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By G. Sedelnikova, D. Kim, N. Ibragimova

"The object of this study was three samples of sulfide old tailings, which were obtained after Cu- Zn ores processing. Fine metal dissemination in sulfides as well as fine mineral intergrowth determine the refractory nature of material and low metal extraction using simple methods: gravitation 1-6%, flotation 32-48%, cyanidation 10-37%, and cause the need to use sulfide bio-oxidation to liberate gold and to recover it by heap leaching. The gold is the main valuable metal in the tailings with content 1-1.5 g/t. Heap bio-oxidation with mesophilic and moderately thermophilic bacteria was used for pre-treatment of tailings before gold heap leaching from bio-oxidation solid residues. The tailings have a low permeability < 0.3-1.2 m/day, which is caused by migration of fine particles, decreases recovery rates, and is poorly suited to heap bacterial leaching. Therefore, preliminary gold sulfide tailings with permeability < 0.3 m/day were pelletized using copper containing flotation tailings of converter slags and calcium oxide. The most gold extraction was obtained for pelletized tailings. The base metals (copper and zinc) were precipitated from bacterial solutions. Experiments have demonstrated effective bio-oxidation of all third gold sulfide tailings samples and enough high gold extraction 60-82%.INTRODUCTIONIn Russia, as everywhere, there is a trend toward deterioration in the quality of mineral resources, including non-ferrous and precious metals, manifested in lower grade and higher complexity of ores. The proportion of refractory ores is increasing, characterized by fine dissemination of metals in sulfides, intergrowth, and poor liberation of minerals during concentration, resulting in loss of base and precious metals to flotation tailings.Over the operation period, huge reserves (hundreds of million tons) of ore processing waste have been accumulated at mining and concentration operations. Because of the imperfections of the previously used ore concentration technologies, the content of precious and base metals in flotation tailings is comparable with the grades of the ores being currently processed. Therefore, old tailings can be viewed as an additional reserve of non-ferrous and precious metals. The works (DEN, 1997; Lyman, Johnson, & Guerney, 2000) demonstrate that, tailings containing sulfides (sulfur, copper, zinc, and other metals) are a potential environmental hazard since they produce acid drainage water containing toxic components. Processing those tailings would require designing an effective technology for recovering useful components and protecting the environment."

Jan 1, 2016

By Robert B. Parsons

"New Brunswick Finance Minister John Baxter pulled something out of a hat for the mining industry in April, but there is a general concensus in the industry that he should put II back where it came from.The industry has never been in the mood f or progressive rate structures, but that is exactly what New Brunswick &apos;s 1984 budget offers to this depressed sector of the economy.IntroductionThe Province of New Brunswick stunned the Canadian mining community in April with the announcement that the province&apos; s 16% mining tax rate would be replaced with a progressive rate structure effective January 1, 1984 (Table I). The proposed change, contained in the bud get papers tabled by Finance Minister John Baxter on April 17, caught the industry totally by surprise. The move to a progressive rate structure was completely unexpected for a variety of reasons:• Generally speaking, relations between the province and the industry have been relatively good, yet the industry was apparently not consulted with respect to the proposed measure and had no indication that a change of th is nature was coming. This is in stark contrast to the mood which prevailed during the major revamping of the province&apos; s mining tax regime in 1977: at that time, the industry was invited to contribute in advance to the province&apos;s plan for a new tax structure.• The new structure would appear to make th e province less competitive in terms of mining tax rates with Ontario , Quebec, and other provinces, despite indications in the past that New Brunswick is very cognizant of this competitive factor in formulating mineral policy.• A joint report in November 1978 by federal and provincial officials to federal and provincial finance and resource ministers, which was careful not to directly criticize Ontario and Quebec&apos;s progressive mining tax rate structures, recommended that provincial "" tax regimes be examined to ensure the inclusion of appropriate mechanisms to avoid the excessive taxation of cyclical type profit "" , and that ""the federal and provincial governments consider the concern over progressive tax regimes expressed by the industry and examine mining and royalty tax regimes and the income tax regime with a view to alleviating the effect of such regime on the aggregate marginal tax rate"". In this context, any move to a progressive rate structure would be viewed by many observers as retrograde."

