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By D. Paul Bishop, Kevin P. Plucknett, Hung-wei Liu

"Spark plasma sintering (SPS) process has been evaluated for producing the commercially pure (CP) Ti, TiAl and a TiAl-B4C composite. Comparisons were made between the materials in terms of the sintered density, resultant hardness and microstructures. In the present work, the titanium aluminide powders (Ti-48Al, producing a mixture of y-TiAl/a2-Ti3Al) were synthesised „in-house? using a simple reaction-sintering and mechanical attrition approach. This allowed various size distributions to be generated. The powders were then blended with a fine boron carbide (B4C) powder (up to 6 wt.%), and the resulting mixtures were consolidated using spark plasma sintering (SPS) under vacuum in graphite dies. An applied stress of 50 MPa was used for all SPS runs. The SPS parameters were varied in terms of the ultimate sintering temperature (up to 1300°C) and hold time (up to 10 minutes) for each material. It is demonstrated that high densities can be achieved this approach (exceeding 95% of theoretical, with optimised samples close to full density). Microstructural characterisation was conducted using optical microscopy, scanning electron microscopy, and X-ray diffraction. The B4C additions were seen to partially react with the TiAl to form reinforcements, such as TiCx and TiBx. Preliminary mechanical property assessment will also be briefly discussed.INTRODUCTION Titanium- and titanium aluminide-based alloys possess many unique properties, such as excellent corrosion resistance and high temperature strength, respectively (Cardarelli, 2001; Leyens & Peters, 2003). Compared to many other competing materials (e.g. stainless steel or Ni-based alloys), Ti- and TiAl-based alloys also have relatively low densities (~4.5 and ~3.9-4.1 g/cm3, respectively), which is critical for performance in aviation and automobile applications. However, the manufacturing cost is high, due to the expensive raw Ti material and difficulties in machining. TiAl-based alloys are particularly difficult to produce because of their limited ductility (Lütjering & Williams, 2007). To overcome those problems, powder metallurgy (PM) technologies have shown great potential as near-net shape processes for Ti- and TiAl-based alloys. The general PM process largely avoids laborious post-machining and minimises material use. In industrial production, the PM approach has been successfully utilised to manufacture aluminium- and iron-based alloys (Huo & Heath, 2008)."

Jan 1, 2017

By Stuart M. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Aug 1, 2010

By F. Mohamm

"Recent changes in regulations and scientific advances concerning selenium bioaccumulation have placed greater importance on non-biological treatment systems for selenium control. Mining wastewater contains hexavalent selenium (selenate) as the predominant aqueous species and possibly small amounts of tetravalent selenium (selenite). Non-biological removal of selenite is accomplished readily and cost effectively by ferric co-precipitation and adsorption using ferric oxyhydroxides sourced from ferric salts or iron anodes in electrocoagulation cells. Selenate on the other hand is difficult to remove. It is often incorrectly assumed that electrocoagulation is suitable for removing both selenite and selenate. Selenate removal efficiency by electrocoagulation is low and the amount of waste residue produced high. In contrast, BioteQ’s Selen-IX™ process removes selenate very efficiently and produces a much smaller amount of stable residue. The process combines selective ion exchange with electro-reduction of selenate in electrocells that physically resemble electrocoagulation cells but are designed and operated differently. This paper summarizes four years of pilot scale demonstration on a wide range of mine waters and discusses the key benefits and limitations of Selen-IX™. The pros and cons of combining ion exchange with electro-reduction in comparison to direct electro-reduction of selenate are also reviewed.INTRODUCTION Selenium in Mining and Mineral Processing Effluents Similar to sulphate and metals, selenium presence in mining and mineral processing wastewater originates from minerals contained in the mined deposits. Therefore, no organoselenium species are typically present in these kinds of waters and inorganic species including selenite (SeO32-), selenate (SeO42) and elemental selenium account for the majority, if not all, selenium present in these streams. Elemental selenium is not always present in mine water but is often contained in smelter wastewater. To comply with new environmental regulations, a successful water treatment plant must remove selenium from all these forms effectively and economically without generating by-products that are difficult to dispose of or manage. Elemental selenium can be dealt with using filtration or gravity separation in clarifiers often assisted by flocculants and/or coagulants. Mine impacted waters typically contain other forms of suspended solids which are removed from water in this way. Once the solids are removed, the selenium species that remain untreated are the dissolved forms. In mining waters this is mostly selenate with small fraction of selenite. In smelter wastewater, the majority could be selenite. It is well established that tetravalent selenium is readily removed from water by using ferric iron co-precipitation at pH > 4 (NAMC SWG, 2010). Ferric hydroxide/ferrihydrite solids act as the adsorbent for tetravalent selenium when it is in one of the ionic forms of biselenite or selenite. This treatment for tetravalent selenium is highly efficient. Therefore, tetravalent selenium removal is generally not an issue and is often easily incorporated into lime neutralization or unit operations such as electrocoagulation used for removing other metals present in mine impacted waters. Another option of dealing with tetravalent selenium is sulphide precipitation in acidic pH which produces SeS2 and can separate selenite from other metals and/or sludge produced at neutral to alkali pH."

