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By W. D. Robbson

DR. G. W. RAMSEY (l): A study of our non-treatment silicosis autopsy material for the years 1940-43 inclusive, in addition to the common findings of fibrosis, nodules, and emphysema, shows marked thickening of the alveolar walls. This change is due to one or more of the following factors: congestion, edema, accumulation of both small and large monocuclear cells within the interstitial tissues and large monocuclear cells attached to the lining membrane of the alveolar sacs. This alteration in the alveolar walls, we believe, is one of the most important factors in producing impaired pulmonary function. Comparison of our first autopsy material of a case receiving twenty aluminium treatments beginning June, 1943, shows a striking change in the alveolar walls. In all areas free of silocotic nodules and fibrous tissue, the alveolar walls approach normal thickness and are free of cellular deposits. No change was noted in the old processes and none was expected. We believe that these changes in the alveolar walls were brought about by the aluminium therapy and that they constitute a major factor in the improved pulmonary ventilation noted in treatment cases.

Jan 1, 1945

By T. R. Heflin

The paper provides a comprehensive discussion of pump selection for the hydrometallurgical industry. Material suitability, in addition to proper size and design, will provide extended life for pumps in erosion /corrosion service.

Jan 1, 1979

By J. R. Smith

"The Lake Dufault orebodies were discovered by deep surface diamond drilling. When a reasonable amount of outline drilling had been completed, the decision to go into production was made. The fact that shaft sinking, lateral development, the detailing of the orebodies and stope preparation were to be carried out as rapidly as possible necessitated very close scheduling.After a study of varions possible mining methods, an open-stoping system using long-hole blasting was chosen. Diesel-powered Transloaders were selected for the mucking and transportation of ore from the drawpoints to the orepass.At the time of writing, the choice of mining method appears to have been fully justified, although more time will be required to arrive at true operating costs and efficiencies."

Jan 1, 1966

By G. W. Diehl, G. A. Griffiths

"Gentlemen, one week ago, I attended the University of Minnesota's Annual Symposium on Mining, in Duluth. A good part of this symposium was dedicated to mill linings of rubber.At this symposium, three mining companies published results from long time full scale tests with rubber linings in mills at four different mines. These were the Republic and Empire Mines of Cleveland Cliffs Iron Company, the Groveland Mine of Hanna Mining Company and the Eagle Mountain Mine of Kaiser Steel Corporation. These papers will be printed in due time and I will not endeavour to relate their full contents, let me only say that in three of the plants, the linings were found to be very economical compared wi.th steel, and that these three are converting over completely to rubber linings, while the fourth, Empire Mine, reported no economical results as far as the shell lining goes, whereas the grates showed promise of becoming economical. The authors of the Cleveland Cliff's paper, however, stated that design improvements in the rubber lining possibly could result in an economical lining also for Empire Mine.That rubber linings in mills, in most cases, show better wear life than steel linings, is known by most of the audience. But, one thing that has not before been disclosed by the endusers is the effect of rubber linings on the grinding economy. All three papers mentioned above reported no change in capacity or grind and two of them reported a decrease in power consumption per ton ground. Hanna Mining reported an average decrease over a three year period for one mill of over 10%. This, of course, puts the economy of a rubber lining in a completely new light. Finally, a point of interest at this meeting was that all three papers emphasized the design aspect, Thus the industry has acknowledged what I believe to be a very important fact - the design of a lining is often more important than the material it is made of."

Jan 1, 1970

By L. Tang

A seismic monitoring system was installed in 2005 at Dongguashan Copper Mine, the deepest metal mine in China. Based on the seismic events monitored in situ, the possibility of rockburst prediction and prevention is investigated in this paper. The characteristics of space-timeintensity of mining-induced seismicity and the seismic response to mining are studied in detail using the seismic data in Dongguashan Mine. A conceptual model and a criterion of assessment of hazard seismic nucleation are proposed for Dongguashan Mine. In this model, the mine seismic stiffness method is adopted for rockburst prediction within the framework of the unstable failure theory. To analyze rock failure cases in Donggauashan Mine, the rate of the ratio of stiffness of rock in nucleation area to its surrounding area is proposed as a criterion for rockburst prediction.

