis for the Project's preliminary feasibility studies. Since 1981 further geologic investigations have provided criteria for project design, site management, and operational permitting. Activities have included mine entry position definition drilling, developing geostatistical reserve modeling, large diameter (150 mm) core drilling for mill pilot samples, rock mecha¬nics testing, and evaluation of the glacial overburden/deposit geohydrology for computer simulation.

Jan 1, 1983

By Y. Tao

The features of the teeter bed separator and its application in the coarse slime separation of Chengjiao coal preparation plant were discussed. The relationship between the coarse slime separation efficiency by TBS and the particle size were studied, and the influence of using TBS on dense medium consumption and oil consumption were investigated, it increased the clean coal yield and the comprehensive recovery of the whole plant, and brought huge economic benefits to Chengjiao coal preparation plant.

Jan 1, 2011

By Malcolm T. Wane

The subject matter of this paper, "Applied Rock Mechanics?," has its genesis in a recent field trip taken by the author. A more or less standard question asked at the mines visited was "How are you using the principles of Rock Mechanics to assist you in maintaining an efficient, safe, and competitive mining operation?" The question was couched in a number of different forms, but the intent was to determine whether or not a general theory based on reason and the scientific method was applied or whether the alternatives of tradition, intuition, ?common sense', revelation, ?shotgun methods' or authoritarianism were invoked. Perhaps two responses to this query will be illustrative of the general nature of the replies. At operation XYZ an extension to the known ore body has been found. The extension is of large enough size and grade that a mining scheme using load-haul-damp techniques is envisaged. Since this represents a departure from the present mining scheme, questions have arisen regarding pillar sizes, room and entry sizes and possible support requirements. A task force has been set up to expeditiously plan for these things and write the necessary specifications and requirements. The fundamental question was posed to members of this group.

Jan 1, 1971

By Thomas J. Rudolphi

Efficient transport of bulk materials by belt conveyor systems is an important engineering design issue, especially as conveyors become longer and power requirements increase. It is well known within the industry that the parasitic energy loss of a belt conveyor, due to the indentation of the idlers into the belt backing material can be upwards of half the total energy required to drive it on a horizontal flight. Other loss sources includes the rolling resistance of the idlers, belt/roller misalignments, material trampling, frictional and acceleration losses on loading, etc., but energy absorbed by indentation of the belt backing as it passes over each successive idler is the dominant power consuming factor. INDENTATION LOSS MODELS Models to predict the rolling resistance of a cylinder (idler) on a viscoelastic foundation (backing material) have been available for some time. As a contact problem, it is nonlinear (contact length or indentation depth is a dependent on the load and vice versa) in load/deformation response. Rubber backing material is generally assumed to behave as a linear viscoelastic solid, even though it is known that most rubber compounds retain linearity only at very low strains. Because completely general solutions are impossible, practical solutions require simplifying assumptions. Those assumptions relate naturally to two separate pans of any analytical model: I. The deformation model-aspects of the problem relating to the geometry, boundary conditions and kinematics of how the material deforms. 2. The material model-aspects of the problem relating to the material properties, or constitutive relationships, i.e., the stress/strain relationships.

Jan 1, 2008

By Brad Simser

Several case histories from Glencore’s Sudbury Operations show how passive seismic monitoring data is used for geotechnical decision making. The data comes from three different seismic arrays monitoring two open stoping deposits, and a narrow vein cut and fill/blasthole operation. Mining depths range between 1000 to 1680m below surface. The deposits are hosted in hard igneous rocks typical of the Sudbury basin, with characteristically high horizontal stress (approximately 1.8 times the depth of overburden). Rockbursting is the main geotechnical risk, due to the strong brittle nature of the rock and local high mining extraction. Fault related seismicity includes both fault slip events, and the stress channelling effect as the mining front approaches a major fault structure. Planar data trends generally line up with known faults and often indicate early stage fault activation. The structures are risk ranked based on their seismic response. This has been particularly useful at the Nickel Rim South Mine (NRS) where the structural fabric (jointing and small-scale faulting) is generally parallel to the more through going faults. The persistence of structures is difficult to measure, and the NRS faults generally have low offsets and thin gouge. The visual difference between the more persistent structures that occasionally generate large seismic events (up Mw 2.9 to date) and localised joints/slips is often minor. The seismic monitoring data clearly shows the more active structures. This information is highlighted on mine plans to help guide enhanced ground support and seismic re-entry protocol barricade locations. Pillar loading/yielding is a key element to the blasthole operations where a primary/secondary mining sequence is used. The secondary pillars are mined in a yielded state with just-in-time development. An example of the seismic signature of a secondary stope is shown with emphasis on the need for high location accuracy given the stope widths of 12.5 to 15m. The ratio of the shear wave energy to primary wave energy (Es/Ep) has long been used as a method to estimate source mechanisms; the higher the ratio, the more likely the event is fault slip versus rock fracturing. Data sets are filtered on Es/Ep ratios to highlight both fault slip populations and stress fracturing mechanisms. Examples of seismic data quality checks, high stress development, and re-entry protocols are also shown in the case histories.

Apr 26, 2022

By J. W. Merks

Applied statistics provides scores of powerful tests and techniques that are widely used and abused in science and engineering. The variance is the basic measure for variability, precision and risk. The formulas for the variances of the arithmetic mean and the weighted average are derived from the variance of a general function, as defined in probability theory. The requirement of functional or mathematical independence in probability theory translates into the concept of degrees of freedom in applied statistics. Geostatistics is the only variant of statistics in which functional dependence and degrees of freedom are irrelevant. This paper examines whether such basic elements of probability and statistics can be ignored with impunity.