Jan 1, 2017

By L. Gonzalez-Sardi, W. McCombe, M. Pearson

Pressure oxidation is increasingly being used for processing refractory sulphide ores and concentrates because it offers highly effective base metal and precious metal extraction while minimizing elemental sulphur, arsenic & mercury emissions. Yet pressure oxidation processes introduce new safety concerns and process risks as demonstrated by a number of safety incidents over the last 20 years, including overfilling, oxygen-metal fires, nozzle/sparger failures, and uncontrolled pressure relief events. Chemical Process Safety regulations in the United States and Canada mandate that companies constructing or operating chemical process facilities perform a rigorous hazard and risk analysis based on either ANSI/ISA-84.00.01 or IEC 61511 safety standards to determine the level of protection required for each hazard in the plant. This paper describes the application and implementation of three (3) unique safety instrumented systems developed by Hatch for ensuring the safe operation of three different pressure oxidation processes.

Jan 1, 2014

By K. R. Nichol

The author points out that corrosion works 24 hours a day, every day. It is an economic reality that the cost of corrosion is inevitable and that its cost should be incurred in the least expensive way. An economic evaluation technique to properly assess its relative impact is the Discounted Cash Flow Method. Various remedial and corrosion control measures are available and these, when coupled with a planned corrosion control program, help reduce the cost of corrosion.

Jan 1, 1973

By D J. McDougall

Due to changes in the solid-state conditions of minerals in the rocks surrounding hydrothermal, contact meta-somatic or metamorphosed ore deposits, positive or negative thermoluminescent anomalies may be found in their vicinity. Several types of equipment which can be used for both quantitative and semi-quantitative measurements of the emission are discussed and compared. Methods of selecting, preparing and testing samples to ensure reproducible results are outlined, along with the kind of data which can be obtained from different types of equipment. The normal thermoluminescence of rock-forming min~ erals in the common rock types is noted, and variations in the solid-state conditions in the wall rocks which will cause marked increases or decreases of true thermoluminescence are outlined, as well as the thermolum-nescence-like emissions which are present in the vicinity of ore deposits. Introduction T HERMOLUMINESCENCE occurs when certain crystalline materials are heated to temperatures ranging between 180' and 400°C. The light emission can be ascribed to the release of electrons metastably trapped within the crystal lattice, with peak emissions taking place at temperatures which are more or less specific for a particular set of traps; the area under

Jan 1, 1965

By Mori Fresko, Stuart M. Jones Jr

"This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded.A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.INTRODUCTIONThis paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide. The list is maintained by Stuart M. Jones, Jr. (author), and is included in the appendix. This list has been the inspiration for similar papers in the past several SAG Conferences. Updates have been solicited from all major mill manufacturers and most have responded. Information from this list is compiled to illustrate the growth of the AG/SAG mill market and the use by industry and selected geographic areas. It covers the market growth through the end of 2010."