May 1, 2009

By G. S. Hume

Dr. K. A. Clark: No one will doubt the statement of fact that, during drilling operations through the bituminous sand beds in the Mildred-Ruth Lakes area, the core-barrel was found to contain bitumen with minor amounts of sand instead of bituminous sand. But many will doubt the interpretation of this fact as meaning that beds of bitumen occur interstratified with the bituminous sand beds. They will prefer to hold faith in the laws of physics, which deny that sand will float on oil or that fluid under pressure will not flow away through a permeable medium, until it is proved that the appearance of the oil in the core-barrel was not due to circumstances surrounding the drilling of the bituminous sand beds. The implication of the interpretation that sand is floating on oil is clear and it is unacceptable. Bituminous sand is unconsolidated sand more' or less saturated with a viscous oil. It is as difficult to conceive of bituminous sand lying on top of a body of the viscous oil as it is to conceive of unconsolidated sand more or less saturated with water lying on top of a body of water. The only difference between the two concepts is that the oil is viscous whereas the water is fluid. Oil-soaked sand placed on viscous oil would, when released, sink through the oil slowly, whereas water-soaked sand would sink through the water quickly.

Jan 1, 1947

By Craig H. B. Leitch

"In describing the alteration of porphyry systems, the term ""secondary K-feldspar"" appears to be an oversimplification. A better term would be ""alkali feldspar"" alteration, because in actual fact the replacement feldspars show gradational changes from an albite, which is important in some systems, to an alkali feldspar containing minor orthoclase molecule, to true orthoclase.There are several textural varieties of secondary alkali feldspar present in the porphyry systems studied from British Columbia, Australia and New Zealand. These include, in apparent increasing order of alteration intensity: clear albite (An10); patchwork albite (Ab5-10); chessboard albite (An0-10) "" irregular albite "" (An0Ab100 to Ab90r10); untwinned "" anoralbite"" (Ab90Or-Ab70Or30); and orthoclase (Ab440Or60-Or100)·The exploration significance of these varieties of alkali feldspar is that their gradation in composition, from sodic to potassic, may be linked to a corresponding increase in intensity of alteration. Thus, there is a tendency for more sodic alteration feldspars to characterize weak, sub-economic deposits, or the fringe zones of stronger deposits; the more potassic alteration feldspars may provide an exploration vector toward more highly mineralized zones."

Jan 1, 1981

By J. Y. Liu

In Comparison to the application of HPGR (high-pressure grinding rolls) in the cement industry and in iron ore processing, the introduction of this energy-efficient comminution technology to processing of nonferrous base-metal ores has progressed slowly as yet. In the field of minerals industry, challenges lies not only in the large variety of the feed material with respect to particle size, density, hardness, moisture and mineralogy of the material but also in complexity of the processing flowsheet, which need to be addressed from case to case based on result of HPGR comminution test work. Whereas conventional comminution test with HPGR in lab-scale or pilot scale needs quite a large amount of feed material, a compressive stressing test of particle-bed in piston-die device provides an effective way to study interparticle breakage behavior of ore material with much less feed. In the present study the effects of interparticle breakage on comminution of a copper ore has been investigated by compressive stressing of particle bed in a piston-die device. The feeds to the particle-bed stressing tests were four narrow size fractions in the size range of 0.3~3.35 mm and a broad size fraction of 0/3.35 mm. The pressures applied were in the range between 30 and 180 MPa. The results showed that the specific energy consumption increases linearly with the pressure; the product fineness increases also with the pressure, but the magnitude of this increase declines as the pressure goes up. Under the same stressing intensity, the product size distribution curve becomes steeper as the particle size decreases, so there is no self-similarity between product size distributions of different feed sizes. The suitability of a material-characterization model for interparticle breakage was verified for this ore. In addition, the effect of interparticle breakage on comminution of this ore with respect to its influence on the downstream flotation were analyzed in terms of size-metal distribution and mineral liberation.

