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By Piotr Malkowski

Studies on the properties of rocks heated to high temperatures are rather rare. Such research is occasionally conducted for example; in areas around nuclear power plants. The national Polish coal gasification (underground coal gasification, or UCG) project has, however, forced the analysis of the geomechanical properties of heated rocks in the vicinity of a designed geo-reactor. Ukrainian experience with UCG show that rocks up to 2 m from the burned coal seam be at a temperature > 600ºC. Such a high temperature will undoubtedly influence their physical properties. This paper presents studies on the strength and deformation properties of carboniferous rocks in the Upper Silesian region, where the UCG process is planned. Three types of rocks were tested: claystones, mudstones and sandstones. Laboratory tests of these rocks evaluated compressive strength, elastic modulus and weight loss. An evaluation of the results of the tests comparing the thermal conductivity of rocks and their specific thermal capacity was then carried out. All of the rocks studied were heated to 300, 600 and 1000ºC, and also evaluated at room temperature. This procedure shed new light upon the behavior of heated rocks in relation to their distance from the designed geo-reactor. The test results presented were developed within Research Task No. 3 ?Developing a technology of coal gasification for efficient production of fuels and electric power?, financed by The National Centre for Research and Development under strategic research and development programme ?Advanced Technologies for Energy Generation.?

Aug 1, 2013

By R. A. Leveille, M. D. Doggett

"Economic returns for the copper industry have been assessed by building cash flow models for each of the 100 new mines brought into production over the past 20 years. Ninety-one of the 100 new mines returned the assumed 8% cost of capital and generated a positive net present value (NPV) at the development decision point. Economic criteria for individual mines are highly variable with NPV ranging from -$111 million (-$111M) to +$3850M (all money values are presented in United States dollars) and internal rate of return (IRR) ranging from -8% to +95%. The copper industry collectively would generate approximately $39 billion dollars in NPV through the development of the 100 new mines.The returns to exploration ($174M per deposit) were measured by deducting the cost of exploration per deposit ($221M) from the returns to development per deposit ($395M). Overall, the copper business has provided positive returns to exploration. However, the variability in returns across deposits means that only 41 of the 100 new mines can carry the average cost of exploration. The long lead times and high costs associated with exploration result in only those deposits with large amounts of contained copper being able to cover the average finding cost of the industry.The returns to development and exploration are shown to be highly sensitive to the cost of capital and metal price assumptions. With respect to deposit type, porphyry deposits are both larger (NPV) and exhibit lower profitability (IRR) than the nonporphyry deposits. On a geographic basis, returns to development and exploration are higher in Chile than elsewhere, reflecting the larger average deposit size and lower average exploration cost per deposit."

Jan 1, 2009

By Marketa D. Evans

The mining industry has a significant opportunity to capitalize on its past learnings in order to build better social relationships. The industry?s relationship with society is both critical and under pressure. Rising levels of public opposition and social conflict are already having material impacts on operations around the world. Industry has an opportunity to shape the future direction of this social engagement, build public trust and proactively respond to a material risk to operations, but first it needs to better understand the nature of the challenges and the urgency of addressing them.

Aug 1, 2013

By Kathy S. Kalenchuk

Damages have been observed in shafts, backfill infrastructure and the slick line at the Leeville Mine. Shaft damage (shearing and spalling of the concrete liner) is attributed to mine-induced rock mass deformations concentrated where regional faults intersect the shafts. Aggregate bin, mixer station and conveyor drive damage (shotcrete shearing, heave of concrete floor slabs and bending of a vertical steel beams) is attributed to rock mass squeezing induced by elevated magnitudes of the vertically orientated major principal stresses. Separation of the slick line has occurred do to extension of the stressshadowed rock mass immediately above the mined out areas. Three-dimensional numerical models have been developed and calibrated to simulated rock mass deformations with magnitudes similar to those believed to have produced the observed damages. By stepping through the mine sequence, models reproduce deformations at the same mining stage as when damage has occurred. Calibrated models have been used to forward project further damage over the remaining mine life.

