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By Barrie Robb

Outline 1. Mackenzie Aboriginal Corporation (MAC) 2. ACR background 3. ?Learning from Experience? project - What - Why - lessons 3. How Industry could contribute to sustainable Aboriginal communities 4. Concluding words What is the Mackenzie Aboriginal Corporation (MAC)? ? Aboriginal owned ? Established construction capabilities ? Commitment to development of northern resources ? Partners have extensive experience

May 1, 2008

By F. Flynn, P. Downey, G. Ritson

"Bell Creek Mill which has been in continuous operation since 1987 has undergone numerous operational changes in the past three years. The addition of over 2. 5 million tons of resource at over 13 git from Hoyle Pond Mine precipitated an expansion program for the Bell Creek Mill. This paper discusses the major changes that have occurred over the past two years to increase throughput and efficiencies. In addition, the refractory ore treatment options are also discussed.IntroductionThe Bell Creek Mill is located in the Timmins Goldcamp approximately 8km NE of porcupine Ontario. (Fig I.)The mill was originally constructed by Camamax in 1987 to treat the Bell Creek ore at a design throughput of 350tpd. The flowsheet (Fig 2.) consisted of two stage crushing, grinding, thickening, leach and drum filtration with gold recovery by Merrill Crowe.As ore depleted at Bell Creek, the Mill was purchased by Falconbridge to process ore from their Hoyle Pond property. Kinross purchased the Hoyle Pond property and Bell Creek Mill from Falconbridge in 1992.The successful exploration program at Hoyle Pond has led to several expansions and process design changes, with further changes planned over the next twelve months.In 1994, the mine produced 61,865 oz. of gold at an average cost of 197US$ per oz. In 1995 production was 91, 611 oz. at a cost of 187US$ per oz. Projecting the nine months ended September 30, production for 1996 will be 155,000 oz. at a cost of 165US$ per oz.In early 1997, the CIP expansion will be complete, with a target of 175,000 oz. at a cost of 176US$ per oz for 1997. The mill throughput will have increased from 400tpd to 1500tpd between 1994 and 1997.The changes to Bell Creek since 1994 have been numerous with very little of the existing equipment still in operation. The total cost of the expansion to date is 15 million C$. This paper discusses the major projects carried out during in this time. The focus will be to highlight the justification of each project, the design and engineering, some of the initial start-up problems and solutions.Figure 3 shows a plan of the existing mill facility together with the various additions that were carried out."

Jan 1, 1997

By Kevin Phelps, Jason Baird

When dealing with high velocity projectiles, the ability for researchers to accurately and precisely measure the velocity of the projectile is of great value. This report will analyze three different methods of recording high velocity projectiles for: their ability to record velocity data, pros and cons for each method, and any possible bias or limitations that would result. Method 1 uses a Phantom V10 high-speed video camera and a velocity reference screen to record the projectile’s path and proprietary Phantom software to analyze the data and determine velocity. Method 2 utilizes two break screens. This method, consisting of strung copper wire as the break material, is one that has been used in the past by Missouri University of Science and Technology (MS&T) researchers in assisting in finding velocities of high-speed projectiles. Method 3 is a pair of make screens, similar to Method 2 in that two screens were used for each test but relies on a projectile making a circuit between two sheets of metal separated by an insulation layer, to find a velocity. All three methods will be used simultaneously in each shot to rule out any projectile differences in subsequent shots. Projectiles of three different relative velocities, low, medium, and high, will be fired and analyzed to determine strengths and weaknesses of each method.

Jan 1, 2014

By Adam Wright

"Les Mines Selbaie have been producing copper and zinc concentrates from the A-1 ore zone since 1986. This paper reviews major developments in flotation practice over that period. Firstly, ore blending strategies for Selbaie's non-homogeneous polymetallic ore are discussed. The evolution of reagent use is then reviewed, focussing on copper collector trials. A description of Selbaie's flotation columns follows. Finally, past and future developments for process control are outlined.Depuis 1986, Les Mines Selbaie produisent du concentré de cuivre et de zinc provenant de la zone A-1. Cette conférence présente !es développements majeurs en flottation qui ont eu lieu depuis ce temps. Premièrement, la stratégie du mélange de minerai non homogène polymétallique est présentée. L'évolution des réactifs utilises est démontrée, particulièrement !es collecteurs de cuivre. Par la suite !es colonnes de flottation sont presénteés et finalement !es développements futurs ainsi que ceux qui ont eu lieu dans le contrille de procédé sont expliqués.1.0 INTRODUCTIONLes Mines Selbaie, wholly owned by Billiton Metals Canada Inc., is currently mining and processing ore from a polymetallic surface deposit located 288 km northwest of Val D'or, Quebec (fig. 1). The mine produces copper concentrates containing gold and silver as well as zinc concentrates containing silver. 8000 dmt/day of ore is crushed and ground to 80% passing 49 µm, prior to processing by conventional copper/zinc differential flotation. The flotation circuits consist of both conventional and column cells (fig. 2). Detailed descriptions of the mill are available elsewhere in the literature (8,9)."

