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By A. E. Taylor, A. S. Judge, P. T. Lafleche

"Resource development in northern Canada has special requirements which derive from the unique environmental and eco-logical nature of the northern environment. In this paper several case histories in which the Permafrost Research Section of the Geological Survey of Canada (GSC) has participated are used to illustrate how geophysical methods may be used to address some of these considerations. Although some of these examples were developed while examining problems directly related to oil and gas development and transport in frontier regions, such or similar methods also have application to mining problems.IntroductionA critical parameter is the distribution and thickness of permafrost, which in northern Canada varies from being a few metres and discontinuous at the southern limit to thicknesses in excess of 700 m in the Arctic Islands'!'. Figure I is a schematic diagram of typical ground thermal conditions in a permafrost zone. The upper zone is defined by an active layer which undergoes a seasonal freeze/thaw cycle. In the simplest case, the ground remains permanently frozen below the active layer to the depth of the O°C isotherm, which is defined as the base of the permafrost. Water chemistry, pore structure and pore or grain size may cause the base of the frozen ground to be above the permafrost by up to 100 m(2). Ice can be found within the permafrost in the pores of solid rock or sediments, as massive ice within unconsolidated sediments or as ice lenses within fissures in a solid rock mass. The mining technique used in these conditions, whether open pit or underground, can differ considerably from that used in southern Canada. In the high Arctic, for instance, the dry drift method is feasible underground in the permanently frozen host rock. The frozen nature of the wall rocks can obviate water-related problems."

Jan 1, 1987

By Andrew P. Jarosz

The present computerized mine planning systems use CAD-like and Data Base Management System (DBMS) environments for the handling of numerical, textural, and graphical data. These two environments are usually integrated, that the data provided by the DBMS are linked to any graphical element rendered by the CAD system. The subsidence monitoring, analysis and prediction process should be integrated with the mine design process. It should allow for the assessment of impacts of mining on surface, surface utilities, and structures. It should also provide for the measures to control mining, that will create only acceptable levels of negative impacts on the surface. The common data base, and graphical capabilities of the CAD interface, may be used with great advantage for both systems. The findings of the subsidence engineering modulus should be directly incorporated into the mine design system, and vice versa. In this paper the author suggests guidelines for the development of the comprehensive computer system, able not only to predict the vertical and horizontal components of the ground movement, but also assess the induced surface damages, and costs related to subsidence prevention and compensation.

Jan 1, 1995

By Petrus Christiaan Pistorius, Makunga Daudet Seke

The flotation response of a Pb-Zn sulphide ore from the Rosh Pinah Mine (Namibia) was studied in the presence of inorganic depressants such as sodium cyanide and zinc sulphate. Poor flotation selective was observed in the rougher concentrate of the galena circuit despite the use of excessive amount of sodium cyanide. Batch flotation tests have shown that the use of cyanide alone is not efficient for the depression of sphalerite from the Rosh Pinah ore when milling is carried out according to the current plant particle size distribution. The use of both cyanide and zinc sulphate improved the selectivity between galena and sphalerite much better than cyanide alone. Flotation selectivity is limited by the mineralogical texture of the Rosh Pinah ore sample. Microscopic analysis has shown that the presence of sphalerite in the galena concentrate is also due to poor liberation between galena and sphalerite, especially in the middlings. Hence selectivity could be improved by regrinding the rougher concentrate prior to the cleaning stage. Keywords- Sulphide ores, Flotation, Flotation depressant, Mineralogy.

Jan 1, 2005

By Descour Jozef, Suguru Shirasagi, Takuji Yamamoto, Koji Murakami

For TBM tunneling no visual inspection of excavated ground is possible. This may hinder the high-speed excavation, particularly in complex ground conditions. The TBM Excavation Control System was developed for better prediction of geological conditions ahead of the tunnel face during excavation. The seismic reflector tracing produces volumetric images of anomalies in the ground in “near-real time.” These images are verified using logging data from pilot boring and TBM driving data, to improve reliability and precision of ground mapping. Also good correlation was obtained between the rock strength index computed from TBM data, and one derived from volumetric seismic images.

