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By J. L. Holman

The Bureau of Mines is conducting research to improve technology for the recovery of strategic and critical metals, such as cobalt, nickel, and chromium, that are lost in bulk and particulate superalloy-type scrap because it has not been possible to process mixed contaminated scrap efficiently. The research approach involves melting and casting mixed superalloy scrap into soluble anodes for electrodeposition of Ni-Co alloys by controlled-potential electrolysis. The initial experimental results described in this report are from electrolytic tests us-ing alloy anodes cast from elemental nickel, cobalt, and chromium, the main constituent metals of superalloys. Baseline data and operating parameters are necessary for Ni-Co and Ni-Co-Cr alloys before detailed experiments can be conducted on the more complex superalloy scrap. This basic research assessed the effects of cathode potential, S04:CI electrolyte ratio, electrolyte pH, stirring rate, deposition time, cathode current density, and chromium concentration on cathode current efficiency, alloy deposit composition, and deposition potential at a cell temperature of 55° C.

Jan 1, 1985

By J. A. Hudson, D. L. Millar

Paper presented at a meeting on: Artificial intelligence in the minerals sector, held in Nottingham, UK, 20 April 1993 (original title: Rock engineering system performance monitoring using neural networks.) Synthetic and analytical approaches to objective-based design of rock engineering projects are discussed. Rock masses are considered as complex dynamic systems with components that concurrently interact with each other and their environment. The existence of a rock engineering system canon (i.e. a set of systems governing rules) is proposed. Its possible components are highlighted and an application is demonstrated using a "rock mass automaton" designed to simulate dynamic heat distribution in rock. In the example given, the canon implements the basic result from probability theory applied to the thermodynamics of solids. Rock engineering system performance is reduced to the mapping of the output of a rockmass to varying input (design) options, within the state space of the systems model. The Kohonen Self-Organising Map provides an extremely useful analytical tool to reduce the hyper-dimensionality of rock engineering system behaviour. Further, the hyper-dimensional state vector is mapped "quasiconformally" such that the neural map tends to spatially organise similar input state vectors, facilitating interpretation of rock engineering system behaviour (performance monitoring). Work is reported on the development and validation of the automation as a basis for an internal representation of the rock mass bahaviour. The results are reported of simulations compensating for the uncertainty of the exact mechanisms operating within the rock mass, using additive noise with the input state vector in the training stages of the self-organising map implementation. Initial work on adopting Grossberg's Adaptive Resonance Theory neural network architecture for classification of rock engineering systems behaviour is also presented

Apr 1, 1994

By J L. Mauk

The Gladstone Hill area hosts epithermal veins similar to those at Martha Hill, which is less than one kilometre away. There are several vein types in the Gladstone Hill area including (1) pyrite-marcasite, (2) quartz, (3) base metal sulfide, and (4) calcite. Pyrite veinlets formed first, whereas the quartz and carbonate veins formed later. The base metal sulfide vein occurs at depth and is predominantly comprised of quartz and chlorite intimately intergrown with pyrite, sphalerite, galena, and rare chalcopyrite. Platy calcite and massive calcite veinlets were the last vein types to form. Several vein textures occur in the Gladstone Hill area, including colloform and crustiform banding, lattice-bladed, zonal, comb, massive and feathery textures. Crustiform banded veins are the dominant texture and contain variable gold-silver grades. Colloform banded veins consist of ubiquitous quartz and minor chalcedony with gold grades as high as 60 g/t. The lattice-bladed texture forms from the deposition of calcite, which has been replaced in many samples by quartz, indicating that boiling and later cooling has taken place. Unreplaced platy calcite only occurs at deeper levels (>300 m). Zonal and comb textures are preserved in quartz and late-stage amethyst veins. Feathery textures within quartz are commonly associated with breccias and some colloform banding, and with significant Au-Ag grades.   The homogenisation temperatures (Th) of primary and secondary inclusions in quartz, amethyst and platy calcite range from 166 to 274¦C, with salinities <1.3 wt% NaCI equiv. The presence of vapor-dominated inclusions and primary fluid inclusions in platy calcite suggests that boiling occurred intermittently throughout deposition. The veins formed under a relatively flat lying paleowater table that occurred 280 - 300 m above sea level. The fluids involved in vein formation were alkali chloride in composition and low in CO2.