Jan 1, 2016

By Tim Grain Joseph

This paper considers the duty cycle of an electric cable shovel and correlations with measured passive seismic responses of the underfoot oil sand material in-pit. It has been observed that the cyclic activity during operation of any shovel in the oil sands environment causes the material to deteriorate and provide a less than ideal footing for this large item of equipment, whose dead weight approaches 1500 tons with a footprint of merely 75 square yards. Consequences are manifest in the form of carbody and side frame cracks, and associated downtime, maintenance activity, cost, and subsequent loss of availability. The objective of these considerations, as part of the Oil sands Equipment Interaction Program (OsEIP); currently a joint venture between Syncrude Canada Ltd., JPi Ltd., Caterpillar Inc., P&H MinePro and the University of Alberta; is to identify and provide feedback to the manufacturer and end user adverse shovel - ground conditions. This would enable the manufacturer to incorporate greater knowledge into the design process and the end user to direct operations in an enhanced proactive maintenance stance.

May 1, 2002

By S. Mamonov, V. ?shikhin

"The purpose of work was the significant increase of copper recovery from slag at a concentrating plant. Analysis of study of slag phase composition showed the perspective of a slow slag cooling method due to its recrystallization and transition of primary copper minerals to secondary.Copper content in base slag varied between 0.71 and 0.96%. The study of a degree of copper minerals release of the slowly cooled slag in comparison with a yielding slag showed that in a flotation size grade –0.071 mm of yielding slag the weight ratio of released copper minerals grains is 58.95% against 86.73% in samples of slowly cooled slag. The process flotation sheet consists of three main, one control and two cleaner flotation operations with aftergrinding of middling products. A reagent mode was differed from a factory one by decreasing the slurry pH from 11–12 to 8–9. This paper shows research results of the slurry alkalinity impact on technological indexes of beneficiation (flotation).Industrial testing of a resulted batch of slowly cooled slag at “SUMZ” concentrating plant showed the efficiency of such processing: copper recovery to a copper concentrate increased by 15–19%.INTRODUCTIONIntensive development of mining and metallurgy industries within a 250-year period in the Ural region led to forming of approximately 315 man-made mineral formations at the territory of the Sverdlovsk region. The region contain over 32.5 billion tons of barren rocks and out of balance ores, over 1.5 billion tons of tailings, over 115 million tons of slimes, and over 100 million tons of metallurgical slag (Demin et al., 2000). Latters, at average, contain 407 thousand tons of copper, 2519 thousand tons of zinc, 7 tons of gold, and 150 tons of silver (Rudoy et al., 2011). Wastes generated in mining processing and metallurgical sector of economy contain not only thousands tons of copper and zinc, but cause significant damage to the environment where they are located. The reduction of negative impact of anthropogenic wastes on the environment as well as the storage volume reduction of valuable metals from dump slags is possible by improving the efficiency of the melting and further flotation of slags formed during this process."

Jan 1, 2016

By Peter Godbehere, Christian Desroches, Viken Baboudjian

"Noranda Copper Smelting and Refining is a unit of Noranda Metallurgy Inc., comprising the Home smelter in Rouyn-Noranda, Quebec and the C.C.R. Refinery in Montreal East. The Home smelter provides custom smelting services for a wide variety of copper and precious metal bearing concentrates and recyclable materials, producing over 200 000 tonnes of anodes and 450 000 tonnes of sulphuric acid annually. The C.C.R. Refinery has an annual production of 360 000 tonnes of copper cathode, and is a major refiner of precious metals.Over the past twenty years, Noranda Copper has developed innovative processes and operating techniques to treat the ever increasing complexity of primary feed materials, while improving the quality of its final products, working conditions and reducing environmental emissions.This paper presents an overview of the operating practices of Noranda Copper with particular emphasis on the impact of impurities in the smelting and refining processes.IntroductionThe treatment of custom materials has been practiced by Noranda Copper since commencement of operations at the Home smelter in 1927 and the CCR refinery in 1931. Copper concentrates from a wide variety of regional, North American and overseas producers account for the bulk of the 800 000 tonnes treated annually, although recyclable and secondaries have increased in importance as feed sources in the past two decades. The geographical disadvantage of the Horne smelter compared with most custom smelters located on tidewater has provided an important incentive for Noranda Copper to develop the necessary technology and operating practices at its smelter and refinery to treat high value complex concentrates and other feeds containing significant concentrations of bismuth, antimony, arsenic, lead, tellurium, mercury, etc."

