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By Stanley Griff, William Herrera, William O. Seals

"The Navy initiated liquid propellant research in the early 1940's. The first promising Navy liquid propellant, Otto Fuel II, was developd in the early 1950 as a potential torpedo fuel. Later, the Navy developed a HAN based liquid propellant designated NOS-365, a hydroxylammonium nitrate, isopropylammonium nitrate and water formulation. A large gas volume generated by this propellant produced a large wake behind the torpedo. As one can readily understand, this negated the useof the propellant for this application. Recognizing the large gas volume as a desirable propulsion system for guns, the Navy embarked upon a gun propellant proqam. Utilizing a bulk loaded gun sysytem, the program failed when the gun was destroyed by the propellant detonating."

Jan 1, 1990

By J. W. Thompson

A contract stipUlating for the delivery of quantities of phosphate rock" f. o. b. mines," and stipUlating that" while this contract is in form an absolute sale for a fixed quantity in each year, it is mutually understood and agreed that the purchase is for the buyer's consumption and not for a sale; the buyer agreeing to give to seller the refusal of any surplus over and above the actual consumption. Buyer is at liberty to increase or diminish the quantity called for in any year, to the extent of not exceeding 10 per cent; provided that the quantity to be taken shall not be less than buyer's consumption; provided further that notice of such increased or diminished demand be given seller 12 months in advance of such change," is to be construed as a contract for the sale of stated quantities of rock, deliverable in approximately equal quantities during each year for the specified series of years, subject only to be increased or diminished after specified notice in any year, where the amount taken would not be les<; than the buyer's consumption, not exceeding 10 per cent, and the contract indicating that the rock was intended by both parties for consumption in the fertilizer plant of the buyer. but the quantity to be taken was not limited by the necessities of' the plant.

Jan 1, 1916

By AIME

Burton J. Westman-Besides decreasing the diamond size, there appear to be two other approaches open to overcome excessive diamond loss and, more particularly, the rapid diamond polish that took place in this quartz-feldspar rock. First, however, a short discussion of the diamond characteristics should be made in order to discuss the situation more clearly. The West African diamonds which we can assume were used. for this drilling have two disadvantages when drilling hard, exceptionally fine-grained rocks. These are rapid polishing and, if .the bit isn&apos;t "drilled in" carefully, a tendency to damage, resulting in excessive diamond loss. The normal wear resistance of any diamond is inversely proportional to the compressive strength of the diamond, therefore only the highest grade, of diamonds free from insipient fractures should be employed. Using upwards of 90 diamonds per carat instead of the20 to 30 per carat not only decreases the total projected area of the cutting points but increases the stress per point which, in turn, causes greater depth of penetration into the rock. Considering this depth of penetration, therefore, suggests an approach other than increasing the, number of diamonds per carat and that is to decrease the actual number of diamond points (also the carat weight per bit) so that the penetrating force on an individual diamond is increased. This penetration increases the chipping or rock shearing action.

Jan 1, 1950

By Eduardo Lozano, Vilem Petr

This paper provides an overview of a new method for avalanche control using a high explosive charge placed at the avalanche runout zone: the case charge technique. This new avalanche control technique is well-suited to mountain roads presenting several advantages over the existing methods: minimum deployment time, low cost, reduced probability of misfires, and decreased operation time in the avalanche danger zone. The research work presented in this paper was conducted via large scale laboratory experiments where the detonation velocity and the blast physical properties were measured. During the charge design, several parameters were controlled: charge mass, diameter, geometry, density, and external confinement. In addition, the effective range of case charges was increased by the use of the Mach reflection for certain topographical situations. Finally, field test results collected by the Colorado Department of Transportation (CDOT) during the 2017 winter season are presented. The CDOT avalanche control crews have adopted the new case charge as the preferred technique in numerous avalanche locations along the Rocky Mountains roads.

Jan 1, 2018

Operator efficiency and control capability along with cost effectiveness have been the quest of mining, industrial, and mobile hydraulic engineers for years. The majority of the functions in present day fluid power systems are controlled by on/off control valves. They are inexpensive and provide easy installation and operation, but they lack the quality of fine control of load flow or what is sometimes known as "feathering the load". An alternate approach to obtaining this capability is the use of electro-hydraulic servo-valves, but their implementation into a system is complex, and they are expensive. As a result, electrohydraulic systems are still used primarily in the aerospace industry. Of late, a compromise seems to have evolved between the on/ off control systems and the servo-technology is the so-called proportional flow control valves. A proportional flow control valve meters fluid to the load in proportion to the input command from the operator. In principle, it is similar to a conventional flow control valve and is tailored to meet the control requirements from the load point of view. The hydraulic system using this valve usually works in an open-loop mode with the operator closing the loop. Incorporating load-sensing mechanisms and adoption of electrical/electronic signalling into the valve make it the "ideal valve" which designers have been looking for from a techno-economic point of view.