Jan 1, 2001

By J. D. Stone

This paper briefly reviews the adequacy of existing management theories and practices and the managerial proficiency or competency in the South African mining industry. The investigation revealed that existing management practices are totally inadequate to enable all employees on all the levels of the mining industry to achieve the results required from them, in all aspects, at all times. As a result, the South African mining industry is gradually losing its long standing reputation as a relative cheap, competitive, and reliable supplier of minerals to the local and global markets. According to some prominent management authors and theorists, an all-inclusive unified management theory does not exist at present. In this paper the authors summarize the main aspects of a newly developed comprehensive, practical, and integrated management method. It is believed that the application of this method would significantly improve the future performance and competitiveness of the South African mining industry

Jan 1, 2010

By G. L. Smith

The fundamental challenge facing mineral and metal companies is how to create sustainable value while operating within mandated strategic bounds, identified constraints, and variable market and economic conditions. This can be achieved by allowing the fixed physical nature of the mineral asset to drive definition of the optimal technical solution to mining and processing activities, and developing and resourcing a strategically aligned portfolio of production entities that creates flexibility to near- and longer-term business environment shifts, i.e. a production mix that allows variation of output to respond to short term market variation, within a long term context. The practical achievement of this outcome is enabled by the concept of strategic long term planning. The core elements of strategic long term planning in the metals and minerals industry, and the relationship between them, are expanded. The strategic long term planning framework is a logic construct that enables delivery of an optimized, strategically-aligned business plan from the mineral asset portfolio using a set of tools and techniques with a common language, standards, systems and processes to align decisions and actions on a cyclical basis.

Jan 1, 2012

By V. Pawlowsky-Glahn, E. Pardo-Igúzquiza, J. J. Egozcue, R. A. Olea

Compositional data constitutes a special class of quantitative measurements involving parts of a whole. The sample space has an algebraic-geometric structure different from that of real-valued data. A subcomposition is a subset of all possible parts. When compositional data values include geographical locations, they are also regionalized variables. In the Earth sciences, geochemical analyses are a common form of regionalized compositional data. Ordinarily, there are measurements only at data locations. Geostatistics has proven to be the standard for spatial estimation of regionalized variables but, in general, the compositional character of the geochemical data has been ignored. This paper presents in detail an application of cokriging for the modelling of compositional data using a method that is consistent with the compositional character of the data. The uncertainty is evaluated by a Monte Carlo procedure. The method is illustrated for the contents of arsenic and iron in groundwaters in Bangladesh, which have the peculiarity of being measured in milligrams per litre, units for which the sum of all parts does not add to a constant. Practical results include maps of estimates of the geochemical elements in the original concentration units, as well as measures of uncertainty, such as the probability that the concentration may exceed a given threshold. Results indicate that probabilities of exceedance in previous studies of the same data are too low.

Jan 1, 2015

By Alastair Grogan

In October of 2002, the author was retained by Public Works and Government Services Canada, on behalf of the Department of National Defense, to design, construct and test the effectiveness of a bubble curtain system at an underwater demolition range, near Victoria, BC. The purpose of the bubble curtain was to reduce the potential for fish mortalities at the site. This paper presents some of the elements of the design, along with the results of overpressure monitoring during blasting and compares the results of fish mortality and animal behaviors with and without the bubble curtain in operation.

Jan 1, 2005

By Jacob Chacko

The Izmit Bay bridge, a 3-km-long suspension bridge crossing of Izmit Bay, Turkey is planned to be constructed in one of the most seismically active places in the world. The site, which has the potential to experience significant earthquakes associated with the relative motion accommodated on the North Anatolian Fault, is underlain by deep deposits of soft soils, and areas of unstable and liquefiable soils. Characterizing the seismotectonic setting, foundation soil conditions, potential fault locations, as well as other geohazards was a critical component for the project concessionaire to finance the project and obtain meaningful bids for bridge design and construction. Given the Build Operate Transfer (BOT) funding mechanism, executing this work in the least possible time was critical to the concessionaire?s financing scheme. Fugro was retained to provide geotechnical, geological, and seismological evaluations for the project region, and to generate data for contractors to develop reliable designs and bids. The uncertainties in these data made it difficult for the BOT concessionaire to finance the project and tender Bridge design and construction. The investment in an early and comprehensive site characterization program to evaluate and quantify those uncertainties allowed the concessionaire to save schedule, provide a robust bid basis to bridge contractors, and persuade banks to finance what was perceived to be a relatively high risk project.

Jan 1, 2011

By D. F. Malan

This study reviews the concept of squeezing (large time-dependent deformation) in rock and investigates the possibility of this phenomenon becoming more pronounced in the planned ultra-deep mines of the South African gold mining industry. Although squeezing behaviour is not commonly found at the current depths of the gold mining industry, it is observed at Hartebeestfontein Mine due to a combination of weak rock and high stresses. Calculations based on the average strength of the Witwatersrand quartzites and the competency factor used to identify squeezing conditions in civil engineering tunnels, indicate that there is an increased risk of squeezing behaviour in ultra-deep mines. This will adversely affect the profitability of these mines and highlights the need for further research into the time-dependent behaviour of rock. Finally, the current support strategies in squeezing conditions are reviewed.