Jun 1, 2012

MR. J. F. MYERS, Consulting J3eneficiation Engineer, Greenwich, Conn.: In the written discussion contributed by Mr. F. C. Bond in item ( 2) (page 515), speaiking about the significance of the ratio of mill diameter to the make-up ball diameter, he states: "When this ratio exceeds 100 the power and capacity of the mill are de-creased"; and the paragraph ends with a reference to the 30 per cent ball volume "with some de-crease in mill capacity". I believe this broad statement is incorrect. When we are dealing with a non-cataracting mill, pre-ceded by a good rod mill, there is a slight increase in capacity, but the power does drop. The second point that I consider needs consideration is Mr. Bond's item (8), Proper Mill Speed (page 516). This paragraph should be qualified to cover single-stage mills only. It does not apply where a rod mill is followed by a non-cataracting ball mill. The statement as is, with no qualification, gives an erroneous idea of proper mill speeds.

Jan 1, 1957

By Balmer Neilly

Early in my term of office it was announced that my Presidential Address would make particular reference to the subject of Mine Taxation in Canada. With this purpose in view there was drafted a Balance Sheet and Earnings' Statement of a Gold Mining Company. This in turn was submitted to the Dominion Income Tax Authorities in Ottawa and to the Minister of. Mines of each of the several Provinces of Canada. The response to the invitation was not as complete as we had hoped it would be, but the figures that were obtained will be presented during the present meeting, and they constitute, I hope, a sufficient basis for extended study and additional enquiry during the year to come ( 1) . In the form letter that accompanied our request to have the submitted earnings assessed, I made the following assertion: "In this work we have three objects in mind. 1.--We will get direct comparison between the different Provinces in Canada. 2.-We will in this way educate our members concerning taxation as it affects the mining industry. 3.-We will publish the details as to how the assessment is calculated by each body, so that a Mine Manager in the most remote district will have a ready reference to guide him in his annual return to the taxing bodies. As things stand, there is no intention of making this a basis for a critical attack on the present rates assessed. It is intended as an authoritative summary of actual conditions as they presently exist".

Jan 1, 1934

By Masatsugu Morimitsu

This paper introduces new technology of oxygen evolution anodes which can be applied to produce copper, zinc, cobalt, and other metals by electrowinning. The anode consists of nano iridium oxide particles dispersed in amorphous tantalum oxide matrix as a catalytic layer formed on a titanium substrate. The anode can reduce oxygen evolution potential by 0.25 to 0.55 V compared to commercially available lead alloy anodes and can suppress unwanted side reactions such as manganese oxyhydroxide, lead oxide, cobalt oxyhydroxide which occur during oxygen evolution in the electrowinning solutions. This technology is effective for environmentally friendly electrowinning processes with low energy consumption and less anodic deposition.

Jan 1, 2011

By G. W. Toop

"The Cominco smeller in Trail, British Columbia, is a large integrated lead-zinc production facility. In the plant description, emphasis is given to the pyrometallurgical operations including zinc concentrate roasting, lead singer-blast furnace processing and silver refining. Production figures for the main metal products - zinc, lead, silver and gold - are provided.IntroductionIncorporated in 1906, Cominco Ltd. is an integrated natural resource company with principal activities in mining, smelting and refining, mineral exploration, fertilizer production and electrical power generation.Cominco is one of the world's largest producers of zinc and lead, accoW1ting for about 10070 of mine production in the western world. The company also produces and sells copper concentrate, copper sulphate, copper arsenate, sodium antirnonate, silver, gold, cadmium, bismuth, indium, and germanium dioxide and a range of fertilizers and sulphur products.Zinc OperationsRoastingThe roasters currently treat about 1400 t/d of zinc concentrates. Over half of the total concentrate treated originates from the Red Dog Mine in Alaska. During the summer, concentrate is shipped from Alaska to Vancouver where it is loaded into rail cars and hauled inland, transferred to trucks and delivered to Trail. The remainder of the roaster feed is made up of Sullivan concentrate and various custom concentrates. These arrive either by train or by truck.There are three roasters available for roasting the concentrate. The two major roasters are Lurgi fluid bed units. Each Lurgi roaster can process concentrate at about 1:7 tonnes per hour (tlb). A smaller Cominco suspension roaster with a capacity of 10 tlb is also used. The flowsheet for the high temperature section of the fluid bed circuit is shown in Figure 1.Concentrates fed to fluid bed roasting are conditioned with 7 1/min water to give 8% moisture in feed. Two slinger belts throw the mixture into the fluidized bed. The fluid bed roasters are 10.4 m in diameter with a bed depth of 1 m. Grate area is 84 m2• Normal operating conditions include bed temperatures of 930°C to 950°C, fluidizing air at 750 Nm3/min and a wind box pressure of 2000 mm H2O."

