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By K. Duckworth

"Comparative tests of the conventional Turam survey configuration and an alternative configuration called the Tx-parallel configuration were conducted at the McClean uranium deposit in northern Saskatchewan. Both configurations detected the known conductors at the site but the alternative configuration demonstrated its particular effectiveness in the reconnaissance role. This effectiveness results from the fact that the length of Tx-parallel traversesis controlled only by the length ofthe transmitter and not by its power. In addition, the field strength along a Tx-parallel traverse is uniform unless the traverse approaches the end of the transmitter. This freedom from a strong gradient of the primary field along a Tx-parallel traverse eliminates the gradient-induced anomaly shifts which are common in conventional Turam operations. The locations of each of the McClean conductors, that were obtained from the Tx-parallel profiles, werein better agreement with the locations known from drilling than were the locations obtained from the conventional profiles. However, the conventional profiles gave better estimates of the conductance of the targets.The results obtained over the McClean conductors indicate that current gathering has a strong influence on Tx-parallel results with consequent unpredictable influence on depth and conductance estimates. However, the depth estimates obtained from the Tx-parallel data appear to be in good agreement with the known depth of the McClean south conductor. The Txparallel results provide shallow estimates of the depth of the McClean north conductor which suggest that the fracture zone above the graphitic conductor is a significant conductor as was also suggested by earlier VLF surveys.Comparison with the wide range of published geophysical test surveys for the McClean site showed that apart from the work required to lay the transmitter, the Tx-parallel mode of operation of a Turam exploration system is operationally very similar to a moving source Slingram type of survey. At the McClean test site, it provided the same depth of exploration as a conventionally deployed fixed loop transmitter."

Jan 1, 1988

By K H. Esbensen, K Engström

The conclusion from the debate over the last decade in the mining sector is that, for grade control, reverse circulation (RC) drill sampling gives more reliable results due to less sampling problems than blasthole samples. However, by conducting the latter with well-controlled procedures there still exist fair possibilities to counteract the major blasthole sampling problems and achieve fit-for-purpose representativeness, especially if based on minimal loss of fines. In the present PhD study, extensive replicate experiments and variographic characterisations are conducted to evaluate the performance of manual blasthole (BH) sampling and sectorial segment sampling. The experiments were performed in Luossavaara-Kiirunavaara AB (LKAB)’s Leveäniemi open pit mine in the north of Sweden. The experimental area is an apatite-magnetite iron ore deposit of the Kiruna type, with the demand to exhibit a maximum of local heterogeneity to allow the experiment the largest possible conclusion powers. Gathering and splitting the complete BH drill cutting cones (fines cone, coarse cone) served as an authoritative reference on which to assess the representativity of the two BH sampling methods.Results show that manual BH drill sampling is able to produce samples with an acceptable accuracy and precision if performed properly and with insight. Based on variographic comparison, segment sampling shows similar precision for chemical grades as the manual sampling, while the particle size distributions were more deviating for segment sampling than for manual sampling at the high and low size ranges. Possible reasons for these partly surprising results are discussed.For further investigation of the performance of BH versus RC drill sampling, a second experiment has been planned on a parallel profile. This will result in an unprecedented opportunity for a full variographic comparison between RC and BH sampling, aimed at designing specific, fit-for-purpose sampling procedures as a function of ore quality, cut-off grades and important contaminant levels.CITATION:Engström, K and Esbensen, K H, 2017. Blasthole sampling (replicate and variographic experiments) in LKAB open pit iron ore mines – fit-for-purpose representativity?, Australia, in Proceedings Eighth World Conference on Sampling and Blending , pp 85–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The success of smooth blasting essentially depends on geological condition of rock. Also, in the perimeter hole, borehole pressures with light, well-distributed explosive loads are important to minimise overbreak. In order to simulate perimeter holes with scaled model test, the borehole pressure was considered as a factor of scale. Hydraulic oil pressure is applied as borehole pressure instead of using explosives and detonators in order to remove the undesirable effects of detonators in an experimental set-up of just two perimeter holes in a tunnel blast. The borehole pressure on a perimeter hole is nearly reproduced with hydraulic pressure which is generated by non-electric detonators in the hermetical cylinder.