Jan 1, 1995

By S. Achilleoudes

This paper describes the various factors that contribute to the maximum design pressures acting on box fronts and how these factors influence the mass and economy of box front steelwork. The influence of material density, rock size and moisture content on the incidence of hang ups and mud rushes in the rock pass is also highlighted. The loads acting on any box front are a function of several different parameters. These include natural, operational and excavational parameters. A case study analysis was carried out using UG2 ore and a typical box front structure to demonstrate the relationship between the mass of the box front and the material pressures resulting from variations in the above parameters. Based on the results of this case study, the required design mass of a side mounted box front for a rock pass containing platinumUG2 increases in (close to) linear proportion to % overbreak and is also linearly proportional to the pressure on the face of the box front beyond saturated conditions. The mass of the box front structure also doubles with a 100%increase in over-break which emphasises that a box hole excavation that is as neat as possible will yield a lighter and more econimical box front structure.

Jan 1, 2005

By S. A. Scott

Mintek developed the MinataurTM leach-solvent extraction-precipitation technology as a cost effective, easily operated alternative to conventional gold refining processes. The technology was first commercialized at the Harmony Gold Refinery in 1997 to produce 99.99 per cent gold product and has subsequently led to development of various value-addition steps including the casting of various investment bars, gold wire drawing and gold potassium cyanide powder production. In addition to refining gold to high purity, if an appreciable amount of silver is present in the feed material it is also refined to 99.99 per cent purity. The major advantage that the Minataur? technology has over other gold refining processes is the relatively low gold lock-up and reduced operating costs. The operating cost1as at April 2001 for the expanded Harmony refinery (24-ton per annum gold production) was approximately half that of conventional smelting and toll refining. The extractant employed for solvent extraction is relatively cheap and highly selective for gold, making the technology attractive in situations where significant quantities of platinum group metals or base metals are present.

Jan 1, 2004

By G. Wendel

Uranium is a naturally occurring radioactive material in the earth?s crust. Geological processes have resulted in concentration of uranium into ore mined for its gold content in South Africa. This uranium is present in the form of discrete particles of uranium minerals, generally oxides, which are normally insoluble. Chemical and physical processes during gold mining and extraction, particularly when carried out in conjunction with uranium extraction and sulphuric acid manufacture, act on the uranium minerals and the radioactive decay products of uranium. This may result insignificant accumulations of radioactive materials in certain parts of the process. There are a number of naturally occurring radioactive materials in the earth?s crust, such as Uranium-235, Thorium-232, andPotassium-40. This paper focuses on Uranium-238, together with its decay products, and how they affect the gold mines. Water plays a significant role in the redistribution of radionuclides, both as a physical transport medium, and as a solvent in which chemical reactions take place.

Jan 1, 1998

E. T. DUMBLE, Houston, Tex.-This paper is a continuation of one that was published by Mr. Garfias, I believe, in the Journal of Geology, 1912, in which he gave the results of his investigations in Mexico, showing that the basalt extrusions frequently did not come up as cones. but reached the surface as a small neck and then mushroomed out into a sill, penetrating the beds both in limestones and in shales. He has continued his investigations to show that as these basalt protrusions came up they forced the strata into a funnel shape at the top instead of throwing them out altogether. While this may be true concerning these particular beds, there are other places at which the basalt does appear clearly as cones and dories, and there the funnel structure does not exist. We know that the sills are there, because we find them in the wells. In one well that I know of. we found a 2-ft. sill of basalt at about 1600 ft. and oil below it at about 2100 ft.; others have gone through similar beds. We also know that there. are cones, because north of the Ranuco River one well struck basalt at about 800 ft. and continued in it for several hundred feet-did not pass through it at all. This paper of Mr. Garfias will give us considerable help in that oil field. W. E. WRATHER, Wichita Falls, Tex.-I would like to ask for information as to the temperatures of Mexican oils. I have heard a number of conflicting reports about the high temperatures of the water and oil, and the relationship between them.