Jan 1, 1994

By Enrique I. Acuña

Creighton Mine is part of the mining history of Sudbury with more than 100 years of operation. Currently the deeper levels of the mine are reaching the 8000 ft level without implementation of mechanical refrigeration system as a result of the use of the Natural Heat Exchange Area (NHEA) over the past decades. The NHEA of Creighton Mine is part of an old block caving area divided into 4 blocks of trenches that were used to extract the ore. Currently, it is used year round to condition the outside temperature before the airflow enters the fresh air system of the mine. As the mine is progressing deeper, underground temperatures in the lower levels are starting to approach the limit of Vale?s guidelines for working in heat. This paper presents the study developed to improve the management of the NHEA to obtain cooler temperatures at the intake of the ventilation system and outlines the impact to the mine in terms of the additional level(s) that could be operated underground without the use of mechanical refrigeration. This is another of the efforts currently under development for energy conservation and to reduce the capital and operational costs of Creighton Mine while extending the expected life of the mine.

Oct 1, 2010

By Clyde Williams

If you would allow me some liberties, I would re-state the title of this talk as Scientific Research, Our Greatest Resource, because that title would represent more clearly a present-day conception of the metals and minerals situation. It is a subject worthy of careful consideration. Canada and the United States are so similar and interdependent in their national economies that, in the following discussion, examples of conditions in the United States may? be interpreted to apply to Canada as well. Moreover, it is a striking fact that the per capita value of mineral production in Canada and the United States in 1940 was almost the same. Therefore, in the consideration of this subject, I have made no attempt to differentiate between the two countries. The consumption of the world's mineral resources in the last few decades, and particularly during World War II, has been so enormous as to require some form of magic to ensure the continued progress of civilization in the face of a diminishing supply of these resources which are so critically essential. As Dr. C. K. Leith pointed out in 1941, industrial expansion has been so great that, during the first forty years of this century, the world used more of its mineral recourses than in all preceding history. And this did not include the all-out consumption during the succeeding five years of war.

Jan 1, 1947

By A. G. Slade

"This paper deals with the direct application of rock mechanics in the underground mines at the Sudbury Operations of Falconbridge Nickel Mines Ltd. It covers mining methods, the use of photoelastic models, the fore-casting of rock strains and their elimination, closure methods and other common methods of ground control.INTRODUCTIONROCK MECHANICS IS A STUDY IN ROCK BEHAVIOUR and, although it is being termed a new science, it has been practiced since the industry began. Every person involved with rock excavations, from the mine superintendent to the stope driller, is actually practising rock mechanics. They probably call it by another name -experience, and applications of this knowledge are in evidence throughout the Falconbridge operations. Only in recent years have formal rock mechanics studies been employed to provide technical assistance to the mine operators in their primary objective of producing ore safely."