Jan 1, 2012

By J. Marks

The measurement of greenhouse gas (GHG) emissions from primary aluminium production and inventory of these emissions of carbon dioxide and PF Cs have become an important issue for primary aluminium producers. Most global producers have either voluntary emission goals or emissions limits established through national regulatory requirements. International good practices for inventory of these emissions for national governments are established through the Intergovernmental Panel on Climate Change (IPCC). The current good practices, last updated in 2000, are being revised and are expected to be adopted by governments in the spring of 2006. There are a number of changes expected in the guidance that will impact how facilities account for their GHG emissions. This paper describes the changes to the guidance and the implications of these changes for aluminium producers.

Jan 1, 2006

By Janos de Warga

"After a short introduction to the history of the semi-conductor theory, the paper describes the principles of electron and hole flow in the semiconducting materials, the operation of the PN junction, and the rectification process in multi-layer devices (diodes and SCR's). The various methods of purification and zone-refining of the silicon are illustrated prior to the discussion on the most commonly used junction-forming processes (alloying, diffusing, etc.). Modern device fabrication and packaging operations are illustrated. Factory testing, evaluation, electrical parameters and guaranteed rating characteristics are listed. It is explained in this paper how the various device parameters affect the electrical performance of the finished unit and how the finished unit characteristics (turn-on, turn-off time, etc.) will influence the equipment rating. In concluding, some typical items of equipment are highlighted, and the applications of these semiconductor rectifiers in the chemical, mining, pulp and paper, and steel industries, etc., are dealt with."

Jan 1, 1967

By J. D. Robertson

An in situ water sampling device has been developed to measure biologically-available or “labile” metals in natural waters and effluents. The active mechanism involves the use of a polyacrylamide gel layer to quantitatively control metal transfer to a trace-metal-adsorbing, gel-imbedded resin. Because the resin only adsorbs free metal ions (the gel sampler methodology is a kinetic speciation technique), and because metal bioavailability is related to the free-ion activity, the device provides a direct measure of the biological-availability of metals in the environment sampled. The prototype consists of a layer of ion-permeable polyacrylamide gel which separates the solution to be sampled from an ion exchange resin. Because approximately 90% of the polyacrylamide gel is water, mass transport through the gel is diffusion-controlled, and is therefore well defined. Metal ions are rapidly bound by the resin, creating a steep concentration gradient in the gel. The amount of labile trace metal that accumulates on the resin can be related directly to the concentration of the metal in solution, the exposure time and the molecular diffusion coefficient of the labile species. In addition, the passive nature of this device affords it the potential to address many of the limitations presented by conventional sampling methods, such as sample contamination introduced during collection or filtration and changes in trace metal speciation prior to analysis. Laboratory studies and limited field trials indicate that the sampler behaves as anticipated and illustrate that biologically- available metal concentrations in many environments are a small fraction of the total concentrations and often significantly less than the dissolved concentration. The implications of this on regulatory criteria are discussed. Additional field trials and correlation with bioassays are currently underway.

Jan 1, 2000

By Ray Mason, Damien Label, Howard Bernier, Kevin McDermott, Kevin Coombs

"GeneralWabush Mines is an unincorporated joint venture of seven steel companies and Pickands Mather & Co. The mining and concentrating facilities are located in southwestern Labrador and the pelletizing and shiploading facilities are at Pointe Noire, 200 miles south, near the town of Sept-lies.The operation is based on a 5 ½ sq. mi. specular hematite deposit with a reserve of 375 million tons of concentrate. Annual production capacity is rated at 6 million tons of pellets per year. The final upgrading process utilizes high-tension separation of silica following wet autogenous grinding, spiral gravity separation and fluo-solids drying. The concentrate is railed in closed cars to Pointe Noire. The concentrate is reground dry and pelletized on Dravo Lurgi travelling grate machines to produce an oxide pellet with 65.5% Fe, 3.0% Si02, 1.95% Mn and 93.5% Tumble Index.HistoryPlant operations commenced in 1965 with a concentrator capacity of 5.3 million tons per year and a pelletizing capacity of 4.8 million tons per year. The original facilities for classifying the crude ore into fine and coarse fractions for storage purposes before reblending as autogenous mill feed were found to be unnecessary and were by-passed after plant startup. Capacity of the operation was increased to 6.0 million tons of pellets per year in 1968. This increased capacity required the installation of an additional160 cleaner spirals in the ore dressing plant, a new 5000 hp ball mill, three balling circuits and increased cooling air capacity in the pellet plant.In 1970, the regrind circuit in the pellet plant was converted to dry grinding and a significant reduction in grinding media consumption and maintenance costs was realized. A ninth grinding mill of 5000 hp capacity was installed to compensate for the reduced capacity in going from wet to dry grinding."