Jan 1, 2007

By Jana Dobrovska

The paper deals with new approach for measurement and evaluation of chemical microheterogeneity of elements in polycomponent metallic systems (i. e. steels, Ni-alloys). The method is based on the original mathematical model for determination of distribution curves of dendritic segregation of selected elements and on the original mathematical model for determination of the effective partition coefficients of these elements in the structure of analyzed alloy. Application of the method at research of chemical heterogeneity of continuously cast steel slab is also presented. The original results of measurement of dendritic microheterogeneity of eight elements (Al, Si, P, S, Ti, Cr, Mn and Fe) in structure of nine zones of a transversal section of slab are given.

Jan 1, 2006

By Paul S. Goodman

Volume I This report presents the first national survey of miners' attitudes and opinions about their-work. The goal is to present attitudinal data that bears on coal production. Interviews were conducted in 26 mines with 2,000 miners. High levels of cooperation were exhibited by management, union and the employees. Data are presented about miners' attitudes about general aspects of their work such as pay, supervision, their jobs, etc. Another section of this report reviews opinions about specific aspects of work performance. Recommendations are presented.

Jan 1, 1985

By E. J. Gleim

A list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1942, was published in Bureau of Mines Information Circular 7207.3/ The list of that date was complete as to equipment then available and in current use. Information Circular 7240,4/ published as a supplement thereto, listed equipment approved curing the calendar year 1943. The present list is another supplement covering approvals issued during the calendar year 1943. The items are numbered to indicate the consecutive order in which each type of machine or device was approved in its particular classification. Thus, Information Circular 7207 gave 19 drills and drilling machines on the Bureau's active list. No additional approvals were given in 1942, but the three issued in 1943 bring the total to 22. Item 102, under Loading Machines and Conveyors, also appeared in Information Circular 7207, and items 120 and 124 appeared in Information Circular 7240. These numbers are repeated here to show that approvals were granted during 1943 for additional voltages on machines previously listed for one voltage only. Equipment listed in these circulars is approved by the Bureau of Mines only when found upon inspection and test to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal-mining industry. The use of such equipment in mines known to be gassy, as well as in those that may become so, is earnestly recommended in the interests of safety. This circular is published so that the industry may be kept

Jan 1, 1944

By F. Sillers, R. T. C. Rasmussen

"INTRODUCTION This is the fourth report of investigations dealing with the cooperative tests between the Bureau of Mines and industry on the use of electrolytic manganese in steelmaking. The first report dealt with the use of electrolytic manganese in the manufacture of stainless steel 3/ the second with its use in acid electric steel practice, 4/ and the third with its use in low-carbon basic open-hearth steelmaking. 2/ A résumé of those investigations E7 appeared in the magazine STEEL. 5/ The present report deals with the use of electrolytic manganese in the manufacture of four types of stainless steel and the new Timken 16-25-6 alloy. The Bureau of Mines supplied The Timken Roller Bearing Co. with 62,000 pounds of electrolytic manganese for use in the tests.The electrolytic manganese was produced at the Bureau of Mines pilot plant, Boulder City, Nev., by the process developed by the Bureau and described in Bulletin 463, Operation of Electrolytic Manganese Pilot Plant, Boulder City, Nev., by J. H. Jacobs. J. W. Hunter, W. H. Yarroll, P. E. Churchward, R. G. Knickerbocker, R. W. Lewis, H.A. Heller, and J. H. Linck. The workcarried out under the direction of R. S. Dean, formerly assistant director, Bureau of Mines, and R. G. Knickerbocker, formerly chief, metallurgical branch, as part of a long-range program involving the development, manufacture, and use of manganese from domestic ores. Preliminary arrangements for the plant tests were made by the late A. A. Dow. 7/"