Dec 6, 2010

Many mines in Canada, the US and S. Africa are reaching the hoisting limit. Very little payload will be possible without compromising safety due the excessive weight. It has been suggested (DeLorme, 2000), that one of the most attractive concepts to enable deeper hoisting is to reduce the allowable factor of safety in the wire rope. Researchers at the Spokane Research Lab are developing new technology to improve hoisting safety and productivity by providing new monitoring and analytical tools. A Shaft Conveyance Monitoring System (SCMS) has been developed which determines hoist rope end load, true conveyance position and acceleration, and rope safety factor, as well as other hoist operating parameters. This information is transmitted to the hoist operator display 20 times per second. Recent field measurements on 45 mm(1 ¾ in.) diameter hoist rope indicate that dynamic forces during loading of a 9000 kg(10 ton) skip may exceed the safety factor of the rope. To improve on the current understanding of the mechanical behavior of hoist ropes, and to help interpret the results from field-testing of the SCMS, a new approach to computer modeling of stranded wire rope is also being developed. Particle Flow Code, PFC3D (Itasca 1995b) is used to simulate the structural behavior of wire rope and the interaction between individual strands when the rope is subjected to static and dynamic end loading. Details of the SCMS, field results from the measured rope loads, and the results of numerical modeling on the wire rope will be discussed.

May 1, 2002

By V. J. Sopuck, O. P. Lavin, Ian Nichol

"A major challenge of contemporary exploration geochemistry is the development of procedures that can locate blind mineralization or mineralization that sub-crops below a cover of transported overburden, the composition of which bears no relation to the underlying mineralization. Over the past few years, the possible existence of diagnostic geochemical features in the country rock associated with volcanogenic massive sulphide deposits has attracted increasing attention both on the local mine scale and on the regional scale. In the present investigation, the nature of the geochemistry of a number of Archean greenstone belts of the Canadian Shield is examined to determine the feasibility of distinguishing productive from non-productive areas of copper-zinc mineralization. The results indicate that productive areas are distinguishable from non-productive areas providing consideration is given to the effects of igneous differentiation on rock compositionIntroductionArchean massive sulphide deposits are an important source of copper and zinc, and to a lesser extent silver and gold, particularly in Canada. As in the case of most other forms of mineralization, there is a continual need to develop new techniques that will improve the chances of success in the search for these deposits. The majority of Archean areas in the northern latitudes are overlain by a variable cover of glacial overburden. Considerable progress has been made in the development of new geochemical exploration techniques for use in glaciated terrain, based on the detection of anomalous dispersion in the glacial overburden. In certain situations, however, as in the search for blind deposits or in areas covered by glaciolacustrine deposits, overburden geochemistry offers little hope for success. In the case of massive sulphide deposits, one possible solution may lie in the detection of anomalous geochemical signatures in the bedrock. Recognizing this possibility, attention has been directed to the investigation of the nature of lithogeochemical dispersion associated with massive sulphide deposits on both regional and local scales, to establish the potential of lithogeochemistry as an aid in the search for these deposits."

Jan 1, 1980

By J. P. Rider

Operating practices and resulting production from longwall faces are continually improving. Consequently, longwall operators are continually seeking to improve the dust control capabilities on longwalls. The National Institute for Occupational Safety and Health (NIOSH) has been conducting dust surveys at longwalls throughout the country in an effort to document the types of controls that are being used and to quantify the relative effectiveness of these controls. To date, surveys have been completed at longwalls in Alabama, Colorado, Pennsylvania, Utah, and West Virginia. In addition NIOSH has been reviewing longwall dust parameters provided by mine operators to MSHA to assess the status of dust control technology being used throughout the industry. Results from the underground dust surveys and information obtained from MSHA will be summarized in this paper to provide an update on longwall dust control technology and practices.

Jan 1, 1963

By Elizabeth M. Smith

The kcICON design-build project in Kansas City, Missouri includes widening the existing roadway, improving interchanges and grade separation bridges, and replacing the Missouri River Bridge. The Missouri Department of Transportation (MoDOT) typically utilizes steel H-piles and steel pipe piles as driven pile support for bridges. After bidding the kcICON project, the cost of steel rose significantly and the design-build contractor used an innovative approach to reduce foundation costs without significantly affecting the project schedule. The kcICON team conducted a value engineering evaluation of alternative foundation types for use at four grade separation structures. The result of the value engineering evaluation was selection of precast, pre-stressed concrete (PPC) piles as the preferred foundation alternative. Terracon developed a test program to evaluate the performance, capacity, and suitability of PPC piles at the site using a PDA and CAPWAP analyses. This paper presents the value engineering design, rationale for selection of PPC piles, results of the pile test program, and findings during production pile driving. The collaborative approach to the project by MoDOT and the kcICON team, combined with testing and a site-specific design approach, resulted in substantial savings for the design-build contractor.

Jan 1, 2009

The basic objectives of mine roadways are to provide sufficient cross sections in order to meet the needs of accommodation of equipment, transport, personnel travel and ventilation. However, many roadways become damaged to the extent of needing maintenance, generally dinting, and in some cases requiring re-ripping. The damaging of a roadway is a result of several factors including geological properties of surrounding strata, method of roadway formation, type and spacing of support and so on. Among these factors, strata conditions play an important effect on the stability of roadway. Weak rocks cause excessive roadway closures and water softens some rocks and promotes the closure problem. In this paper, a scientific discussion on the effect of water on the stability of roadways is given on the basis of results obtained by means of in-situ investigation and laboratory rock tests.