Jan 1, 2000

By K. Turgeon, D. Larivière, L. Whitty-Léveillé, J. -F. Boulanger, C. Bazin

"The processing of ore containing rare earth elements leads to the production of an impure solution of these elements. The separation of the rare earths from the impurities and the production of individual elements is usually carried out by solvent extraction. The effectiveness of the extraction conditions and of the reagents is generally tested in the laboratory. This paper deals with the processing of results from solvent extraction laboratory tests planned to generate data redundancy. A method is proposed to take advantage of the data redundancy by accounting for the pH variation during the extraction. The parallel processing of several tests also allows estimating the equilibrium constants for the extraction. The proposed method produces equilibrium constants that are more reproducible than values estimated using conventional approaches. The method is illustrated with solvent extraction tests conducted on synthetic solutions of rare earth elements.INTRODUCTIONThe processing of ores containing rare earth elements (REE) usually includes the production of a concentrate of the minerals carrying the REE. These minerals, for instance monazite and bastnäsite, contain the 14 elements from La to Lu plus yttrium and scandium. As an example monazite has the general formula of (La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy…Lu)PO4 with a typical lanthanum content of 20-26%, cerium content of 40-50%, praseodymium of 4-6%, neodymium of 16 to 20%, and decreasing concentrations of heavier elements (Gupta & Krishnamurthy, 2005). During the processing of a REE mineral, it is generally not possible to isolate and separate a single REE from all the rest. The mineral molecules need to be broken (usually via a heat treatment followed by leaching with a base and/or an acid) to produce an aqueous solution of the REE of the ore. After purification of the solution, the REE can be precipitated as a bulk concentrate and sold to a refinery that separates the REE into particular groups of REE such as the light versus heavy REE or into individual elements such as lanthanum, neodymium, or europium oxides to yield value-added products."

Jan 1, 2016

By Paul Guliov

Potash dominates the industrial mineral scene in Saskatchewan accounting for 44% of total provincial mineral production in 1981. More than 7 million tonnes of potash have been produced annualy in recent years; ten underground mines are presently (1983) active. Sodium sulphate and cement are also important mineral products. Construction aggregates, clay products, bentonite, salt, peat moss and sulphur complete the list of industrial mineral products.

Jan 1, 1984

By Y. Guglielmi, C. Gout, P. Henry, P. Dick

The key questions about fault reactivation in shales concern the potential enhanced fluid displacement through a previously low-permeability aseismic shale formation. Here we selected a critically-stressed fault cross-cutting the underground research facility of Tournemire (France) which is located in Toarcian shales. Several inclined boreholes were drilled across the 8.5 m thick fault zone characterized by a fractured damage zone (FDZ) and a central 2.4 m thick complex core (FC) made of multiple shear bands with gouge intercalated with highly fractured lenses. The fault was pressurized using a straddle packer system defining a 2.4m long injection chamber normal to the fault surface. Three fault zone intervals were tested, two in the fault damage zone and one in the fault core. A three-dimensional displacement sensor set in the chamber allowed continuous synchronous coupled monitoring of fault movements, injection pressure and flow rate. An anticlockwise 0.22-to-0.05 mm fault slip was captured associated with a 10-to-100 hydraulic aperture increase of the fault. Preliminary analyses of the experiments show that leakage in the fault zone is controlled by strength and stress magnitude contrasts between the fault core and the fault damage zone. Fault damage zone discontinuities display a much higher peak static friction angle than the fault core shear zones, respectively of 34 and 22° that could be related to complex interactions between healing and sealing processes. Fault core leakage is much more dependent on strain than on effective stress variations. Discontinuous, pulse-like leakage, develops following complex failure processes that may simultaneously take place in the gouge zones and along the large pre-existing discontinuities. Such results may be of importance in evaluating fault seal integrity in oil and gas exploration, production or CO2 storage or underground excavations monitoring.