Jan 1, 1984

By Walter Curlook

"With Inco recording record profits over the past year, most people have forgotten the painful years of the last recession/depression when Inco was losing up to a million dollars a day for a short period . While high nickel prices have contributed to the exceptional recent profits, the real achievements stem from the tremendous advances in productivity and cost improvements that make Inco one of the lowest cost nickel producers.Some of the major advances in productivity have occurred in the mines. The establishment of Mining Research Departments in both Thompson and Copper Cliff in 1979/80 provided the stimulus and the opportunity to dedicate personnel to specific research projects, on a full-time basis; and more particularly to concentrate on the efficiency of the total mine system. The Copper Cliff North Mine was brought back into production as a research mine dedicated to the development and testing of new mining methods and equipment. A shop facility known as the ""Murray Shop"" was set up as the centre of innovation for the development and construction of prototype equipment required for new bulk mining methods. While other expenditures were being curtailed , investment in mining research was being increased. An early success was an ""in the hole"" drill that could be broken down into small components to access even the remotest sectors of a mine to convert labour intensive undercut-and-fill mining to "" vertical crater retreat "" , VCR, bulk mining. A new mine manufacturing company-Continuous Mining Systems-was incorporated with the objective of building innovative mining equipment, with strong focus on automated continuous sytems. Continuous Mining Systems has now grown to a $25 million per year business. With these synergistic thrusts, the VCR bulk mining method was implemented in all of the Ontario Division mines, raising the percentage of ore mined by bulk mining techniques from 320/0 in 1981 to over 90% today. Coupled with re-designed job responsibilities, sup- ported by appropriate training, mine productivity more than doubled. It was discovered that VCR mining could be adapted to the narrower Thompson mine ores with identical improvements in productivity. Development of the Thompson Open Pit North had an additional favourable impact on production cost s in Thompson. The timing of the open pit development could not have been better. It permitted Inco to rapidly increase production at high productivity and low cost, in years of record demand and prices."

Jan 1, 1990

By A. Mular, T. Bond, G. D. Farnell, J. F. Kingston

"ABSTRACT:-A 60—cm semiautogenous grinding-(SAG) mill was designed -for continuous wet operation in closed circuit with a vibrating screen. The circuit is fully instrumented and automated. Part of the control system incorporates Foxboro SPEC 200 controllers around the pump box to maintain level. The rest of the control system involves an ACTION model BC2 basic direct digital controller that handles all other inputs/outputs and contact closure sensing:·The success of the control system is attributed to the uniqueness of specially designed mass flow metering systems. Various control strategies are possible. Employed to date has been control of a mill load set-point by cascading the deviation from load set-point as the set-point to the fresh feed rate ""controller"". Mill feed water is ratioed to total flow rate of solids fed to the mill. The performance of the circuit is being correlated with the performance of full scale SAG circuits in British Columbia to develop models, to assess the feasibility of scale up and to investigate the effects of design variables on responses such as circuit throughput. 1 INTRODUCTIONWhere ore types are appropriate, semiautogenous grinding and/or autogenous grinding (AG) has replaced conventional grinding. Secondary/Tertiary crushing plants are thereby eliminated so that capital expenditures are less and overall comminution costs can be lower (Barratt 1982). To establish the suitability of an ore for SAG circuits, pilot scale tests with 1.7 to 1.8 M diameter mills are often conducted. At least one test per ore type in a deposit has been necessary. Often, each test involves a large amount (up to 50 tonne) of sample, so that the testwork can be expensive and may discourage the use of SAG or AG circuits. However, MacPherson (1977) has employed a continuous 45 cm dry Aerofall mill circuit closed with screens and an air classifier to determine whether ores are suitable for SAG milling. The amount of sample per ore type is of the order of 60 kg or less. Thus an established SAG mill scale up procedure that employs small circuits is highly desirable.The purpose of this paper is to describe a small 60 cm wet continuous SAG/ AG mill pilot circuit assembled at the University of British Columbia to study the feasibility of scale up, to assess the influence of design variables, to develop mathematical models and to evaluate the effects of alternative control strategies on circuit performance"