Jan 1, 1998

By Raymond W. Hiteshue

Experiments were conducted al temperatures of 480° to 800° C. and hydrogen pressure of 6,000 p.s.i.g. to determine the effect of coal residence time on the conversion of a high-volatile bituminous C coal to liquid and gaseous products when using a semicontinuous apparatus designed fur rapid heating and cooling of reactants. The objective of the studies at high temperatures was to determine if appreciable quantities of coal could be converted to gaseous hydrocarbons and low-boiling liquid hydrocarbons. Experiments at lower temperatures were designed to indicate shifts in product distribution with respect to temperature and to learn more about the general mechanism of the reaction when using close control of coal residence time. One percent molybdenum, based on m.a.f. (moisture-and ash-free) coal, was used throughout this investigation. At 800° C., 6,000 p.s.i.g., and "zero" residence time) the yield of gaseous hydrocarbons was about 38 percent and the yield of oil about 4.5 percent, based on m.a.f. coal. With IS minutes residence time, under the same conditions, the yield of gaseous hydrocarbons was approximately 80 percent with no increase in yield of oil. Apparently at 800° C., and hydrogen pressure of 6,000 p.s.i.g. coal was rapidly carbonized to char with expulsion of volatiles. Char was then slowly hydrogenated to gaseous hydrocarbons without production of oil.

Jan 1, 1962

By Marc C. Bétournay

Over the last four years, an international initiative, championed by Vehicle Projects LLC, the Fuelcell Propulsion Institute and Natural Resources Canada, has been active in carrying out research projects to prove out the concept of applying fuelcell technology to underground mining vehicles. These have been carried out by a consortium consisting of mining companies, equipment manufacturers, technology developers, national laboratories and consultants, with the participation of Canadian and U.S. mine regulatory agencies. This clean technology, which produces only water and electricity, would allow several advantages to be obtained, in the health area (by eliminating diesel emissions and reducing noise generation), in lowering production costs (such as reducing ventilation required) and lowering green house gas emissions. This article outlines the results obtained in several key areas, such as the operation of fuelcells in underground conditions, risk issues related to underground and surface operation of hydrogen vehicles and hydrogen production and delivery systems, and the design and mining performance of the world?s first hydrogen mining vehicle, a mine production locomotive. The work to date on the fuelcell loader, designing the power plant and power transmission systems, operational requirements, and operating cost reductions, is also presented. There is also an evaluation of the overall mining applications and advantages this technology can bring to underground mining, including the facilitation of automation and tele-remote operation.

May 1, 2003

Editor’s note: As usual, the June issue features an industrial minerals review. And some thanks are in order. Thank you to the industrial minerals annual-review editor, to the technical committees chair and vice chairs and to the authors of the individual commodity profiles. Jim Norman of GeoTrans Inc. is the industrial minerals annual-review editor. William Langer, U.S. Geological Survey, is the chair of the SME industrial minerals technical committees and the vice chair of the technical committee for construction materials. Other technical committee vice chairs include: •Lucy McCartan, U.S. Geological Survey, agricultural minerals. •Steve Herron, Oglebay Norton Performance Minerals, ceramics and refractory materials. •Srinivas Veeramasuneni, U.S. Gypsum, chemical raw materials. •Ismail Yildirim, Imerys, fillers and pigments. •Charles Landis, BPM Minerals, sorbents, filters and process aids. •Ray Harris, Wyoming Geological Survey, specialty minerals. Their help makes possible this June industrial minerals issue. On behalf of the readers, the editors thank them

Jan 1, 2004

By V. L. Franzen, Z. J. Hladysz, C. A. Kliche

The Wharf Resources mine, located in the Bald Mountain Mining District approximately 6.4 km (4miles) west of Lead, South Dakota, has operated a surface gold and silver mine and heap leaching processing facility since 1983. Wharf Resources intends to mine and process gold and silver ore from the Wharf Expansion area which is located on the eastern flank of the currently permitted Foley Ridge Mine. The Trojan Pit for the Wharf Expansion area was initially designed with an overall highwall slope angle of 45o. During mine permit presubmission meetings with personnel from the SD Department of Environment and Natural Resources (SD DENR), the question arose as to whether a detailed slope stability analysis of the proposed Trojan Pit highwalls was completed to justify the 45o slope. Wharf’s response was that the highwall design was based, in part, upon studies completed in1987 on the Annie Creek and Foley Ridge Mines; and, in part, upon subsequent slope stability analyses conducted by Wharf mine personnel through 1996. It was suggested by the SD DENR that the stability study be updated to reflect structural geological conditions in the Wharf Expansion area.