Jan 1, 1983

The lead concentration of flotation feed ore slurries is determined using two ?-ray absorption gauges mounted directly on a 6 in. diameter flotation feed pipeline. One gauge is a conventional &quot;density&quot; gauge using CS137. The other is a &quot;lead-sensitive&quot; gauge, which depends on the preferential absorption. by lead of 225 key y-rays resulting from Compton backscatter of CS137 y-rays.Gauge outputs are combined using an analogue computer the output signal of which is directly proportional to the lead concentration of the pulp. The accuracy of measurement of the pulp lead concentration is &#177; 3&#183;6 per cent for ore slurries with lead concentrations in the range 0&apos;07-0&#183;16 g/c.c. and pulp densities 1.43-1.60 g/c.c.This paper sets out the development of the technique and details are given of the two experiments (1964, 1966) conducted in the plant at North Broken Hill Limited. The installation of the two-gauge system inthe plant during May 1968 is described. Details are given of the calibration technique used and the results obtained.

Jan 1, 1969

By S Thacker, M Noakes

The Newmont Tanami Operations (NTO), formerly the Granites Gold Mine, commenced operation in the mid-1980s with tailings deposition evolving over the past three decades as production has increased and the operation has expanded. Paddock-style tailings storage facilities (TSFs) and in-pit tailings deposition have fulfilled the tailings requirements for NTO over its lifetime with the technical specifications of these facilities improving over time in line with the positive development of standards, guidelines and best practice.This paper reviews the options for tailings storage facilities at NTO and the many considerations that have been analysed and deliberated upon before settling on specific TSF types and designs. It also explains the operating philosophies of the tailings deposition and how the facilities have always strongly maintained the optimum capture and retrieval of water. The current TSF design and criteria is presented, along with the introduction of dry tails harvesting for use in paste production as a backfill product for the underground mine. Tailings deposition and recovery remains a critical function of the Granites process to ensure long-term operation and gold production.CITATION:Thacker, S and Noakes, M, 2015. Newmont Tanami Operations – tailings storage facilities, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 305–314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By W. K. Connor, O&apos

The U.S. Bureau of Mines, in cooperation with the Idaho National Engineering Laboratory (INEL), conducted over 30 hours of melting tests to vitrify simulated low-level radioactive wastes from the INEL Radioactive Waste Management Complex (RWMC). Five separate waste compositions were investigated, each consisting of noncontarninated soil from the RWMC and surrogate materials used to simulate the actual buried wastes. The RWMC soil and five waste compositions were melted in a 50-lb, single-phase electric arc furnace with a water-cooled shell. These tests were conducted to determine melting parameters in preparation for a large-scale melting campaign to be conducted in the Bureau&apos;s 1-metric ton (mt), water-cooled-wall, 3-phase electric arc fumace. Bulk chemical composition was determined for each of the feed materials and for the slag, metal, fume solids, and offgas furnace products, and distributions were calculated for the key elements. The material balance for the furnace operation indicates that from 63 to 84 pct of the feed reported to the slag. Cerium, used as the surrogate for the radionuclides in the wastes, demonstrated an extremely strong affinity for the slag product. Although slag temperatures as low as 1250° C were recorded when melting the RWMC soil, temperatures in excess of 1600° C were necessary to achieve the fluidity required for a successful slag tap.

Jan 1, 1994

By David E. Kaslow

In sampling dust laden air by drawing the medium into an inlet, some larger particles fail to follow the air and a true sample is not obtained. Inertia prevents particles from accelerating with the air as well as from turning sharp bends; also the particles&apos; weight causes them to fall relative to the air. An analytic solution to the sampling efficiency calculation by Levin gives particle paths and sampling efficiencies for various particle sizes when the inlet can be treated as a point sink. However, the flow field in the neighborhood of an aspirating tube is quite different from a point sink flow. Employing Levin&apos;s solution in the outer field, trajectories in actual flow fields have been calculated by computer to locate the critical trajectories separating the entering particles I paths from those paths where the particles hit the tube wall or escape. Sampling efficiencies are presented in terms of 3 variables--a dimensionless particle size coefficient, a dimensionless orifice size coefficient and the tube orientation--for the no-wind case. Over most of the range of sampling conditions, the Stokes drag law can be used and dependence on the variable--particle Reynolds number--can be ignored. A procedure for achieving maximum efficiency in design of a sampler is proposed. Whether these results apply when typical room-sized eddies constitute the ?calm air? environment is not known.