Jan 1, 1988

By A. Roca, V. A. Quezada, O. A. Benavente, M. Cruells

The leaching pretreatment of copper ores is widely used in the Chilean mining industry. Agglomeration and acid curing have been identified as the most useful pretreatments. Of these, acid curing was recognized as beneficial in the dissolution of copper minerals, even in sulphides such as chalcopyrite. Extensive acid curing times have an impact on copper extraction, generate a homogeneous acid distribution in the mineral bed and benefit the inhibition of aluminum-silicate minerals (acid consumers). This document describes some of the theoretical background and results regarding the effect of acid curing in a chalcopyrite sample with 74% purity according to Qemscan analysis and a 28.5% of total copper. Leaching tests are carried out at 25, 50 and 70°C, evaluating the effect of a pretreatment on the chalcopyrite dissolution. The original sample and products generated were characterized by X-ray diffraction analysis and Scanning Electron Microscopy (SEM). The performed experiments indicate a direct relation between the effect of curing time and temperature in copper extraction. 92% of copper can be extracted in a leaching at 70°C and with 15 days of curing. Elemental sulfur, jarosite and copper polysulfide (CuS2) have been detected in leaching products. INTRODUCTION The copper extraction from minerals is a technique that has been developed for hundreds of years in the world. In 2017, the largest copper producer was Chile, exported 5.5 million tons (COCHILCO, 2018). However, in order to preserve this production level means overcoming multiple challenges. In the case of the Chilean copper deposits, the average copper grade in 2016 was 0.65%, lower than the 1% declared in 2004 (Consejo Minero, 2018). This is mainly due to the deeper of the deposits reaching sulfide mineral zones, mainly chalcopyrite. Traditionally, these sulfurized zones ore are treated through concentration by flotation and subsequent pyrometallurgical treatments. However, for some copper companies it is complex to process by this alternative, due to the high costs and high rates of water consumption. The mineral resources of these companies are known as "low-grade sulfides" and do not allow, economically, the treatment of these minerals through concentration by flotation. This is how hydrometallurgy becomes an alternative for the treatment of this type of deposits. In addition, several companies have hydrometallurgical plants, which would allow the operational continuity of these plants.

Jan 1, 2019

By M. K. Walter

"The underground operations of Kidd Creek Mines uses an average of 450 U.S. gpm water during regular operations, and discharges an average of 800 U.S. gpm through consecutive staged pumping lifts of 1200f t.Water is used as a flushing medium for the drilling operations and as a dust suppressant for drawpoint mucking. The water retains an average of 5% suspended solids by weight which is removed underground before being pumped to the surface. This paper outlines the treatment of the mine water for the removal of suspended solids which are chemically treated to settle out as a sludge product of 60% solids by weight. This process reduces the sludge handling operation by 50%. The sludge is systematically disposed into the ore passes.IntroductionThe Kidd Creek minesite, located 27 km north of Timmins, Ontario, produces 4.5 million tonne s of copper, lead, zinc and silver ores annually from its No. I and No.2 underground mining operations. Both mines use a sublevel blasthole stoping method of extraction.Water from the underground operation passes through a series of surface settling ponds, where it is treated to remove heavy metal ions from solution. A blend of the pond effluent with fresh water from Kidd Creek, supply the underground with water at an average rate of 450 U.S. gpm. Water flows from the production zones through coarse sumps and into a main pumping station. There are five main pumping stations underground, three in No. I Mine and two in the No.2 Mine.The No. 2 Mine pumping stations are located on the 4800 level and the 3600 level. All water below the 3600 level to the shaft bottom is controlled from the 4800 pumping station. The water from the 4800 pumping section is combined with water from the remaining levels of the No.2 Mine at the 3600 pumping station. Water from the 3600 pumping station is pumped to the 2400 pumping station in No. I Mine.The No. I Mine pumping stations are located on 2800, 2400, and 1200 levels. All water below the 2400 level to the shaft bottom is controlled through the 2800 pumping station. This water is pumped to the 2400 pumping station. The 2400 pumping station also controls the water below 1600level to 2400 level."