Jan 1, 1968

By G. A. Vissac

IN THE preliminary design of a coal washery, the most important factor to evaluate is the ash content of the final product. The ash content permissible may be imposed by market demands, but, in the final analysis, sooner or later - as most consumers today are buying coal on a 'heat value' basis - the coal operator has a certain margin of latitude. and the ash content of the coal to be delivered can be determined on the basis of maximum returns and highest profits. A few years ago, the most desirable separation was selected on the basis of the plus-minus 0.10; that is, the most desirable gravity of the separation was selected at the point showing a minimum amount of near gravities in the raw coal. The reason for this was an expected wide error over these near gravities. Today with the recent development of cry accurate, automatically controlled cleaning apparatus, a much larger latitude is possible, and the most desirable gravity of separation can be selected, almost exclusively, on the basis of the economic factors involved. To illustrate these new methods of investigation we shall give two examples, based on actual coals from the western United States.

Jan 1, 1957

By C. G. Williams

This paper describes the planning, development and operation of the Highvale Mine to supply coal to both the existing Sundance and the approved Keephills thermal power plants of Calgary Power Ltd. Reference is also made to the company 's Whitewood Mine, which feeds the Wabamun thermal plant .

Jan 1, 1979

By E. Henderson, L. K. Daneshmend

Drawpoint control is critical in determining the cutoff point for load-haul-dump mucking operations to minimize dilution. It is also necessary to ensure even mucking distribution and to prevent possible hang-up of material within a stope. A prototype production monitoring and reporting system has been developed for load-haul-dump operations in under-ground mines. The system generates accurate and timely information regarding mucked tonnages and drawpoint and ore/waste pass utilization. The monitoring system integrates a PLC-based load weighing system with a radio frequency identification (RFID) system for locating the vehicle. The system records the identification and time of entry and exit of each draw-point and ore/waste pass visited during a shift, as well as the weight of each bucket load. A trial of the system was conducted at the CAN-MET Experimental Mine near Val d’Or, Quebec. The monitoring and reporting system functioned as designed, with the exception that the maximum read range of the RFID tags under dynamic conditions was found to be a limitation. RFID systems with greater range capabilities have been identified for a second generation system. The system is the first of its type in North America to demonstrate that RFID tagscan be successfully applied to locate trackless underground equipment. Because of their ability to locate equipment and personnel within underground mines, RFID systems should be considered a key technology for future mine information and process control systems.

Jan 1, 1996

By V. Murugaiyan

The Geotechnical Engineer is faced to view problems emerging from the task of protecting the environment and also the problems related to prevention of natural hazarders. Geo-Environmental Engineering, based on the development of geotechnical engineering, addresses the problems for the industrial world and the impact on health and welfare in relation to pollution of the ground. In the recent years, acute land pollution due to indiscriminate discharge of industrial effluents especially Organic acid based effluents has become one of the major concern due to erosion in the privatization of sustainable development under Indian Scenario. To study the effect of chemical changes on soil properties due to amino acid effluent contamination on soil and erosion behavoiur. The changes in the soil properties of effluent contaminated clay and silty soil were experimentally observed to be due to the interaction of organic and inorganic constituents of effluent on index properties of soil. The surface reactivity of soil mass is experimentally reported to be varying proportionately with respect to clay (%) in the soil. Also higher surface reactivity of clay increases the Solid Retension Time (SRT) with increase in rate of chemical transformation of organic and inorganic solids within soil. Hence soil S1 (high clay content 54.5%) showed increased SRT and soil S3 (low clay content, high silt and clay content 94.9%) showed decreased SRT and long transformation stage.

May 1, 2004

By J. A. McCamley

Gypsum scrap generated from wallboard manufacturing, construction and deconstruction activities in North America, Europe and Japan is a recognized environmental problem. Landfill disposal of this gypsum scrap is problematic, with deposits often creating hydrogen sulphide emissions and metallic sulphide groundwater leachates. Of these regions, Europe is the most advanced in dealing with the issue having enacted legislation, which will come into effect in July 2005 that will strongly encourage gypsum recycling throughout the EU. An estimated 10% to 17% of all gypsum used in the wallboard industry becomes recyclable scrap, which represents approximately 1% of the total waste stream in North America. In the United States, 2.5 to 4.5 Mt of gypsum scrap is generated each year; the volume is similar in Europe (the percentage of total tonnage is less because of the higher use of brick and concrete). The Greater Vancouver region of British Columbia has banned gypsum from its landfills, and as a result, all gypsum scrap is now recycled. New West Gypsum Recycling, a Canadian firm, uses its proprietary technology to process large quantities of gypsum scrap that is reincorporated into new wallboard, at percentages ranging up to 25%. The operation of New West Gypsum Recycling Inc. of Langley, Vancouver is examined as a case study and recommendations are provided as to how other urban regions can implement similar gypsum scrap recycling programs.