Jan 1, 1974

By S. Narra

The importance of bio-products production is enhanced with the abundance and renewability of ligno- cellulosic biomass in comparison to the depleting fossil fuels especially in producing environment friendly energy. Lignin is obtained as a sludge residue from the pulp and paper industries as well as from the bio- ethanol /bio-gas production plants. Lignin is a renewable fuel with a high heating value equivalent to anthracite coal, low ash content and hydrophobic properties. The extracted lignin in paper and pulp mills is usually burnt at the mill directly to cover the energy production costs of the mill. The efficient utilization of lignin can reduce the percentage of lignin sludge used for energy production in comparison to the present situation. Presently the lignin is burnt /incinerated as sludge with minimum of 30 to 50 % moisture content. This high moisture content reduces the energy efficiency and simultaneously utilizes more amount of lignin sludge in producing the required energy. This paper explains a possibility of integrating sludge-pelleting techniques in paper and pulp mills. The integrated sludge-pelleting techniques would lead to an optimal utilization of lignin for energy and would simultaneously save the lignin resource for material utilization. The sludge pelleting process solves also the problem of handling, storage and explosion risks of lignin when compared to the present situation.

Sep 1, 2012

By R. L. Stein

For the past several years, the Bureau of Mines has been actively engaged in developing two new oxygen self-rescuers through research contracts with private industry. These new oxygen self-rescuers are designed to be carried by a miner while he is at work and are used during emergency escape, supplying high-purity oxygen to the user and, at the same time, absorbing carbon dioxide (C02), The first of the two new self-rescue breathing devices is a 10-minute, self-contained apparatus developed by the Mine Safety Appliance Co, Size and weight of the unit are comparable to the currently used self-rescue devices. The second device, designed and developed by Lockheed Missiles and Space Corp., is 8. 4.5-lb package which supplies 1 hour of oxygen to the miner. Both devices have a canister which contains the oxygen-producing and CO2-absorbing potassium superoxide chemical, a breathing bag, a bite-type mouthpiece, noseclip, goggles, and hoses connecting the canister and mouthpiece. When needed in an emergency, the miner removes the outer protective cover and dons the unit. For both devices oxygen is immediately available once the mouthpiece is placed in the mouth. These two new units have received prototype approval from the National Institute for Occupation and Safety Health (NIOSH) and the Mining Enforcement and Safety Administration (MESA).

Jan 1, 1976

By D Kent, J Bullock, M Wilkinson

Over the last few years at Glencore’s Mount Isa Copper Operations (MICO) mining conditions have become increasingly challenging through lower head grades and higher work indices. MICO has had great success improving operating efficiencies and increasing productivity through focusing on technology, innovation and operational discipline. The recent implementation of the Mine Site Technologies (MST) ImPact System has supported the continued transformation of the MICO operations through improved personnel safety and direct measurement of productivity. The ImPact System has implemented new safety systems such as the heavy vehicle proximity detection system, underground personnel tracking system and emergency evacuation dashboards improving the overall safety of the workforce. The ImPact System has facilitated productivity improvements via real-time equipment and personnel monitoring, and the implementation of exception reporting (personnel productivity), KPI reports and production dashboards, and transparent reports highlighting developing maintenance issues.This paper discusses the components of the ImPact System, the current installation at MICO, and critically analyses the implementation processes and right sizing of the system to meet the needs of the business today and into the future.CITATION:Bullock, J, Kent, D and Wilkinson, M, 2017. Productivity and safety improvements supported by MST’s ImPact System at Glencore’s Mount Isa Copper Operations, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 279–286 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By Ajit K. Sinha