Jan 1, 1988

By R. J. Mitchell

"High narrow backfills of significant strike length approach the stress conditions associated with a free standing wall but this lower bound design approach is not considered efficient for earth structures. This paper considers the design of high narrow backfills using upper bound limit analysis, retaining wall theory with backfill arching and centrifuge model tests. Complex toe support situations pertaining to operational factors at Falconbridge&apos;s Lockerby Mine are investigated. It is shown that the susceptibility of high narrow fills to toppling is much lower than anticipated from the retaining wall analysis and that toppling can be avoided by a suitable toe support. It is also concluded that adhesion between the fill and an adjacent pillar can markedly increase the stability of the fill. INTRODUCTIONFalconbridge&apos;s Lockerby Mine pillar projects will expose cemented tailings backfills to heights (H) up to 55 m. The exposed backfills may have strike lengths (L) greater than the heights but are relatively narrow, having widths (w) of up to 12 m. The bulk cement content of the fills varies from 8.3% (12.1 T:C) to 3.0% (33.1 T:C). Exposed faces may have up to a metre of overhang due to stope overblasting, as shown in Figure 1. These fills have a solids specific gravity of close to 3.0 and were placed at a pulp density of about 68%. The tailings have a fairly uniform grain size with 32% less than 0.075 mm (200 sieve) and about 12% slimes (less than 0.02 mm sizes). The fill exposed by early pillar removal will be backed by adjacent, near vertical, ore pillars. Future pillar removal may expose similar fills which are not supported by an adjacent ore pillar but which will be backed by either an open void or by uncemented backfill. Furthermore, these fills may be undercut when the pillar slot is driven, further reducing stability (case 3, Fig. I) or a wedge could be left to help support the fill (case 2, Fig . 1). This paper presents limit equilibrium analyses for these various backfill conditions in a 22: 1 T:C fill and com- pares the results to data from centrifuge model studies at a scale factor of A= 157 as indicated in Figure I. Prototype fills have a 6 m deep cone plug of 16:1 T:C which is accounted for in the comparison of centrifuge model test with analytical results."

Jan 1, 1989

By Eric D. Jamieson

"How well is the Canadian coal industry able to expand in the tough competition with other fuels in Canada and with other suppliers in the international, metallurgical and thermal coal trade? Coal production as a whole decreased between 1950and 1960 and, although there has been a tripling of production since then, underground production continued to decrease until 1975. This trend has been reversed to a certain extent as a result of the modernization of mines in Cape Breton, but in 1978 over 85% of coal production came from surface mining.Against this background, the paper reviews current Canadian mining operations as described in papers presented at the 1979 CIM Annual General Meeting. Conclusions are then drawn regarding some of the longer-term mining applications in relation to the latest coal demand forecast, which indicates a potential Canadian production requirement of 160 million tonnes per year by 2000. IntroductionThe Canadian &apos;coal industry is experiencing a period of expansion and a new record for production is set with each passing year. This growth pattern over the last IS years has been based on two main markets-the generation of electricity in Canada and the export of coking coal to Japan. Supply to those markets has entailed either the development of mining, coal preparation and transportation systems for the delivery of large volumes of products with predetermined specifications or the establishment of minesite plants designed specifically to suit the characteristics of the coal in the adjacent deposits (Fig. I).Coal is a low-value commodity in relation to its bulk, and the economics of coal use become progressively less attractive with increasing distance from the producing mine. The transportation component in the export trade and in the movement of western coal to Ontario is a major cost factor. In the latter case, it approaches the cost of coal produced at the mine. In addition, the .international competition among coking coal producers chasing diminishing markets in a worldwide steel recession as well as the competition from U.S. coals and other fuel s for Canadian thermal coal have introduced a tight set of parameters to govern mining practices in all parts of the country. Some appreciation of the required changes in mining techniques brought about by declining traditional markets and the rigorous demands of the new bulk markets can be gained by comparing production from surface and underground mines over the past 25 years (Fig . 2)."