Jan 1, 2015

By J. Mirza, E. Nicol, J. Lipkowski

Gold passivation in thiosulfate leaching media is a major barrier to its implementation. Addition of Cu (II) into the leaching solution has shown to aid in gold dissolution, but the mechanism by which it acts, and its role in the passive layer, remains unknown. Surface Enhanced Raman Spectroscopy (SERS), in tandem with linear sweep voltammetry, were employed to determine the dependence of leaching currents on mass transport and for fingerprint identification of sulfur species on the surface of gold. SERS leaching experiments were performed using gold nanorod electrodes that showed increased stability compared to other SERS active surfaces.

Jan 1, 2011

By Wm. T. Bray

SYNOPSIS Canadian Refractories, Limited, produce a wide range of basic refractories. The chief raw material use in their manufacture is the magnesite which is mined, and beneficiated in a heavy media separation plant, at Kilmar, Que. This paper describes the underground operation and the plant and explains how the gravity separation of light, siliceous gangue from the ore has changed the mining practice, increased the ore reserves, and improved the chemical uniformity of the crushed ore. HISTORY REFRACTORIES are essential in the production of steel and base metals and in other high-temperature processes. Basic refractories, chiefly composed of magnesia which is obtained by burning magnesite, are used to line and repair basic furnaces. When World War I cut? off the importation of Austrian magnesite, upon which North American industry had depended, domestic sources bad to be found. In Quebec, work was begun on deposits of magnesite at Kilmar, half way between Ottawa and Montreal and about ten miles north of the Ottawa river. By the end of the war substantial tonnages were being quarried and calcined, but, when Austrian magnesite again became available, the industry declined rapidly. In 1925, the National Research Council, in co-operation with the Federal Department of Mines, began an investigation of the industry's technical problems. The result of this research work, which was taken over fully by the Company in 1943 and is actively continued, is that the single product of the early 1920's has been supplemented by more than forty specialized products serving the metallurgical and chemical industries across Canada and in more than thirty other countries.

Jan 1, 1951

By G. Armand, G. Arnold, A. Giraud, C. Auvray

The knowledge and understanding of the mechanical behavior of claystone is of critical importance in the aim of nuclear wastes storage. In this study, specimens of Callovo-Oxfordian claystone (COx) have been obtained from the ANDRA underground research laboratory in Meuse/Haute-Marne (France). This claystone is composed of carbonate inclusions (10-50µm) embedded in an argillaceous matrix (representing expanding clay minerals, such as smectites). The matrix itself is also multiphase and composed of clay aggregates of 1µm-size carbonate and quartz inclusions. This multiphase microstructure leads to a high heterogeneity witch was analysed through nanoindentation test grids. Moreover, the mechanical behavior of the claystone matrix is highly sensitive to humidity and temperature. The nanoindentation tests were performed in a climatic (i.e. temperature and humidity controlled) chamber at relative humidity levels from 50% to 98% and at two temperatures: 20°C and 60°C. In a first step, the curves of indentation were analysed using the commonly used Oliver and Pharr’s approach. Other wellknown parameters as the creep factor were also extracted. In a second step, Fisher-Cripps model (Fischer- Cripps, 2004) and Vandamme and Ulm model (Vandamme & Ulm, 2006) were used to identify viscoelastic properties. A statistical analysis is used in order to extract mechanical characteristics of the different phases. Hardness and elastic modulus decrease drastically with saturation (above 80% humidity) and to a lesser extend with temperature.