Jan 1, 2000

By Joseph L. Margin

From a stubborn start to record setting performances in little over a year, that is the story of the English Running Tunnel Boring Machines. The program to transfer technical information on these highly advanced machines from builder to user will be discussed as a vital link to this accomplishment. Some interesting features of these machines will be covered as well as a recounting of the various conditions that were encountered during these drives and how they were resolved.

Jan 1, 1991

Titanium and Zirconium Industries Pty. Ltd. separates rutile and zircon from heavy mineral concentrate recovered from sand dunes on the east coast of North Stradbroke Island, Queensland. Separation plant feed is delivered to Dunwich, on the west coast, by a seven mile aerial ropeway traversing the island. Mining and concentration is effected by two floating dredge-concentrators now operating on the beach 31; miles from the aerial ropeway terminal. Heavy mineral concentrate is transported hydraulically from the dredges to the ropeway through a 6 in. pipeline. Six pumps in series deliver 24 ton/hr of dry solids in a pulp containing 13 per cent solids. For maximum economy the transfer pumping system is controlled deliberately to cause transportation in the zone of incipient settlement of solids, ieat velocities below the limit deposit velocity for the particular pipe diameter, pulp density, and specific gravity of solids. Automatic density control, based on a combination of power consumption and pipeline pressure, eliminates the danger of plugging the line but periodic flushing is necessary to remove gradual accumulation of solids in the bottom of the pipe. After 15 months operation the pipeline was descaled with hydrochloric acid to remove severe blistering with rust nodules, regrowth of which is now prevented by continuous injection of inhibitors. After transporting 100,000 tons of heavy mineral the average wear on the steel portion of the pipeline was 0·01 in. and indications are that wear on the asbestos cement portion is less.DESCRIPTION OF OPERATIONSGeographyTitanium & Zirconium Industries Pty. Ltd. (T.A.Z.I.) operates on North Stradbroke Island, some 30 miles southeast of Brisbane, Queensland. The island is approximately 25 miles long and eight miles wide, and is bounded on the east by the Pacific Ocean and on the west by Moreton Bay (Fig. 1). With the exception of a small outcrop of volcanic 1. Manuscript received at The Institute. 8th May. 1962. This paper was presented at the Annual Conference of The Institute. 5th-11th August. 1962.

Jan 1, 1962

By David R. Morrey

During the past 50 years, significant research has been performed in the ecology and physiology of plants that colonize soils containing elevated concentrations of heavy metals. Similar work has also been performed on plants that are able to survive acidic and saline environments. Efforts have focused on the ecological analysis of plant communities that occur over a range of metalliferous mining wastes. Investigations have been performed on the mechanisms that allow selected varieties of plant species to survive in normally phytotoxic environments and on the potential applications of metal-tolerant varieties of plant species. The purpose is the remediation and reclamation of mining wastes and soils that contain unusually high concentrations of so-called heavy metals. Characteristics of some mineral wastes Metalliferous mining wastes present special environmental restoration problems because of their toxicity. Potential toxicities are mostly caused by residual metals derived from weathering of low-grade ore or the waste products of mineral processing. In cases where pyrite forms a part of the mining waste, acid generation by oxidation may exacerbate the toxicity problem by promoting heavy-metal mobilization in aqueous solution.

Jan 1, 1995

By Tim Edwards, Richard Triglavcanin, Ian Arbuthnot, Darren Colwell, Brad Garraway, Ken Roberts