Jan 1, 2004

By Jeonghwan Kim

Intelligent Excavation System (IES) has been considered to be one of the desirable solutions to improve the productivity, quality and safety of the current earthwork processes. IES is composed of various hardware and software modules including task planner (work command generator), local and global work environment sensors, GPS and other sensors to acquire the excavator?s status, robotic controller and electronic valves, and the manipulator (excavator). A data communication manager was required to coordinate the signal or data-flow in between these modules considering the operational status of IES such as; excavation start/completion, truck detection, terrain model update, emergency stop, local sensing, GPS/motion sensor data handling, and so on. This paper presents the role and functions of this data communication manager. After every possible operational status of IES operation was identified, a protocol of each communication process in the form of string-type was made. The components of IES are connected with either wired or wireless network. Therefore, they can communicate with the manager using socket (TCP/IP) communication. The data communication manager is also capable of accessing a web-based project management information system, which constantly updates the performance of excavation robot to online database.

Aug 1, 2013

By David L. Anderson

"The government o f Canada has, since 1981, been under intense political pressure to modify its foreign direct investment (FOI) regulatory regime(1). To date the government's response has been limited to administrative and ""cosmetic"" changes: substantive issues have been largely ignored(2). However, as long as the economy continues to flounder , the Foreign Investment Review Agency (FIRA), as it is presently formulated , will continue to be an easy target for government critics . This phenomenon, in conjunction with the virtual certainty of a federal general election within two years, suggests that changes to the FIR Act will be seriously entertained by the present government.Recent events indicate that if change s are made, they will likely entail the adoption of a special-sector approach within the existing framework of a general screening system(3). Since this approach is currently employed in Australia(4), it would seem to be appropriate, from a public policy perspective to study that country's experience in developing and operating such a scheme. In doing so, I shall focus on the mineral sector; the rationale for doing so is as follows. First, this sector served as the focal point of the Australian FOI regulatory debater(5), Second , with the exception of the oil and gas industries, the non-petroleum mineral sector is one of the few areas of the Canadian economy wherein the Trudeau government has adopted an explicit domestic ownership target(6). Third, the non-petroleum mineral sector is, undoubtedly, a prime candidate to be denoted a s a special-sector if such a framework were to be utilized by the Canadian government!"".Although international comparisons are fraught with danger , a Canadian/Australian comparison is particularly appropriate(8). Both countries have reasonably similar economic, political and social structures . Furthermore, as noted above , Australia is the only other western country which employs a general screening mechanism for FOI. In addition, it utilizes a special area approach ; within this scheme, an explicit target of a minimum of 50% Australian ownership of all new resource projects has been formulated and clearly promulgated to all of the relevant interest groups. This policy, broadly defined, has been in place for more than six years and during this time the Australian mineral sector has, by world standards, prospered(9). Hence, the Australian experience in designating the mineral sector as a key area within a general screening system, should be of interest to Canadian policy-makers."