Jun 1, 1947

By H A. Myburgh

The beneficiation of heavy metal oxides, such as iron ore, is usually performed with heavy medium separation in cyclones, static baths and lately with Larcodems. Atomized ferrosilicon is most suitable as a heavy medium at densities above 3600 kg/m3 whereas a mixture of milled and atomized ferrosilicon is suitable at densities below 3600 kg/m3. When operating a beneficiation plant at densities higher than 3600 kg/m3 the quality of the ferrosilicon particles is an important factor that influences the control of the beneficiation process. Therefore, it is important to know how the rheology would be affected by the ferrosilicon quality as it also influences the control of the process at these elevated densities. Background The Kumba Resources Sishen Iron Ore Mine in South Africa produces 26.5 Mt iron ore per annum from its beneficiation plant. The ore body consists mainly of laminated and massive type hematite ore that is crushed down to ?90mm before being beneficiated by means of a combination of Wemco drums, Larcodem and dense medium cyclone separators. The need for higher densities When the percentage of high-density gangue2 is higher than normal in the run-of-mine (ROM), a higher separation density is necessary to produce a product to specification. Certain ore types of this quality in the Sishen reserves require a separating density higher than 4000 kg/m3, whereas densities would normally average 3600 kg/m3 when beneficiating ores of normal high-density gangue content. Sink and float tests conducted on the ROM material at Sishen revealed some interesting characteristics. In the waste fraction, (density < 3600 kg/m3) it was found that the %Fe was <21% (Fig. 1). Similarly, for the product fraction (density >3000 kg/m3), the percentage Fe varied between 35% and 67.2%. The bulk of the material (88%) actually had a density greater than 4000 kg/m3 and a Fe content that varied between 63% and 67.2%. At a density interval of 3600 to 4000 kg/m3, the Fe content varied from 37% to 60% with an average of 45%.

Jan 1, 2006

Macraes Mining Company Limited operates a 2.1 million tonnes per annum gold processing plant at Macraes Flat, Otago. This uses a conventional CIL route to treat oxide ore, and a flotation, grind, CIL route for sulfide ore. This paper describes the design and operation of this process plant.

Jan 1, 1992

By David A. Hill

This volume contains a summary of the results of past analyses on U.S. Bureau of Mines Contract No. 80122061 which are relevant to electromagnetic location in mine rescue situations. The analytical results indicated that detection of a trapped miner equipped with a special transmitter is feasible in most situations. Location of the miner by surface measurements is also generally feasible within certain errors. The feasibility of miner detection and the accuracy of miner location have been examined theoretically for a wide variety of situations. Agreement with experimental results is generally good in cases where measurements are available. Personnel involved in the investigation include J.R. Wait (Principal Investigator), D.A. Hill (Co-Principal Investigator), K.P. Spies, A.Q. Howard, and Lana Slusher (Administrative Assistant).

Jan 1, 1974

By P Knight, P A. Walker, H E. Speight

Pushback 8 South is the final cut back on the south wall of the East Pit at BHPBilliton?s Mt Whaleback iron ore mine in the Pilbara region of Western Australia. Development of the cutback commenced in 1999 and is now nearing completion with ultimate pit walls up to 300m high. This paper describes the geotechnical, structural and hydrogeological setting of PB8S, reconciliation between design and slope performance and the slope engineering techniques used to effectively manage the risks associated with the slope. These techniques include slope buttressing and sequential mining with waste backfilling, as well as a detailed program of displacement and hydrogeological monitoring, structural mapping and slope stability assessment. During the course of slope formation recent developments in remote slope displacement monitoring using radar and remote structural mapping using terrestrial photogrammetry have also been applied. Aspects of the PB8S slope management plan are relevant to many large scale open pit slopes. This paper provides geotechnical practitioners with information which may be helpful in managing geotechnical risk in similar environments.

Jan 1, 2006

By F. Stober, D. Wanblad, J. Ndlovu, L. R. Nelson, L. P. S. de Villiers

The single six-in-line furnace of the Polokwane Smelter is the largest installed high-intensity furnace for platinum group metals (PGM) base metals sulphide smelting in the world. The furnace employs state-of-the art technology to deliver a planned throughput of 650 000 t/a dry concentrate at a design 68 MW power input. This furnace, at double the capacity of previously existing PGM furnaces, offers low unit operating and capital cost through the resulting economies of scale. Key features of the design include:

Jan 1, 2005

By Christopher J. Bise

INTRODUCTION Traditionally, the purpose of mine ventilation has been defined as diluting, rendering harmless, and sweeping away hazardous gases which may accumulate in the mine workings. In addition, the ventilation sys- tem must keep the mine air as close as possible to the composition of the outside air in order to provide a healthy environment for mineworkers and to prolong the useful life of mine equipment. When plans are being developed for opening a new mine, sound engineering dictates that a calculated estimate be made of both the maximum air quantity requirement and the accept- able mine pressure (head) loss related to the under- ground layout and projections. For efficient mine ventilation, the two problem areas that demand constant attention are (1) the control of fugitive air (through short circuiting or leakage) and (2) the provision of ample airway capacity. Fugitive air is that quantity of air which enters the mine but short-circuits the mine ventilation system through improperly constructed stoppings, doors, overcasts, etc.; it represents an investment in power consumption (to move the air by the fan) while providing little, if any, return on the investment. Typically, efficient mines are those that can deliver 50% of the air handled by their fans to the working faces. Paying close attention to a new mine&apos;s ventilation system at the outset can provide numerous benefits during the later stages of mine development. It has often been noted that the main cause of trouble in many mine ventilation systems can be found within a radius of 2500 ft from the fan installation. Ample airway capacity is essential to maintain the mine&apos;s head loss within manageable limits. Similar to an industrial ventilation setting, the mine&apos;s headings are the ductwork for the handling of air. The difference between normal industrial ventilation and mine ventilation is apparent when more capacity is needed; a plant can install new or larger ductwork, but it is difficult for a mine to install new entries or enlarge existing entries. Air velocities are usually maintained under 800 fpm to limit the stirring up of dust in the intakes. With this in mind, it is usually simple to estimate the number of entries required in the ventilation system. The problem that often arises, though, is when the system&apos;s capacity is overestimated and the required head loss to achieve the desired quantity is excessive. Experience has shown that problems are often encountered when the mine&apos;s condition requires much more than three inches of water gage to ventilate the mine on a day-to-day basis. Thus, if proper attention is not paid to these parameters in the preplanning and initial development of a new mine, it may take an extremely high water gage to achieve the ultimate quantity. This chapter will not delve deeply into the theory of mine ventilation; many other books have been writ- ten on that subject. Instead, the following sections will point out the important considerations that should take place before the development of a mine ventilation system, as they relate to normal industry practice. FUNDAMENTALS OF AIRFLOW Volume Versus Water Gage The common method of measuring ventilation pressure is in terms of inches of water gage (wg); one inch of water corresponds to a pressure of 5.2 psf (pounds per square foot). Further, airflow follows a square-law relationship between volumes and pressures where, as shown in the previous section, a doubling of quantity requires a quadrupling of pressure. Table 1 shows how heads and quantities are related. Using Table 1, it is readily apparent that, for the same mining conditions, an increase in pressure from one inch wg to three inches wg results in only 34,640 cfm when the initial quantity is 20,000 cfm. Pressure Losses Pressure losses in mine ventilation systems are caused by friction between the heading walls and the air stream and by shock losses due to abrupt changes of the air stream caused by obstructions. The common pressure-loss formula for mine ventilation is: [ ] where H is the pressure loss in inches of water gage, K is the coefficient of friction, L is the length of the airway in feet, 0 is the airway perimeter in feet, V is the air velocity in feet per minute, and A is the cross-sectional area of the airway in square feet. Table 2 lists the US Bureau of Mines schedule of friction factors (K) for mine airways. Recent research indicates that the values of K are slightly less for coal mines than those presented in the USBM Schedule, and Table 3 should be consulted in this instance. It should be

Jan 1, 1986

The zinc-lead lode at Rosebery, on the West coast of Tasmania, has a total length of over 4000 ft. It consists of five elongated lenses parallel to the foliation planes of the quartz sericite schist, and is situated at the junction of the quartz sericite schist and a thin belt of slate. The lenses consist of massive, fine grained sulphide ore, with small amounts of quartz, barite, sericite and chlorite, and they terminate in masses of low grade ore. The gangue minerals increase in quantity in the low grade ore which includes small quantities of the manganese garnet, spessartite. The schist walls of the lenses are in places impregnated with lode minerals to a degree sufficient to permit them to be regarded as economic ore.The ore-bodies have developed from incoming mineral solutions by the replacement of the quartz sericite schist and are localised where the ore solutions have been confined by a relatively impervious slate band. The early stages of replacement of the schists are signified by the development of pyritic bands which are succeeded by a strong development of zinc blende. With ptogressive crystallisation, the character of the mineral solutions gradually changed and the development of galena, and its associated bournonite, became more important in the later stages.Remnants of the replaced schist, in the form of isolated wisps and schlieren of sericite and chlorite, are present in the ore body, more noticeably in the pyritic specimens. An important feature of the ore is the association of small ogllantities of gold with trahedrite.