Jan 1, 1980

By Mary Kama, Kaul Gena

"Magnetic skarn ore (MSO) is one of the major copper bearing ore extracted by the Ok Tedi Copper Mine in Papua New Guinea. Copper minerals are recovered by flotation while the iron not associated with copper are discarded as tailings. The objective of this investigation was to determine the iron ore reduction kinetics for the Ok Tedi MSO and ascertain if it can be processed to produce sponge iron for a mini steel plant in Papua New Guinea.SEM-EDAX analyses of the Ok Tedi MSO indicated 10.1% C, 30% O, 0.6% Mg, 1.1% Si, 21.1% S, 0.8% Ca and 36.2% Fe. Most of the iron is in sulfide form. Both naturally occurring and roasted sinters of Ok Tedi MSO samples of different particle sizes were reduced by charcoal carbon at three different temperatures and seven different reduction times. Analyses of the reduced products indicated a metallic iron content of more than 65 wt.% on average.Results showed that there was no significant difference in reduction between fluxed and control materials. Only a slight increase in kinetics with reduced particle size, hence the reaction rate constant (K) did not vary much within the temperatures investigated. Reaction kinetics increases with increasing reduction time at 900°C. Therefore, more iron reduction is observed with particles of 106 µm size. In addition, the results also confirmed that the reduction energy used was higher at 800°C and lower at 1,000°C. In summary, iron reduction can be improved but close monitoring of temperature and reduction times are essential to determine the reaction kinetics of the Ok Tedi MSO. INTRODUCTIONMost mines in Papua New Guinea mine large quantities of iron in the form of sulfides, carbonates, oxides and sulfates that are eventually disposed off as tailings. The Ok Tedi magnetic skarn ore (MSO) contains a significant amount of hematite, magnetite, siderite, ilmenite and pyrite that can be a source of iron. The mineralogical compositions of Ok Tedi MSO reveals more iron minerals than copper, yet all iron containing minerals are collected in the tails from the main copper production stream. Therefore, this study is conducted to investigate the possibility of producing direct reduced iron (DRI), or sponge iron, from the MSO. Such sponge iron may serve as the feedstock for electric arc/induction furnace based mini steel plants in Papua New Guinea."