Jan 1, 2015

By J. Álvarez, J. Mesías, C. O. Gómez

"Operations routinely run flotation tests in laboratory mechanical cells to determine adjustments to plant operation based on feed flotation response or the effect of new reagents and dosages. The metallurgical results of these tests are certainly affected by changes in bubble size, which simultaneously impact the recoveries of the collection and froth zones. It is known that bubble size depends on the characteristics and operation of the machine in use, particularly on the gas flow rate delivered to the unit and the selected frother type and dosage. Although flotation rate constants have been related to bubble size, bubble surface area flux seems to be a more fitting variable to correlate flotation kinetics and cell performance, as it integrates bubble size and superficial gas velocity effects. However, although some evidence has been provided, a categorical relationship between cell recovery and bubble surface area flux has not been established. Our interest is to demonstrate this relationship to use it as a basis for developing soft sensors to track on-line collection zone recovery in cells. Flotation tests were designed to produce Cu concentrates for a range of bubble surface area flux values, obtained through changes in frother concentration at a constant gas flow rate, and by increasing gas flow rate at the same frother concentration. The tests were run on samples prepared from an ore batch supplied by a local operation, following strict grinding and flotation procedures, with a shallow froth to approximate cell recovery to that in the collection zone. Bubble sizes were determined using the sampling-for-imaging technique developed at McGill. The results unequivocally showed a consistent positive correlation between cell recovery and bubble surface area flux, and significant variations in performance when frother addition and gas flow rate were changed.INTRODUCTIONMineral flotation is a separation process to produce concentrates of valuable minerals by selective attachment of particles to the surface of bubbles. The process is carried out in machines where air is injected through a mineral pulp to form bubbles, and operated to create two zones: a bottom one (collection zone) where bubbles are continuously generated under conditions adequate to form bubble-particle aggregates by collision of the rising bubbles with suspended particles; and a top one (froth zone) where bubbles and bubble-particle aggregates continue to rise while concentrating and forming a froth layer for water and entrained particles to drain back to the collection zone, before overflowing as a concentrate stream. The phenomena occurring in these zones are complex and, in many cases, interactive, as they simultaneously affect stages of the particle separation sequence occurring in both zones. Although there have been significant advances in instrumentation to characterize particle and bubble populations, these have not resulted in knowledge to explain or models to describe phenomena from fundamental principles. Measurements continue to be limited to the development of empirical models for predicting the effect of operating variables on performance."

Jan 1, 2016

By J. J. Benitez

MIBC (methyl-isobuthyl carbinol) was previously shown to enhance significantly sylvite flotation when used at the stage of preparation of amine dispersions. In this paper Atomic Force Microscopy (AFM) is used to study the effect of MIBC on deposition of octadecylamine (ODA) on the surface of mica. The AFM images indicate that amino terminated, and therefore hydrophilic, deposits of ODA are observed on the mica surface in the ODA dispersions free of MIBC. In the presence of MIBC a methyl terminated (hydrophobic) monolayer is obtained on the mica surface. The transition between the monolayer and bilayer phases is due to the presence of MIBC. Experiments carried out in distilled water reproduced the results obtained from the brine. Working in pure water instead of brine simplifies the preparation conditions and the analysis by AFM.

Jan 1, 2006

By Al Goodier

"This paper discusses the experience of Noranda Mines Limited, Matagami Division, with the vertical crater retreat (VCR) method in the mining of narrow-vein stopes. Although limited to only one stope, the viability of this method at the Radiore No.2 Mine has proven that further use of VCR in narrow-vein mining will be made.IntroductionThe Radiore No.2 property is located east of the Bell River in the southeast quadrant of Isle-Dieu Township, approximately 4.5 km east of the town of Matagami. The new James Bay Highway is 2.5 km north of the property and access to the mine is by a 2.5-km logging road.The property was staked by Radiore Uranium Mines in March 1961 and the sulphide body was first indicated by an E.M. survey. Diamond drilling commenced in the fall of 1961 and was completed by the end of 1962. As per an agreement in 1970, the claims were sold and assigned to Orchan Mines Limited. Subsequently, the property was transferred to Bell Allard Mines Limited, a wholly owned subsidiary of Orchan Mines. Early in 1979, Noranda Mines Limited acquired the property and it is now part of Noranda's Matagami Division.Geology and MineralizationThe deposit is in a band of volcanic rocks north of the Bell River complex. The lens of massive sulphides dips almost vertically and strikes almost east-west. The north contact is essentially sharp against andesite material; the south contact is less well defined, as the massive sulphides tend to grade into more disseminated material.The orebody varies from 5 to 20 feet in width, by 350 feet long and 200 feet in height. The overburden is composed of sand, gravel and clay, varying from 0 to 26 feet in depth. The ore reserves were 153,340 tons grading 1.97% copper and 1.01% zinc including 10% of dilution at zero grade."

Jan 1, 1982