"Abstract - Electromagnetic surveys were conducted over the Yava sandstone-hosted lead deposit in Nova Scotia to evaluate the usefulness of such surveys for detecting and mapping sedimentary­ hosted metallic ore deposits. Both transient and multifrequency systems were used for that purpose. The deposit consists of three zones of disseminated galena which also contain minor amounts of pyrite and sphalerite filling the interstices of the sandstone grains. Each zone overlies a basement depression and is separated from the adjacent zone by an intervening basement high. A conductive shale layer underlies the galena-rich sandstone formation at all three zones.Because the concentration of galena (3% to 4% ) and other sulfides is too low to affect the resistivity of the sandstone formations for detection by ground electromagnetic (EM) methods, the strategy for our survey was to look for areas of basement depressions and the presence of conductive shale in those depressions by EM depth soundings. The presence of the galena-rich sandstone formations could be inferred because of the close association of these two features with the deposits in the Yava area. Both transient and multifrequency EM systems were successful in mapping the basement depressions and detecting conductive shale at the three known mineralized zones. The technique, therefore, seems to offer good prospects for mapping similar stratabound sedimentary-hosted sulfide deposits."

Jan 1, 1993

By W Patton

Investment decisions in the mineral resources sector are made on the basis of an assessment of the economic potential for a mineral deposit. Given the supporting information for the location, scale, and quantity of the commodity of interest, miners and investors aim to make risk-informed decisions when considering further investment. The objective of resource classification is the synthesis of various types and quantities of geologic information used in resource model construction to assign confidence categories to the estimated mineral resources, which can then be used to support informed economic decisions. In this paper a risk-based classification scheme for iron ore mineral resources using conditional simulations is presented. The method involves categorisation of each block according to a confidence level, considering expected recoveries from a kriging model over mining production volumes. The realisations of the simulated model are used to assign risk-based confidence categories to zones of the ore deposit. One motivation for this work is to assess the sensitivity of the scheme to geologic uncertainties. Specifically, that which uncertainty in the layout of mineralising alterations and weathering overprints influence variabilities of associated rock properties and the likelihood of obtaining expected ore recoveries. It is shown these risks have material implications for a project’s economic potential. How the scheme can be extended to the grade control context and the value subsequent grade control activities is also quantified.

May 24, 2023

By T. Damyanov

Spherical grinding media (balls) are the most widely used media for comminution of ores by grinding. A modelling simulation study of the behavior of two grinding media in the grinding process was conducted to determine the possible advantages of the new shape milling bodies called tetraballpebs. Tetraballpebs are in the shape of tetrahedrons with spherical convex walls. A three dimensional CAD model of the mill drum with a diameter of 1200 mm was used. A continuous operating mode was simulated in terms of the 3D contact elements of the model (milling bodies and mill drum). Simulation tests were carried out in a typical grinding mode and at a typical rotational speed of the drum mill (75 per cent of the critical speed in cataracting mode). Studies carried out with both grinding media include equal number of milling bodies with the same weight and volume. Having thus ensured a uniform mass of the grinding media and same number of milling bodies, and constant other conditions and process parameters, conclusions can be drawn about the influence of the shape of the milling bodies on the grinding process. A kinematic analysis of the system using CAE (computer-aided engineering) model parameterization was conducted. The controlled parameters are: ? Power draw; ? Kinetic energy of each milling body; ? Motion of milling bodies inside the drum Keywords: grinding, grinding simulation, balls, tetraballpebs, DEM, CAD-CAE

Sep 1, 2012

By T. S. Smith

INTRODUCTION IN PREPARING this paper for the District 4 Meeting, three factors had to be considered. First, the paper must fit the time alloted; second, it must give a general picture of the geology for those unfamiliar with the property; and third, it must contain some new material in order to be of interest to local delegates. The most comprehensive extant discussion of the geology of the property of McKenzie Red Lake Gold Mines, Limited, is contained in Horwood&apos;s report on the general Red Lake area ( 1). This report is the &apos;bible&apos; of the area, and a general paper on the geology of this particular mine would almost certainly appear to be a condensation of it. It was thought, therefore, that the most suitable procedure would be to base the general outline on Horwood&apos; s report, to extend that outline where possible from information gained since its publication, and finally to leave dangling for the contemplative geologist some of the ideas and problems which ?are currently under consideration. LOCATION AND HISTORY The property of McKenzie Red Lake Gold Mines, Limited, is in Dome township, in the Red Lake mining division of northwestern Ontario. The mine is on McKenzie Island, about four miles north, by water, of the Hasaga mine and old Howey mine.