Jan 1, 2016

By Gerardo Fuentes

Arsenic extraction from Chilean copper concentrates up to nearly 99% was achieved, using hydrothermal reactions. Arsenic appears in nature in more than 200 mineral species, being arsenopyrite (FeAsS), enargite (Cu3AsS4), and tennantite (Cu12As4S13) the most common species. In addition, arsenic is present in a large amount of copper concentrates, produced in northern Chile. Medical statistics show that in northern Chile, the amount of cancer to the lung, skin and bladder are the highest in the country. The latter situation, demonstrates the importance of studying metallurgical processes that do not generate atmospheric pollution. The hydrometallurgical processes such as hydrothermal treatment in autoclave reactors, do not produce gaseous emissions. On the other hand, the arsenic remains in solution from where it can be transformed in scorodite by widely known methods. Previous works about hydrothermal treatment of enargite have shown the feasibility of transforming the enargite of the copper concentrates into chalcocite or mineral species of the chalcocite family such as djurleite, digenite and for this reason enrich the concentrate in copper and pass the arsenic to solution. For this research, two Chilean copper concentrates were used, concentrate 1 with 5.5% arsenic and concentrate 3 with 1.8% arsenic. These concentrates were subjected to a complete chemical and mineralogical characterization. Later these concentrates were carry out to batch tests of hydrothermal treatment. Also, these concentrates were subjected to grinding to have different particle sizes. For the hydrothermal tests, a liter capacity Autoclave Engineer reactor was used. Characteristic of this reactor was the maximum temperature 350°C, 5000 PSI pressure, and 900 rpm agitation speed. Kinetic tests were carried out with the two concentrates maintaining the same solid: liquid relationship, the same agitation velocity and the variables studied were treatment temperature, time of reaction, concentration of copper in the solution and grain size of the concentrates. The conclusions of the study indicated arsenic extraction of the order of 93.98% from the concentrate 1 and arsenic extraction of the order of 98.74% from concentrate 3. After the hydrothermal treatment, the solids and solutions were characterized chemically, by electron microscopy and X ray diffraction. Also the solids were characterized by grainsize through a particle size analyzer (MICROTRAC). Results of batch treatment shows that arsenic can be release almost completely from real copper concentrates using this hydrothermal process and the next stage will be a scale up process in order obtain results for pilot plant design. INTRODUCTION Arsenic is an impurity that appears associated with copper minerals forming enargite, tennantite, tetrahedrite, and that due to the pyrometallurgical treatment either in conversion or roasting furnaces, it goes into the atmosphere together with the sulfur dioxide. A great quantity of literature can be found to eliminate arsenic or try to separate arsenic from copper. The methods used are mainly leaching processes with or without pressure (Padilla, Jerez & Ruiz, 2015) with different reagents like chloride media (Herreros, Fuentes, Quiroz & Viñals, 2003) or chloride media with sulphuric acid (Riveros & Dutrizac, 2008) or sodium hypochlorite (Mihajlovic, Strbac, Zivkovic, Kovacevic & Stehernik, 2007). It is known too that Chile is the first copper producer in the world and a great quantity of its minerals are in the north of the country, in Antofagasta.

Jan 1, 2019

By Aleksandar N. Nikoloski, Tendekayi Tapera, Glen P. O’Malley

Chalcopyrite (CuFeS2) and enargite (Cu3AsS4) are among the most important copper sulfides. At present, many known deposits of these minerals are uneconomic to process because they are of too low grade, insufficient size or too remote to be cost effectively treated with conventional technologies that can deal with their refractory nature. Therefore, developing an effective, low cost extraction process for recovery of copper from them is important. The research presented in this paper will deal with potentially cost effective strategies involving catalysed processing, studied under conditions relevant to recycle heap leach conditions. The present account summarises some of the main findings from the research program carried out at Murdoch University between 2014 and 2018 that has investigated the effects of the common leaching parameters, major and minor species present in the leach system and additives on the rate and extent of copper extraction from low-grade ores, in which primary copper sulfide minerals such as chalcopyrite and enargite were the dominant copper minerals. The study involved batch leaching tests, detailed structural and mineralogical characterisation and thermochemical modelling under conditions relevant to heap leaching. The results have demonstrated that silver in particular has a strong catalysing effect on the extraction of copper from ore under the leach recycle conditions and, at an adequate dosage, can effectively overcome surface passivation, enabling almost complete extraction of copper from chalcopyrite as well as enargite. The aim of this paper is to present the effect of the studied additives and to briefly elaborate on the mechanism of the silver catalysed leaching process. In addition, the presence of certain secondary agents was shown to lower the critical dosage of silver and promote extraction. The data from the study allowed the development of a theory for the silver catalysed reaction mechanism, which enables further optimisation and cost-effective application of this strategy in practice. INTRODUCTION Researching the extraction of copper from chalcopyrite is important as it is the most abundant copper mineral in the earth’s crust. The majority of ores containing this mineral are processed by flotation to produce a concentrate, followed by smelting and electrorefining. However, most reserves available nowadays are of low grade or limited in size, and therefore not suitable for this conventional approach. Hydrometallurgical processing via heap leaching with or without the aid of bacteria has been shown to be potentially economical. Chalcopyrite is refractory though and suffers from slow leaching kinetics and poor overall extraction, so understanding the mechanism of how it leaches has received significant attention by researchers working in this field over the past 50 years. The refractoriness, which is the main issue with the hydrometallurgical approach, is generally described as passivation of the chalcopyrite surface whereby a surface coating is formed that blocks the reaction interface or wetting of the chalcopyrite, limiting the copper extraction. Exactly what this layer is made of or how the issue could be overcome has been the subject of intense study and debate for many years. One of the limitations of the work to date is that much of the research focus has been on typical initial leaching conditions, while there has been relatively little research into how the leaching is affected under recycle solution conditions where certain metal ions (Fe, Mg, Al) have often accumulated in the liquor. This occurs because the leach solution exiting a heap contains many species from the dissolution of gangue minerals and typically this solution is returned to irrigate the heap, once the copper has been removed, leading to an accumulation of these species.