Jan 1, 1998

By J. W. Merks

Applied statistics provides scores of powerful tests and techniques that are widely used and abused in science and engineering. The variance is the basic measure for variability, precision and risk. The formulas for the variances of the arithmetic mean and the weighted average are derived from the variance of a general function, as defined in probability theory. The requirement of functional or mathematical independence in probability theory translates into the concept of degrees of freedom in applied statistics. Geostatistics is the only variant of statistics in which functional dependence and degrees of freedom are irrelevant. This paper examines whether such basic elements of probability and statistics can be ignored with impunity.

Jan 1, 1997

By G. L. Mowrey

One of the critical parameters of any automated coal mining system is the ability to only cut coal and not the rock / waste surrounding it. To do this the system must be able to detect where the coal-rock/ waste interface is. The U.S. Bureau of Mines is investigating a new approach to vibrational coal interface detection (CID) by utilizing an adaptive signal discrimination (ASD) system to perform feature extraction and classification of complex vibrational signals. Accelerometers, geophones, and piezoelectric films are mounted on mining machines and/or strata and are used to monitor vibrations produced during mining operations. Selected data are digitized and the ASD system is trained on known types of vibrations (e.g., "cutting coal" and "starting to cut roof"). A signal classifier is then generated which can be used to identify unknown waveforms. The ASD system can be retrained if mining conditions change significantly.

Jan 1, 1990

An atomic force microscopy (AFM) has been applied to study the adsorption of potassium amyl xanthate (PAX) and potassium ethyl xanthate (KEX) on arsenopyrite surface in solutions. AFM images show that the collectors adsorb on arsenopyrite surface in patches at pH 6. Increasing the chemical dosage will increase the adsorption density of the patches on mineral surface. The increased probe-arsenopyrite adhesion measured in PAX solutions at pH 6 is attributed to the adsorption of the patches, suggesting the hydrophobic nature of the patches, which is likely the oily dixanthogen. It is also found that arsenopyrite is reactive in water in the presence of air. At a high pH with the addition of Ca(OH)2 the adsorption of collectors on arsenopyrite is greatly retarded or depressed because the mineral surface is coated by a lot of precipitates, which is hydrophilic in nature as shown by the measured strong repulsive probe-arsenopyrite detachment force. The findings confirm that the flotation behavior of arsenopyrite in xanthate solutions is very similar to that of pyrite.

Feb 27, 2013

By M. Wiber, P. Nicoll

Rio Algom has embarked on a major programme of expansion with the goal of becoming one of the world’s top-performing base-metal mining and metals distribution companies. To assist the company and its operations in achieving its business objectives, we are implementing an environment, health and safety (EHS) management system, built to be compatible with the 14001 model. We recognize that a sustainable development approach for Rio Algom includes outstanding performance in EHS and community responsibility and is essential to earn acceptance within the communities where we operate or wish to locate; raise capital; obtain permits, and operate efficiently. We are committed to triple bottom line accountability, i.e. full consideration of environmental, social and economic concerns in our business decision making.

Jan 1, 2000

By Tristan Joubert, Fabio Panella, LiLing Chen, Yung Loo, Michael Devriendt, Nasir Qureshi, Ahmad Ali

Tunnel inspections have traditionally been carried out manually by inspectors writing up observations and taking photos of defects. The results from the inspection and the defects observed are dependent upon the rigor of the inspectors and may be subject to repeatability and consistency issues and is often time consuming with elevated health and safety risks. This paper will discuss work that is being carried out in developing and implementing an innovative hardware and software solution integrating machine learning to automate the process of capturing objective tunnel condition information, offering cost and programme savings as well as health and safety improvements

Jun 13, 2023

Application of microprocessors, programmable logic devices, and other computer-oriented hardware and software on-board large surface mining equipment to optimize availability and productivity, stretch machine life, and protect against catastrophic breakdown has been a goal of heavy-equipment manufacturers for several years. Progress in this direction has not been as rapid as many manufacturers anticipated in the mid-1980s, and, on the other side of the coin, mining industry and machine operator acceptance of such products has not always been enthusiastic. However, the trend toward such development seems undeniable. Large surface mining equipment in the future will doubtless carry more, and not fewer, applications of computers and computer-related products. The intensity of development interest and degree of progress in commercializing such on-board computer and computer-related products on surface mining equipment varies considerably among the manufacturers. Summarized here are the on-board computer-oriented products of three heavy-equipment suppliers-P&H Harnishfeger, Marathon LeTourneau, and Haulpak not a comprehensive survey, but, perhaps indicative of the direction such development is taking.

Jan 1, 1990

By Conrad W. Steller

What is the definition of a successful construction or development project? It could be described in many ways: a project that performs as designed; a project completed on time, a project completed within budget. The title of our talk today is, "The Advantages of Applying Design/Build -Construction Management to the Mining Industry." As our talk develops, you will see that rather than tell you how to apply this concept, we will discuss the advantages and details of Design/Build so that you can independently apply the concept. Design/Build is not new, and it cannot be universally applied. It has, however, within the past ten years, carved a specific and substantial place in the overall construction -development market. The reasons for its rather recent rise to considerable prominence as a concept is due, in part, to the increasing urgency of gaining productive access of a production facility and, in part, to the inherent advantages of the concept's economics--and they are considerable. If the Design/Build concept of contracting were fully understood, it would, without exception, be the favored way for private industry to contract for its new construction and development as well as renovation work. The basic advantages are: earliest possible access and completion at the lowest cost. Design/Build is often equated and compared to "fast track" or "turnkey" methods of construction. The Design/Build concept can, in fact, be both of these or neither. "Fast track", in and 6f itself, implies that the project will be phased construction, that is to say, it will be built quickly; whereas I "turnkey" is a measure of the completeness of the project, usually meaning essentially that the

Jan 1, 1977