Jan 1, 1934

By M Sherman

The challenge facing the engineering provider is to calculate throughput rates when faced with disparate specific energies calculated by different testing methodologies. Typically, an ownerÆs team would expect that the throughput calculations be checked using more than one method, therefore it is inevitable that there will be differences, based on which methodology is used. This engineering challenge is exacerbated by the continuing evolution of contemporary circuit configurations such as two stage pebble crushing with or without high pressure grinding rolls (HPGRs) as the second stage, or second stage pebble crusher product reporting to the ball milling circuit, etc.This paper is a companion to the paper first presented at SAG 2011, which showed that the Bond Indices are an excellent tool for estimating the specific energy requirements for semi-autogenous grinding (SAG) mills in single-stage SAG milling (SSS) circuits, SAG and ball mill circuits (SAB) or SAG and ball mill circuits with pebble crushers (SABC). This paper presents how the Bond Indices have been used to calculate ball mill specific energies, and therefore throughput rates, for SAG mill based circuits. Once the ball milling specific energy is known, tower mill and vertimill energy requirements can also be calculated. It is noteworthy that the method presented in this paper does not require the use of any unpublished correction factors: the proposed method uses the Bond parameters and equations published by Rowland in 1982.CITATION:Sherman, M, 2013. 21st century bond, in Proceedings Iron Ore 2013 , pp 309-312 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Raymond Philippe

Background ?Hatch Water has worked with most major mining companies in Chile on water supply and optimization projects ?Many(copper) mining projects are located in Northern Chile, which hosts the driest desert on earth Water supply options in Northern Chile ?River ?Availability/Rights ?Well(Brackish) Water ?Availability/Rights ?Municipal Wastewater ?Water rights ?Volume ?(Desalinated) Seawater ?Infinite source ?Cost depends on distance and altitude ?Recycling/Reutilization ?Water losses All these options present water quality issues

May 1, 2009

By Edward M. Dowey

The concrete lining for a long 8.05 km (5 mi) section of New York City Water Tunnel No. 3 was cast in place. The contractor, Grow-Perini-Skanska, placed over76,841 m3 (100,505 cy) of concrete, pouring 24 hours per day, 5 days per week. The concrete was dropped 204 m (670 ft) to the tunnel level, transported by rail to a concrete remixer and pump, and placed in 146.3m (480 ft) of full circle forms. Some of the many challenges include the sheer magnitude of the job, navigating through drifts, a raise and curves, dealing with ground water inflows, and placing the concrete within time limits.

Jan 1, 2001

By S. Fuentes, J. Cáceres

"During the past fifteen years, mines utilizing the block caving method have improved performance and systematically reduced total mining costs.This paper describes improvements in mine design, mine planning, and mine management, including methods enabling the Chilean and international mining industry to ensure cost savings and productivity growth while using the block caving method. These improvements have encouraged the re-evaluation of underground operations at operating and closed open pits, and challenge surface mining applications as the only low-cost mining method. This paper describes a strategy to estimate the optimum open pit to underground transition time during the life of a mine. IntroductionDuring the last fifteen years, block caving mines have experienced huge changes in designs, planning and administration. These changes have permitted operators to drastically reduce costs, improve equipment productivity, and improve overall business performance. As a consequence of this situation, the block/panel caving mining system is challenging actual open pit operations to maximize the net present value (NPV)."

Jan 1, 2004

By R. R. Lowery

This project was proposed to provide information on the hazards associated with arc melting of thorium. A general air-sampling analysis was made to determine the separation, concentration, and distribution of thorium daughter (decay) products throughout arc melting, machining, and forging processes of a thorium handling facility. The value of well coordinated health physics program is stressed in connection with potential health hazards and personnel protection. Building, equipment, and exhaust ventilation requirements for such a facility are discussed. Special handling methods are described for thorium. INTRODUCTION The Bureau of Mines at the Albany Metallurgy Research Center has been involved in handling the naturally radioactive metals, uranium and thorium, for several years. Cooperative work for the Atomic Energy Commission has been carried out with thorium metal, and as a result the concerned laboratories of the Center have accumulated experience on the hazards associated with this metal. This report details the radioactive hazards arising from the arc melting, machining, and forging of thorium.

Jan 1, 1962