Jan 1, 1996

In presenting this address I am conscious of the honour that has been paid me in my election to this important office, and I am very aware that I follow, in the position of President, many distinguished men who have led the Institute over the 70 years since its inauguration in Broken Hill in 1893.It is perhaps appropriate tonight that I intend to talk about a metal which recalls the birth-place of the Institute, and is also one with which I have had a direct association throughout the whole of my working career. This metal is Silver.Silver is associated traditionally in everyone's mind with money and silverware, and has always been prized for its natural beauty and elegance. It is today one of the few metals in which world consumption has outstripped production, and the events which have occurred to bring about this situation make an interesting story.In telling this story, I propose firstly to indicate our development as a silver producing country, give an historical review of the metal, trace its use as currency and the factors influencing its price, and then say something of the old and new uses of silver. Finally I shall give some comments on silver production in Australia today.Australia, with 6-5 per cent of the world's output of silver, ranks sixth among the producer countries and over the years has contributed 892.5 million ounces to the world's supply which, based upon production since the discovery ofAmerica, is estimated to have been 22,150 million ounces or nearly 680,000 tons.Although our production appears relatively small by...

Jan 1, 1963

Jan 1, 1966

By E. S. Leaver

The gold that is not recovered by a particular process is refractory to that process. A study to determine how the refractory gold is associated in the ore constituents usually indicates the needed improvement in the process or additional methods for bettering recovery. In preliminary work, segregation of the various minerals, gangue or impurities, and data showing the reactions of each in the recovery method readily confines the refractory gold to a certain part on which extensive research can be directed. In this dissecting plan, the microscope is an important aid in locating the refractory gold but should be supplemented by chemical tests.

Jan 1, 1934

By F. H. Buchella, J. F. Buchanan

The San Manuel copper deposit is located about 45 miles northeast of Tucson. The concentrator, smelter, administration building, and other plant facilities are located about seven miles southeast of the ,nine area at the new town of Sari Manuel as shown on Figure 1 (Sketch).

Jan 1, 1961

By F. D. DeVaney

Manganese-bearing deposits f the Leadville, Colo., district are of two distinct types. Manganosiderite, a combined or intimately mixed ferrous and manganous carbonate, occurs in unaltered zones as the predominant mineral. From 50 feet below the surface to as deep as 900 feet, psilomelane and wad, both black manganese oxide minerals, are found in intimate contact with hematite and limonite. A typical analysis of the black oxide ore shows 20.08 percent Fe, 18.64 percent Mn, 15.91 percent insoluble, 14.91 percent moisture, 0.94 percent Zn, and 2.13 percent Pb. A considerable tonnage of the oxide ore has been mined for production of spiegeleisen and for other purposes.

Jan 1, 1940

By F. D. DeVaney

Manganese-bearing deposits of the Leadville, Colo. district are of two distinct types. Mangano siderite, a combined or intimately mixed ferrous and manganous carbonate, occurs in unaltered zones as the predominant mineral. From 50 feet below the surface to as deep as 800 feet, psilomelane and wad, both black manganese oxide minerals, are found in intimate contact with hematite and limonite. A typical analysis of the black oxide ore shows 20.08 percent Fe, 19.64 percent Mn, 15.91 percent insoluble, 14.91 percent moisture, 0.94 percent Zn, and 2.13 percent Pb. A considerable tonnage of the oxide ore has been mined for production of spiegeleisen and for other purposes.

Jan 1, 1940

By James Ridenour

This report represents the first comprehensive accounting of lode mining sites in the Loon Creek mining district, Custer County, Idaho. Thirty-five mine and prospect locations have been added to the Bureau's Mineral Industry Location Subsystem (MILS) data base as a result of initial phases of a mineral appraisal of the River of No Return Wilderness; previously known locations were field checked and the updated information added to the data base. The district's major deposits are gold-copper-silver fissure-fillings hosted by biotite schist intruded by dikes ranging in composition from rhyolite to lamprophyre. These deposits contain a trace element suite similar to Tertiary pink granites and may be related to intrusion of the nearby Casto pluton. Continued firm gold prices could stimulate the search for precious metal occurrences in this and other mining districts in central Idaho.

Jan 1, 1983

By K. S. McClure, S. B. Chitralekha, R. B. Gopaluni, Chmylek. T., S. L. Shah

This is a tutorial paper on industrially successful approaches for nonlinear process monitoring. Online process monitoring is essential to continuous operation of plants at high efficiency. The problem of process monitoring is one where an impending but undesirable process condition has to be identified and used to alert process engineers. This problem has traditionally been solved by practicing engineers using statistical techniques that detect a change in the underlying correlation structure of process variables. For linear correlation structures, algorithms such as principal components analysis, independent component analysis and partial least squares have been proposed. However, many industrial processes exhibit nonlinear correlation structure between the process variables. In this tutorial we describe various nonlinear monitoring techniques and elaborate on two recently developed methods, namely Support Vector Machine and Local Linear Embedding. The two methods are evaluated by application on two experimental case studies, a SAG mill and a polymer extruder.