Jan 1, 1995

By E. Yalçin, A. Ünal

In transitional mineralization, the sill of the underlying variogram is relatively easily estimated, but the estimation of the nugget effect may be more difficult. This study aims to determine for massive copper deposits just how sensitive the estimations of ore reserve, economic copper content, total net value, and ultimate pit limits are to the errors of estimation in the nugget effect of the spherical variogram model. A massive copper deposit which has a log-normal distribution and a spherical variogram was simulated on a rectangular grid using the turning bands method. By using the three dimensional random kriging method, the mean block grades were estimated at four different sampling densities. The ultimate pit-limits were determined by using the two-dimensional dynamic programming algorithm. To calculate the estimation errors, the values obtained by using the actual nugget effect and structured component values were deducted from the estimations obtained using the incorrect nugget effect and structured component values. For isotropic massive copper deposits, it was found that the ratio of the nugget effect to the structured component of the spherical variogram has no significant effect on either the block grades estimated by the kriging method or on the ultimate pit limits.

Jan 1, 1992

By D. M. Cruden

"When two discontinuities form a tetrahedral wedge in a rock slope, a factor of safety for the wedge can be simply calculated (if motion is driven only by gravity and resisted only by friction) from plots of the normals to discontinuities on an overlay of a polar, equal-area spherical projection to which the great circles of a similar equatorial projection have been added.IntroductionThe stability of slopes in rock masses is often controlled by the discontinuities that exist in the masses. In particular, the geometry of the discontinuities constrains the ways in which the mass may fail. Displaying the orientation of the discontinuities on a spherical projection has been found to be a useful way of identifying possible failure modes. The most concise display shows the orientation of the normals (or poles) to the discontinuities that compose the fabric of the rock mass. Computer processing of large samples of discontinuity orientations is necessary if the sampling biases identified by Terzaghi (1965) are to be routinely corrected. Fortunately, displays of the poles to discontinuities (or pi diagrams) are relatively easily produced on the line printer of a computer or by a computer plotter (Cruden , 1978; Ramsden and Cruden, 1979). Unfortunately, further analysis of the stability of a rock mass has tended to use traces of typical discontinuities on a spherical projection rather than pi diagrams; examples may be seen in Hoek and Bray's book (1981)."

Jan 1, 1990

By R. Tessier, R. Grant, C. Bazin

"Brunswick Mining has investigated grinding media optimization for the purpose of improving the flotation feed and regrind product size distributions to enhance metal recoveries. The paper presents findings in the on-going testing of various sizes and shapes of grinding media. Breakage rates are used as an aid to assess the effect of grinding media. Results of empirical and phenomenological analyses demonstrate the importance of adequate selection of media sizes on the milling operation.INTRODUCTIONBrunswick Mining and Smelting operates one of the world's largest lead and zinc mine near Bathurst, New-Brunswick. The No. 12 ore body is an extremely fine grained volcanogenic massive lead, zinc, copper, silver, iron sulphide body between two metamorphosed sedimentary and felsic volcanic rock units. Pyrite content is about 60% with 20% non-sulphide minerals, mainly silica and chlorite. The operation is currently processing 10,500 tonnes of ore per day in conventional crushing, grinding, differential flotation and dewatering circuits. Details on the circuit can be found elsewhere (e.g. Hendriks and Ounpuu, 1985; Grant et al., 1991).The mill has operated for more than 25 years and despite the past milling experience, there has been much disagreement as to the required grind size. Since 1964, fineness of the flotation feed ranged from 60% to 80% passing 400 mesh (37µm) and averaged slightly over 71%in1992. Results from mineralogical analysis (Petruk and Schnarr,1981; Coleman, 1988), Brunswick metallurgical laboratory (Grant et al., 1991; Shannon et al., 1992) and Lakefield pilot plant tests (Hendriks, 1984; Hendriks and Ounpuu, 1985) clearly indicate that improved metal recoveries can be achieved by an increase in the fineness of grind, and more specifically by maximizing the amount of material in the 15-25µm range."