Jan 1, 2019

By G. R. Davidge

"Falconbridge Mine has a history of significant microseismic activity dating back to 1955. Since mid-1981, a microseismic monitoring system has been operating in the area around the No .9 Shaft hoist room located 25 m from the are zone at a depth of 1200m. Several mine wide faults dissect this area and have been shown to be microseismic-active due to mining. The microseismic monitor has been interfaced with a small dedicated personal computer and a communications device to perform routine data evaluation and to produce graphical output. The programs are described and selected result s from the monitoring program are presented.IntroductionFalconbridge Mine is located on the southeast rim of the Sudbury Basin. The nickel-copper sulphide ore zone is essentially a tabular orebody striking approximately east-west and dipping at 80 degrees north near surface and rolling to 75 degrees to 80 degree s south by the 1000 level. (Mine level number s represent the approximate depth in feet below ground surface .) This dip is maintained down to the 6000 level. The north wall is comprised of jointed norite and a faulted contact up to 1 m thick exists between the ore zone and the norite. The south wall rock is a greenstone with highly siliceous lenses and often has a faulted contact with the ore zone. No less than five mine wide faults exist, as shown in Fig. I.Mining ha s been carried out from virtually the bedrock contact to depths of 1830 m although the majority of current activity is between 900 and 1500 m below surface. A winze provides access below the 4025 level and the cage hoist room is located on the 3850 level in the north wall 25 m from the contact. Because of concern for the stability of this hoist room, there has been no mining activity within 60 m of the hoist room and by 1980 this block of ore was one of the major blocks of high-grade ore remaining in the mine . Mining of this block was originally scheduled for very late in the decade.Prior to a six-month shutdown in 1982, this mine produced approximately 450,000 tonnes of ore annually, mainly by cut and- fill techniques. Following the shutdown, annual production has been reduced to approximately 200,000 tonnes and production is now mainly by undercut and fill techniques .Mining-induced seismicity has occurred at Falconbridge Mine since at least 1955 and reviews of the microseismic problems for the periods from 1965 - 1970 and from 1971 to 1979 were made by Singh (1971) and Vongpaisal et al. (1980), respectively. The need for instrumentation was addressed by these authors. Following several large events during the spring of 1980, a decision was made to investigate existing microseismic monitors and to apply micro seismic monitoring techniques in Falconbridge Mine. Application of microseismic monitoring to Falconbridge Mine was to concentrate on the No . 9 Shaft hoist room area of the mine, particularly around the 4025 level where a large mechanized cut-and- fill stope was approaching this level. By mid - 1981, the microseismic monitor was fully installed and with in a year , a short-period seismograph and a personal computer had been added to the system."

Jan 1, 1984

By Akihiko Nishiyama

Unmanned construction technology used for remote control operation of construction machines has some problems to solve compared with manned operation of construction machines, such as fatigue due to long-term operation or decreases in operational efficiency. To solve these problems, we recorded the viewpoints of operators in both manned and remote control operation and analyzed the differences. This paper reports on our discussion of improving the operability of remote control operation based on the analysis results.