"In the mineral processing industries, there is an increasing need to design thickeners which are able to produce high density underflows usually referred to as “paste”.The behaviour of a flocculated suspension in compression needs to be well understood in order to arrive at a reliable thickener tank configuration (i.e. diameter, cone angle and depth) for a required paste result.As a suspension approaches paste consistency, it’s fluid characteristics change markedly. It develops a high yield stress, and may have an increased tendency to form agglomerates, which lead to a phenomenon known as “rotating beds”, “donuts”, or “islands”. These characteristics present challenges to the designer of the rake mechanism.The subject paper addresses the requirements for designing a paste thickener, covering the following topics:o Testwork for thickener sizingo Design of rake mechanismso Suspension rheology and effect on designo Case studiesTESTWORK AND SIZING FOR PASTE THICKENERSThickening slurries to the maximum possible density (paste) is becoming increasingly common. Applications such as Autoclave feed thickeners, paste backfill and some counter current washing (CCD) circuits are all examples of potential paste thickening applications. The principle of paste thickeners is that the compression zone is much deeper than on either high rate (HRT) or high compression (HCT) units; generally 3 metres or more. As the compression zone gets deeper, theunderflow density for a given flux rate (tph/m2) increases, as a result of two factors:1. Longer bed settling time. Settling flocs move relative to one another and release interstitial fluid when they are in compression. Increasing bed residence time achieves higher density underflow as more fluid is removed.2. The nett weight of the bed creates a compressive force on the settling flocs. This force increases with depth, so that the flocs at the bottom of the bed experience the highest compressive force. This represents the driving force to expel interstitial fluid and hence increase bed density."

Jan 1, 2005

By F. D. Ford, Z. Dai, A. Byers

Manitoba Mining and Milling operations consist of three underground mines (Thompson T1, T3 and Birchtree), feeding the Thompson Mill. Three years ago, a collaborative effort involving Mines Exploration, Mines Project Development Group, Mill Technical Services and Vale Base Metals Technical Excellence Center was initiated to establish and verify the cause of high variability in concentrate quality and Ni recovery at the Thompson Mill. One outcome of this work was a program to systematically characterize the mineralogy and metallurgical performance of current and future orebodies feeding the mill. Mineralogy results show that high value enabling ores typically have a high pentlandite to pyrrhotite ratio and benign silicate mineralogy (mostly quartz and feldspar from sedimentary host rocks), while metallurgically challenging ores contain some combination of pyrite and/or hexagonal (non-magnetic) pyrrhotite and/or elevated quantities of talc (with associated carbonates) derived from altered ultramafic host rocks. The metallurgical performance of these two ore types has been simulated by an Excel particle flotation model, which calculates the relative floatability of particles based on the particle’s mineral composition and mineral locking determined from MLA images. The relationship between these mineral properties measured by MLA and metallurgical performance was established using 13 monthly composite samples from Thompson Mill. The model was then validated with results of laboratory flotation experiments on individual orebodies submitted for evaluation. The validated model can be used to predict plant metallurgical performance based on individual ore bodies feeding the mill. Individual orebody’s grade-recovery curves are assumed to be additive, and can be weighted in proportion to the mill feed to predict mill recovery over the same time period. The ore mixing can be done with a simple Excel spreadsheet and comes with a graphical output for easy visualization of the resulting grade-recovery curve.

Jan 1, 2015

By Hassell E. Hunter

The Wyoming Mineral-Conoco Crownpoint Project represents the first time that big hole drilling has been exclusively used to develop totally a privately financed mine below a depth of 1000 feet. Three shafts, one ten feet in diameter and two six feet in diameter, were successfully drilled to depths of 2243', 2188' and 2188' respectively and cased with hydrostatic designed steel casing. The largest shaft is to be used to handle muck and water from station excavation and enlargement of the other two shafts. A reverse circulation system with potassium chloride base mud was used for drilling. The mud was cleaned by settling in steel lined tanks with assistance by cyclone type separators. Deviation was monitored by gyroscopic surveying at 30 foot intervals and did not exceed 16 inches off plumb. Casing was designed to withstand hydrostatic pressures with a 1.5 safety factor to the large shaft and 1.25 safety factor for the smaller shafts. All casing welds were x-ray tested prior to lowering the casing in the hole. Cementing the annular space completed the operation. The total time to mobilize, drill and move off the three shafts was 363 days. The drilling operation was completed ahead of schedule and under budget.

Jan 1, 1983

By Tom A. Armour

Different variations of soil nailing techniques have been used in the United States since the late 1970's. Such techniques owe their origins to French developments, which began in the early 1970's as a spin-off from European tunneling excavation support practice. The growing demands of urban infrastructure development and rehabilitation and environmental protection have created an active and expanding soil nailing market demand for earth retention and slope stabilization in the United States since its early developmental years. There is a clear need for a fundamental review of the large number of soil nailing techniques that are currently being used in the United States. Following a brief summary tracing the historical development of soil nailing and a generic classification of applications, this paper provides a review of the different recent advances in the design and construction of soil nailed systems. Discussion topics include nail design advances, permanent "top-down", structure support/underpinning, alternative face stability measures, composite systems, hollow bar and fiberglass nails and architectural reinforced concrete/shotcrete facings. Case histories will be presented to illustrate each of these advances.

Jan 1, 2003