Jan 1, 2014

By W. W. Adams

"The ninth yearly National Safety Competition covering the calendar year 1933, conducted by the United States Bureau of Mines, w participated in by 332 mines and quarries situated in 35 States. Enrollment represented as increase of 10 plants over 1932, and one addition was made to the number of States represented.The primary purpose of the United. States Bureau of Mines in conducting the contest is to promote safety in United States mineral industries. This purpose is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive recognition on a national scale for their achievement the purpose is accomplished indirectly through studies by the United States Bureau of Mines of the facts contained in the accident reports the competing companies furnish to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest.The statistics which constitute the basis for determining the winning companies and the relative standing of all companies are prepared uniformly without regard to the States in which the companies operate, or to differences in classes of accidents covered by State laws relating to compensation for injuries resulting, from industrial accidents.Bronze trophies, known as 'Sentinels of Safety', which were provided by The Explosives Engineer magazine to be awarded annually by the Bureau of Mines, were presented to five companies in the contest of 1933, each company having established the best accident-prevention record within one of the five classes into which all companies were divided, namely, anthracite-mining companies, bituminous-coal-mining companies, metal-mining companies, operators of nonmetallic-mineral mines other than coal mines, and quarries or opencut mines. The trophies are awarded for 1 year and are then transferred to the winners of the succeeding year's contest.The trophy for bituincus-coal mines was won by a company in Wyoming. A company in Tennessee won the trophy for metal mining. In the nonmetal-mine group the trophy was again won by a company in New York. A quarry in Michigan won the trophy for the quarry-and-opencut-mine group. The trophy for anthracite mines remains in Pennsylvania, as all anthracite mines in the contest are in that State."

Jul 1, 1934

An experimental study of the soil mechanics of brown coal showed that brown coal consolidates in the same manner as does a clay and that the theory of consolidation for soils may be applied to brown coals. Moisture content is a function of the coal type, the existing effective stress, and the stress history of the coal.The effective stress in a brown coal seam is a function of the overburden pressure, the pore stress and tectonic stresses. Stress history may be deduced from geological evidence and determined by consolidation tests. Application of these principles to the brown coal seams of the Latrobe Valley shows that the distributions of natural moisture contents are consistent with consolidation.INTRODUCTIONThe nature and geology of the brown coals of Victoria, particularly of the Latrobe Valley, were discussed in some detail by Edwards (1945, 1948), Thomas and Baragwanath (1949) and Gloe (1960). A salient feature of these studies was the distribution of moisture contents in the brown coal seams. Recent experimental work, part of a soil mechanics study of the structure and strength of brown coal, showed that moisture content variation is a reflection of consolidation phenomena in brown coal and application of the results to .field condItions verified and modified the conclusions of Edwards in his pioneer work. Further detail of this experimental work is recorded elsewhere (Rosengren, 1961).EFFECTIVE STRESS AND CONSOLIDATIONEffective stresses in soilsA saturated soil is a two-phase system, consisting of a compressible skeleton of rigid soil particles and pores filled with water, an incompressible fluid. (In this context, the terms compressible, incompressible, and rigid are relative only and refer to orders of magnitude). If this system is subjected to stress we define...

Jan 1, 1963

By D. D. Munro

Finsch Mine is a kimberlite diamond mine located at Lime Acres in the Northern Cape Province of South Africa. The mine was founded in 1961 and started surface mining in 1964. Underground production commenced in 1990 using a modified blast-hole open stoping method for the mining of Blocks 1, 2 and 3. Block 4 is currently being mined as a block cave. The process of identifying and optimizing a method to mine the Block 5 orebody started in 1991, and in 2006 incline caving was identified as being technically feasible. This paper aims to document the process employed in developing this method by the Block 5 prefeasibility team as well as discuss the technical challenges encountered during this process. The paper commences with a history of Finsch Mine and highlights the complex geology and threat of sidewall failure that prompted the decision to use block caving as the mining method for Block 4. A literature study of mines that implemented mining methods upon which the incline cave was conceptualized is then presented. These practices were then used to form the basis for the designs on which the initial geotechnical modelling was done and built upon through an iterative process of modelling and design changes. The ventilation of the mining area, initial productivity simulation results, and the applicability of automation and comminution processes in the incline cave are also presented. The paper concludes with an investigation into some of the challenges of the mining method, and shows that that incline caving is a technical option available for further investigation in determining the optimal mining method to be employed at Block 5, Finsch Diamond Mine. Keywords massive mining, incline caving, geotechnical modelling.

Jul 1, 2013