Aug 1, 2013

By Anthony P. Makuch

Dynatec Corporation is an integrated mining services company, providing mine development, operations management, engineering, drilling and metallurgical services to the North American mining industry. Dynatec was the contract operator of the Ken Snyder Mine in Midas, Nevada from start of production in January 1999 to September 2001. This paper summarizes Dynatec?s experience and approach to the use of longhole stoping methods for mining to widths of 1.3 to 2 metres in a steeply dipping narrow vein orebody.

Oct 1, 2001

By J. P. Messervey

As a result of my field examinations in this Province, I have been struck by the evidence of widespread mineralization in rocks, particularly the limestones of Carboniferous age. Six prospects of lead and zinc or lead alone scattered through the eastern part of the mainland, one copper prospect and three veins of siderite, all point to a period of mineralization subsequent to the forming of the Carboniferous rocks in which they occur. While none of the present prospects are of proved economic importance, still it is possible, and indeed probable, that further prospecting will find concentrations sufficiently large to make mines. It may possibly aid the prospecting for these base metals if the present scraps of information are assembled from various sources, and I will further briefly recount the information as a result of my observations. Gay?s River At Gay&apos;s river, midway between Halifax and Truro, and four miles east of the railway, numerous pits and natural exposures show galena and sphalerite in limestone of Carboniferous age, near where it lies unconformably upon slate and quartzite of the gold series. These exposures extend for a length of over one thousand feet along a curving contact. The pits show that on the contact there is a fossiliferous and somewhat porous layer of limestone, which is so impregnated with galena and small amounts of sphalerite as to be of ore grade. Wherever observed, the thickness of this layer is less than two feet.

Jan 1, 1929

By J. C. Glandus, N. Tessier-Doyen, M. Huger

The Young&apos;s modulus of bi-phased model materials (vitreous matrix containing spherical alumina inclusions) have been determined by two complementary approaches: experimental and analytical. If the matrix and inclusions exhibit close coefficients of thermal expansion, the experimental results lie in the vicinity of the lower bound of the Hashin & Shtrikman&apos;s model. If there is a dilatometric disagreement between the components, untypical behaviors, similar to those obtained for a family of industrial refractory materials, were observed when the temperature varies.

Jan 1, 2004

By S. Perkins, E. Young, L. Dufour, K. McVey, L. Rolandi

This paper presents a review of plant layout considerations incorporated into recent designs of SAG/Ball mill circuits for two medium sized concentrators. The plant layouts presented and the design concepts discussed, relate to smaller SAG circuits, but can equally apply to larger milling circuits. Included are design concepts and ideas introduced by the various project teams, and the focus is on the primary factors of any layout design which are safety, constructability, operability, and capital cost.

Jan 1, 2012

Orebody classification systems ? Modern classification systems ? Genesis and environment of deposition (Important in economic geology) ? Shape and structure / Form, texture and mineral content ? Mining and geomechanics ? Size ? Massive versus tabular Requirements for mining method selection ? Classification of ore deposit ? Shape, size, attitude, continuity ? Grade and distribution, strength and large scale structures present, mineralogy and small scale structure, host rocks ? Classification of mining method ? Method of support (Stress ? strength ratio) ? The method selection ? Geographical and economic factors of the location

Feb 1, 2008

By Werner W. Scholz

A corrosion-resistant lining is, quite often, selected on the merits of its corrosion resistance only. This paper demonstrates the effects of temperature, pressure, weather, design aspects and variances of physical properties within the scope of the generic designation of a corrosion-resistant material or materials. The base for the study is a rubber- and brick-lined steel vessel, with unchanged chemical conditions. Graphs and sketches illustrate the various effects of physical influences on the selected lining specifications.

Jan 1, 1979

By Lesley Hymers

First Nations Natural Resources Youth Employment Program PDAC Mining Matters ? Charitable organization ? Provide education to students, teachers, and the public about rocks, minerals, metals, and mining ? Provide current information and offer exceptional educational resources that meet provincial Earth science and geography curriculum expectations First Nations Natural Resources Youth Employment Program ? Provide instructional development workshops for educators who are teaching Earth science and geography ? Since 1994, reached more than 400,000 students, teachers, industry representatives, and members of the public

May 1, 2009