Jan 1, 1918

The validity of a steady state assumption made by Adams and Nicol (1986) in the modelling of the elution of gold from activated carbon was investigated. It is shown that the accuracy of the steady state approximation is dependent, not only on the magnitudes of the solution flow rate and reactor volume, but also on the lumped elution rate constant. Under the experimental conditions used by Adams and Nicol (1986) the steady state assumption was inaccurate. This could be circumvented in this instance by applying a rigorous general model which accounts for unsteady state behaviour in the solution and in the activated carbon to the experimental data.

Jan 1, 1997

By R. W. Bruhn

The objective of the study is to examine the apparent influence of soil and near surface rock strata on the severity of damage experienced by surface structures subjected to mine subsidence. The report discusses: 1) modes of ground movement that might complicate or be confused with mine subsidence; 2) prevailing concepts concerning mine subsidence in the Northern Appalachian Coal Field and Illinois Basin; 3) apparent influences of soil and near surface rock strata on the character of subsidence-related ground movements; 4) classifications and criteria for characterizing damage due to ground movements; and 5) types of subsidence damage experienced by homes above active mines in western Pennsylvania. Presented is a damage classification system incorporating a severity index for characterizing subsidence damage to homes with basements above active mines. A series of case histories illustrate subsidence damage to structures above active and abandoned mines.

Jan 1, 1983

One of the most important factors leading to the success of a cement plant is its location. A multicriteria decision-making method is used to rank alternative plant locations. The set of criteria is established and corresponding criteria should be established for each case study, although this multicriteria decision-making approach has broader applicability. In this paper, the analytic hierarchy process (AHP) with 5 criteria is used to develop a location evaluation hierarchy for an alumina?cement plant in East Azerbaijan province of Iran. Five alternatives for the plant location are evaluated. The main criteria are transportation, water supply, power supply, fuel supply and land. Other criteria have the same importance as these five alternatives. The alternatives are ranked by a multicriteria method and the best site is proposed. Keywords: plant location; multicriteria decision-making

Jan 1, 2005

By Kot F. v. Unrug

The present combination of coal market prices and reserves, situated in the Central Appalachian Coal Field, is such that mining of smaller coal reserve blocks has become economically attractive. In above drainage deposits, and particularly under mountain ridges, overburden depth can be changing within a wide range. Mines operating in these deposits are usually developing mains along the center of the ridge, with panels projecting from the mains towards the outcrop. Due to changing topography, proximity of the outcrop, and related cover depth, the panels have various lengths. In this reported case study, a mine in Pike County, Kentucky, along the Kentucky ?West Virginia border, difficult ground conditions were encountered, during the development of the mains, under shallow cover, along a narrow mountain ridge. An area having unusual density of vertical joints was encountered. Mining operations were suspended because of roof stability concerns. The ground conditions were studied, analyzed, and control measures proposed to ensure safe passage through the difficult roof area of the mine. The advancement of the mains, through this area of challenging ground conditions, was successfully completed. In this paper, ground conditions are described, with an explanation of the geologic process contributing to their formation. It is interesting to note that similar locations were predicted by the authors, to be encountered in the same mine, based upon the experience gathered from studying conditions of the case described within this paper. When approaching the predicted locations, stability problems appeared to be even more challenging than those encountered previously. Due to changes in the coal market, mine management chose to move the affected mining section to another area of the mine having better coal quality. The advancement of the mains, through the difficult ground conditions, was temporarily postponed. Based upon the analysis of a probable kinematical mechanism of blocks in the mine roof, ground control measures were proposed. The actual application of these principles proved to be appropriate, ensuring safe passage through the difficult ground conditions encountered in the mine.

Jan 1, 2006

By James F. Kvitkovich, George V. Weisdack

Longwall mining techniques were introduced into U.S. bituminous coal mining operations in the early 1960s. These techniques were gradually adopted by many mines during the 1970s. By 1983, considered to be the peak of the longwall mine census, there were 118 active longwall faces in 79 coal mines throughout the United States. Beginning in 1984, longwall faces began a decline in numbers that has continued to the present day (Fig. 1). The geographic distribution of longwall faces today is shown in Fig.2 according to region. A breakdown of recent longwall mine production by region is shown in Table 1. An approximate breakdown of present longwall face installations by product (metallurgical and steam) is shown in Table 2.

Jan 1, 2005

The results of precious metal exploration carried out by Amoco Minerals New Zealand Limited over EL 33-137 in the Longwood Range, Southland, are described. Widespread gold and platinum in alluvial deposits on the perimeter of the range and anomalous gold in stream sediments on its southern and south western flanks indicates that the precious metals were probably derived from erosion of the mafic rocks of the Longwood Complex.