Jan 1, 1993

By A. Kozlowski

We present research on cable fault location methods for mines where coal dust and methane explosions are a frequent potential hazard. The methodology and devices for low- and medium voltage cables fault location are well known and applied in classical power distribution networks. They are based on solutions for underground mines with a high risk of explosion. The lack of a safe solution for the location of a fault has contributed to the initiation of a research project by a group of Polish companies. The consortium consists of research institutes (Institute of Innovative Technologies EMAG, Tele and Radio Research Institute, Central Mining Institute GIG-KD ?Barbara?), Silesian University of Technology and a private entrepreneur MARTECH PLUS. Fast and exact determination of fault location is one of the important factors for minimizing power outage time. The lack of technical solutions to obtain measurements in a secure way leads to the use of the methods connected with a high risk of explosion. For example, the application of high energy can lead to arc discharge where there is a fault in insulation, creating the risk of an explosion. Measurements of methane concentration along the analyzed section of the cable reduce the risk; however the shock wave generated by the electric arc may raise coal dust and make an explosive mixture, which is an object of ignition. Low energy methods, like those based on reflection waves, have low sensitivity for high- and medium-resistance faults. This technique has difficulties in joints, which create false echoes. The fundamental problem is to determine the topology of the network using a reflectogram and find anomalies of a different nature ? not only open and short circuit. Included in the scope of the project is an analysis of Polish legal regulations related to fault location and operational work for low- and medium-voltage networks. Two of the methods used on the surface were selected as feasible to implement under explosion hazard conditions. In the process of development of the fault location methodology, installation features characteristic of underground mines were used, namely access to the whole length of a cable. This is the attribute that provides an opportunity to do measurements that are usually not possible for typical surface power nets. To carry out laboratory tests, a dedicated measuring stand with various types of cables was built. The authors describe the principle of operation of the fault locator and the results of the laboratory tests carried out on the cables with built-in damage (prepared for tests). Results of the work will be the basis for the next stage of the project associated with operational analyses of the prototype.

Aug 1, 2013

By J. C. Botham, T. D. Brown

"Coke is the most costly item in steelmaking via blast furnaces . Recent innovations in cokemaking have been directed toward reducing this cost while simultaneously improving coke quality and expanding the range of coals used in the process. It is also important to meet increasingly stringent environmental legislation.Improvements in coke quality have been achieved by novel blend selection procedures, by charge density control using both selective pulverization and partial briquetting, and by the use of modifying additives.The Canadian Carbonization Research Association provides a focus for Canadian cokemakin g research which has demonstrated these technologies in a series of pilot-scale experiments."