Jan 1, 1984

By E. H. Kranck

Introduction Baffin Island is still too in-accessible to be of interest to the mining industry. However, twenty years ago few people dreamed of mining iron ?ore in Labrador. A journey by air to the most remote places in the Arctic is today no more remarkable than a trip to Europe, and the technical difficulties of mining minerals of high value are not insurmountable. Some ?observations concerning the geology and mineral possibilities of Baffin Island, the largest of the Arctic islands, may therefore interest the members of the Institute, in spite of problematic practical value of the subject. The following short account is mainly based on observations made during the Baird Expedition of the Arctic Institute of North America last summer 1950), and on information available from earlier expeditions. Early Work Baffin Island was one of the first parts of Canada to attract prospectors. Frobisher sent a shipload of rocks, which he believed contained precious metals, from Baffin Island to England. This attempt, however, was a failure and no further serious prospecting work has, so far as I know, been done. During the past few years geological mapping has been carried out by the Geological Survey of Canada (Fortier. Davison, 1949-1950) in the southern parts ?of the island, along the coast of Hudson strait. In 1942, Weeks mapped the coast from Pangnirtung to the head of Cumberland fiord, and Netteling river up to Netteling lake. In the northern parts of the island, only scattered observations have been made ?by Bell, Watkins, Baird, and others.

Jan 1, 1951

By Q. Shi, Q. Feng

"The influence mechanism of chlorite on the flotation of pyrrhotite was investigated through flotation tests, Zeta potential measurements, optical microscope photos, solution ion measurements and absorption measurements. It is observed that, the addition of chlorite influences the flotation of pyrrhotite seriously. The IEP (isoelectric point) of pyrrhotite and chlorite is 7.6 and 4.3 respectively, in the condition of slight alkalinity, both pyrrhotite and chlorite are negatively charged, and the hetero-aggregation will not occur. With the existence of oxygen in solution, the iron ions are dissolved from pyrrhotite surface because of the oxidation of pyrrhotite during pulp conditioning. The dissolved iron ions adsorb onto the surface of chlorite in the forms of iron hydroxyl and iron hydroxide, and the adsorption results in the opposite charge of chlorite surface. As a result, the hetero-aggregation between pyrrhotite and chlorite occurs. The adsorption of chlorite changes the surface property of pyrrhotite and restricts the adsorption of amyl xanthate onto pyrrhotite surface, and then decreases the flotability of pyrrhotite.INTRODUCTIONIn sulfide ores processing, magnesium silicate bearing gangue minerals often report to the concentrate causing downstream processing problems as well as increased smelting costs. Talc,chlorite and serpentine are gangue minerals commonly encountered in complex sulfide ores (Engel, Middlebrook, & Jameson, 1997; Pietrobon et al., 1997; Witney & Yan, 1997; Chen, Grano, Sobieraj, & Ralston, 1999a, 1999b; Bremmell, Fornasiero & Ralston, 2005; Senior & Thomas, 2005; Wang, Somasundaran, & Nagaraj, 2005; WieseHarris & Bradshaw, 2007). All of them are characterized with uniform crystal structures consisting of silicon-oxygen tetrahedron and magnesium-oxygen octahedron. The magnesium-oxygen octahedron layers are broken during the liberation of serpentine to expose the magnesium-oxygen bonds with strong ionicity and hydration, which results in natural hydrophilicity of serpentine. In water, the hydroxyl on serpentine surface ruptures and dissolves into the aqueous phase while the Mg2+ remains, resulting in surface positive charge (Tao, 2012). As serpentine has a positive potential at alkaline condition, it is therefore likely that it will attach through electrostatic attraction to the negatively charged mineral surface and reduce both the flotation rate and recovery of target minerals (Lu et al., 2011). For talc, characterized as good natural hydrophobicity, the liberation comes from the interlaminar fracture to remain molecular bonds on surface with weak hydration. Being naturally hydrophobic, talc easily reports to flotation concentrates, thus reducing concentrate grade (Shortridge, Harris, Bradshaw, & Koopal, 2000; Beattie, Huynh, Kaggwa, & Ralston, 2006). Meanwhile, both molecular bonds and magnesium-oxygen bonds are exposed on chlorite surface when liberation occurs, resulting in moderate natural hydrophobicity between serpentine and talc (Tao, 2012). And thus the mechanisms of influence of chlorite on sulfide ores are more difficult to study."

Jan 1, 2016