Jan 1, 1983

By Douglas Anderson

Even though there is always a feeling of anticipation before a blast is detonated, most blasts are part of a day’s work. Once in a while there is an event that impresses even the most jaded blaster. Few blasts have had the impact of the Kingdome implosion in March of this year. Fortunately for both the Seattle area and the explosives community, the “impact” of the implosion was far less than many local residents had feared. This outcome, of course, was not by chance, but the result of careful planning and design. An urban implosion requires a mix of engineering, logistics, and public relations. Unique challenges on this project tested the resourcefulness of the entire team.

Jan 1, 2001

By D. Simon

This paper studies the effect of binder type and content on the early age development of cemented paste backfill (CPB). The early age development of the mixtures is analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). These tests show that the early age development of CPB is sensitive to changes in the paste composition. The properties of the CPB depend on the cement content and hydration time. The quantity of hydration products increases with hydration time for all of the mixtures containing cement. However, the high cement content pastes (at least 50% PC) exhibit complete coverage of the PC grains and mine tailings by C-S-H, while the low cement content paste shows scattered coverage of the PC grains and mine tailings and a higher void ratio.

May 1, 2007

By L. Ozdemir, M. Cigla

This paper presents and discusses some of the computer models developed and currently used at the Earth Mechanics Institute (EMI) of the Colorado School of Mines (CSM). These include the performance models for full and partial face machines. Examples of input and output of these models will be illustrated for typical mining operations by using machines such as Tunnel Boring Machines (TBM), Continuous Miners (CM), Marietta borer miners and longwall drum shearers. The general approach to modeling and the available models are discussed and some examples of these models are presented. The comparison between the estimated and achieved performance, as well as the degree of improvement in the performance due to balancing and modification in cutterhead design are also discussed.

Jan 1, 2000

By C. J. Wilhelm

Brine produced from subsurface formations may be employed successfully instead of fresh water as a flooding, medium in the secondary recovery of oil. The feasibility of this substitution has been proved in the shallow "shoestring" area of eastern Kansas and northeastern Oklahoma, where the supply of fresh water often is limited. In this procedure all brine produced with the oil is returned to the formation and thus is prevented from contaminating streams and fresh-water supplies. This report includes a detailed description of a "flood project" in eastern Kansas studied by the Bureau of Mines. In an attempt to determine whether brine, when handled properly, can be used as effectively as fresh water in flooding oil from partly depleted, formations, an analysis was made of all .own conditions that influence flooding.

Jan 1, 1941

By Donald J. Olson

The North 27th St. ISS Extension tunnel will, under present plans, be the last constructed section of Milwaukee Metropolitan Sewerage District?s (MMSD?s) existing deep tunnel system. The 6.5 m (21 ft) finished diameter tunnel is approximately 3,260 m (10,590 ft) long and is located in NE Milwaukee County. When disputes over the pro-cesses to be used in owner-directed pre-excavation grouting in rock threatened the completion date stipulated between MMSD and the State of Wisconsin, the MMSD and J.F. Shea, the contractor, entered into a unique agreement. Shea accepted responsibility for all shaft and tunnel grouting and water control during the project in exchange for settlement of claims related to grout quantities and perceived delays. This significantly reduced risk for the MMSD and helped ensure the stipulated completion of the project.

By J. D. Doll

MSHA has promulgated a rule to limit the exposure of underground metal/nonmetal miners to diesel particulate matter (DPM). In May 2008, the final personal exposure limit will be lowered to 160 µg/m3 total carbon. To comply with this rule, mine operators are implementing a variety of control technologies. In this study two types of control technologies (ventilation and cabs) which are being implemented in limestone mines were investigated. Two stone mines in this study use large diameter propeller fans for main mine ventilation and direct the air to the faces using auxiliary fans, stoppings, and long pillars while bypassing the old mine workings. NIOSH measured for sub-micrometer elemental carbon (EC) using SKC DPM cassettes (analyzed using NIOSH 5040) and a near real time instrument. With the present ventilation and the number and type of vehicles used, the concentration of EC from DPM at the working areas was at or below 400 µg/m3 for both mines and about 166 µg/m3 and 251 µg/m3 at the returns. The real time data showed that the ventilation was reaching the working areas and effectively diluting the DPM. Environmental cabs were also used to reduce DPM exposures in three underground limestone mines. Using NIOSH method 5040 and near real time EC instrumentation, NIOSH sampled inside and outside of a loader cab at one of these limestone mines to determine the effectiveness of the cab. The cab was found to be over 90% effective in removing DPM as long as the cab system was properly maintained, and doors and windows were closed.

Jan 1, 2009