Jan 1, 1980

By M. Ghiani, P. Carbini, R. Ciccu, C. Del Fà

"This paper is concerned with the problems inherent in the efficient and economical processing of the fine fractions of a coal from the Sulcis basin (Sardinia, Italy) whose characteristics are typical of low-rank coals occurring in the Mediterranean region. Three different techniques, based upon surface properties, are examined. Flotation can be very efficient from both a technical and economic point of view, provided care is taken in the modulation of the flotation pulp. Interesting results have been obtained with oil agglomeration and this method could be economically feasible. Finally, electrical separation has proven a viable technique, although it entails preliminary drying.Besides discussing the problems encountered in the experimental research, some significant results of general validity are also given. They demonstrate that cleaned products can be obtained with fairly interesting recoveries, thus opening the way to advanced research aimed at setting up the most suitable technique for industrial application. IntroductionAs a result of the oil crisis, which caused a major upset in world energy supplies, the last ten years have seen a revolution in the energy policies adopted.In particular, the status of coal, which seemed destined to decline in view of the availability of liquid fuel, has had to be re-examined. The need to meet energy demands under improved reliability conditions and controlled prices through a broader and more flexible diversification of sources of supply has evoked, especially in highly industrialized countries, a renewed interest in coal. The result has been a consistent increase in demand and production as well as investments in new mines and the reinforcement of the infrastructure.This turn of events has also lead to a re-evaluation of young low-rank coals, hitherto considered uneconomical and thus neglected, because of their low heat value. In fact these coals, which have a high ash content, may also be relatively highly contaminated with sulphur. The above drawbacks, which still today preclude the widespread use of these coals, are bound to create even greater problems in the future as increasingly restrictive environmental control imposes, without exception, recourse to cleaner fuels."

Jan 1, 1986

By Charles Tkaczuk

Key issues ? Process control is a corporate function implemented locally. ? Security and documentation is mandatory requiring standard practices. ? Publish and communicate activities (do not re-invent the wheel). ? Payback metric system for all projects. ? Partnering with vendors based on experience, expertise and joint R&D. ? Focus on phased process control projects and distribution of costs. ? Integration of services and functions. ? Application of global standards. ? Big picture application thinking.

Apr 1, 2005

By T. A. Apelt, B. J. Elliot

"In September 1993, the flash furnace at Kalgoorlie Nickel Smelter, KNS, was brought off line after almost 12 years of operation. This is a record campaign life for a flash furnace. The furnace was' totally rebuilt and the capacity of the plant increased from 540 000 tpo to 750 000 tpa of concentrate throughput. The throughput increase was' achieved through the construction of a 525 t/day oxygen plant and upgrading of various plant ancillaries. A number of significant design modifications were also built into the flash furnace and oxygen enrichment was implemented in the operation of the Peirce-Smith converters.This paper discusses the rebuilding of the flash furnace and design modifications made to furnace equipment and ancillary plant. Some preliminary post-startup operating data are presented.IntroductionIn September 1993, Campaign 6 of the flash furnace was concluded and the furnace brought off line for rebuilding. The campaign length was almost 12 years and set a new record for campaign length. Planning for the rebuild took place over the last five years of the campaign. A number of modifications to the design of the furnace and the ancillary plant were planned to coincide with the furnace rebuild. The furnace was rebuilt and recommissioned in 70 days. The increased plant capacity of 750000 tpa has been achieved by the construction of a 525 t/day oxygen plant and modifications made to ancillary plant which centred around increased p~ control, efficiency and hygiene. This paper examines the development and implementation of the modifications made to the furnace and ancillary plant. Preliminary post-shutdown performance data are presented."

Jan 1, 1995

By C. R. Kerr

"This paper describes the revisions to the heating and ventilating system at the Frood-Stobie mill, which resulted in substantial savings in energy costs.IntroductionInco Metals Company, a unit of Inco Limited, is involved in the mining and processing of nickel-copper ores. The Ontario Division of Inco Metals consists of 10 operating mines, with 5 mines and open pits on a standby basis, and 10 pro- cessing facilities, located in Sudbury, Port Colborne and Shebandowan. In 1980, the Ontario Division's energy expenditures amounted to $87,000,000.Due to the accelerating cost of energy, the Division established an Energy Management Program in 1975 to define, evaluate and implement measures to reduce energy cost and consumption per unit of output by 10% by 1980. This falls in line with the goals set by the mining and metallurgical task force on voluntary energy conservation.To effectively implement the program, Plant Committees were established at each plant and mine area, with an energy management coordinator appointed to coordinate the activities. The Plant Committee's responsibilities include identifying the major areas of energy consumption, isolating areas with large potential losses and determining what action should be taken to improve energy efficiency.Within a five-year period from 1975 to 1980, the Ontario Division has been able to cut its energy consumption by 8.9 trillion BTUs, the equivalent of 1.5 million barrels of oil."

Jan 1, 1981