Jan 1, 1951

By E. Lee Cameron

Summary Records of the past show that the first mineral production in what is now the Province of Manitoba consisted of salt, obtained about the year 1800 by the evaporation of brine. Also at an early time in our history, the Ordovician limestone at St. Andrews Locks, East Selkirk, and other localities was quarried for use as building scone in the construction of forts and fur trading posts. Both salt and building stone are still produced in Manitoba, although not from the original sources. In addition, there is now a substantial production of a variety of other industrial minerals and their products such as lime, crushed stone, gypsum, peat moss, and bentonite. The annual dollar value of production of the industrial mineral industry in Manitoba is today greater than at any time in our past and is derived from a greater variety of products. At the present time, exclusive of the various gravel pits operated by the Provincial Department of Public Works, twenty companies operating thirty-four separate pits, quarries, or mines are producing industrial mineral raw materials in Manitoba. This paper attempts to outline the development of the industry from its start about 1800 to the present, giving general information on the various materials produced. Some suggestions regarding the possibilities of establishing new industries based on other raw materials are given at the end of the paper.

Jan 1, 1949

By Meng Li, Hao Nie, Weitian Ding, Mamdouh Omran, Ying Li, Yao Ge, Yaowei Yu, Abourehab Hammam, Lei Zan

This study examines the isothermal and non-isothermal reduction behaviors of iron ore compacts in a pure hydrogen atmosphere and compares the results obtained during the reduction process by CO. The different phases accompanying the reduction reactions were identified using X-ray diffraction (XRD) and its morphology was microscopically examined. In isothermal experiments, temperature plays a significant role in the reduction process. At any given temperature, the reduction rate during the initial stages is higher than that during the final stages. The reduction rate in H2 atmosphere was faster than in CO gas. The comparison of activation energy values suggested that reduction with H2 is more efficient thanwith CO. At the same temperature, the time required to achieve a certain degree of reduction was lower when using H2 gas than CO atmosphere. In non-isothermal tests, the heating rate has a significant effect on the reduction rate and reduction extent. At the same heating rate, the degree of reduction was higher in H2 atmosphere than in CO gas. Based on experimental data, the parameters of reaction kinetics were deduced by application of model-free and model-fitting methods. The reduction in H2 atmosphere was controlled by nucleation model (Avrami-Erofeev model), while the CO reduction reaction was controlled by gas diffusion.

Sep 29, 2020

By W. A. Parks

Stone that may be applied to purposes of construction is available in nearly all the inhabited parts of Canada, the most important exception being the prairie region, but, even here, the deficiency is overcome in many parts by a wealth of glacial field-stones. In many parts of the country, also, the accessible stone is of a quality so poor that brick is more generally used. There is a great difference, however, between stone that &apos;may be used&apos; and stone suitable for buildings of a monumental type or even for &apos;trimmings&apos; on the better class of dwelling in the cities and towns. It is in the latter sense that the expression &apos;building stone&apos; is commonly used. Thus restricted the term includes varieties of sandstone, limestone, and granite, using the latter word in the custom of the quarryman, not only for the true granite of the geologist but for many other igneous rocks as well. Building stone of high quality grades imperceptibly into stone suitable for monuments, particularly in the case of the granites. The present review will deal with building and monumental stone in this restricted sense and will omit marble, although that material has been used to some extent for building. For instance, the Great West block in Winnipeg is built of marble from British Columbia.

Jan 1, 1925

By L. Zhou, A. Martikainen, G. Goodman

Continuous airflow monitoring can improve the safety of the underground work force by ensuring the uninterrupted and controlled distribution of mine ventilation to all working areas. Air velocity measurements vary significantly and can change rapidly depending on the exact measurement location and, in particular, due to the presence of obstructions in the air stream. Air velocity must be measured at locations away from obstructions to avoid the vortices and eddies that can produce inaccurate readings. Further, an uninterrupted measurement path cannot always be guaranteed when using continuous airflow monitors due to the presence of nearby equipment, personnel, roof falls and rib rolls. Effective use of these devices requires selection of a minimum distance from an obstacle, such that an air velocity measurement can be made but not affected by the presence of that obstacle. This paper investigates the impacts of an obstruction on the behavior of downstream airflow using a numerical CFD model calibrated with experimental test results from underground testing. Factors including entry size, obstruction size and the inlet or incident velocity are examined for their effects on the distributions of airflow around an obstruction. A relationship is developed between the minimum measurement distance and the hydraulic diameters of the entry and the obstruction. A final analysis considers the impacts of continuous monitor location on the accuracy of velocity measurements and on the application of minimum measurement distance guidelines.

Jan 1, 2012