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By L. E. Gutiérrez

A new filtration model based on porous media transport theory is presented. It predicts capacity and final moisture content in the filtered cake as a function of design and operational variables at the plant. FilterSim® is the computer code where this new model is programmed. Application of FilterSim® to ten-month operation of an industrial copper concentrate filtration plant is shown on a daily basis and using a single set of internal parameters for the whole period. Average error is less than 5%, both in capacity and moisture estimation. FilterSim® abilities to optimize industrial filtration plants as well as to estimate future budgets are illustrated with several real examples.

Jan 1, 2007

By J. Wickens

"Campbell Mine is dedicated to quality management in the form of a Continuous Improvement (CI) Operating Philosophy. This paper discusses that philosophy, why and how it is being implemented in the milling facility, and some of the challenges experienced to date. Examples of mill CI team projects and results are described. This paper describes practical experiences for those who are considering or are in the process of adopting a CI operating Philosophy.INTRODUCTIONCampbell Mine is 100% owned and operated by Placer Dome Canada Ltd. The mine is located in Balmertown, Ontario approximately 300 km northeast of Winnipeg, Manitoba. Campbell Mine has produced over s,000,000 ounces of gold since commencing operation in 1949. The operation is profitable and continues to be a major contributor to the gold production of Placer Dome Inc.At Campbell Mine, the concept of Continuous Improvement (CI) is being implemented to make further improvements to safety, quality, productivity, and subsequently profits. CI is not a ""program"". It is a way of doing business that concentrates on improving the system rather than finding fault and being resigned to the status quo.CI focuses on involving all employees in the decision making process and tapping their expertise to improve every facet of the business. In the past, many solutions were simple ""band-aid"" fixes treating the symptom, only to see the problem resurface again. With CI, solutions endeavour to address the root cause of problems and eliminate them permanently. Another primary goal is to eliminate unilateral decisions that benefit a small group but have a negative effect on the whole system."

Jan 1, 1995

By R. E. Bou Serhal

Many miners are exposed to dangerously high levels of noise on a daily basis. Over the past 15 years, a continually increasing number of occupational hearing loss has been reported from the mining community in the United States, of which, more than 95% is attributed to prolonged noise exposure. Although the noise exposure levels may differ between coal miners and metal and non-metal miners, in the absence of noise control at the source, the solution is the same: use of personal hearing protection devices (HPD). While protecting the miners? hearing it is also essential to no longer hinder their ability to communicate. With access to an advanced HPD that is customized to the miners? ears we are able to combine these two requirements. Using an intra-aural instantly custom molded HPD miners are protected from high levels of noise. The HPD is equipped with wireless capabilities, and contains both a speaker and an In-Ear Microphone (IEM). Therefore, the miners? speech may be captured from inside the ear and transmitted to the remote listener. This IEM signal is relatively noise-free since it is isolated from the background noise. The IEM speech signal, however, is ?boomy? and is missing some high frequency content, making fricative consonants hard to understand. Nonetheless, the IEM speech signal is correlated with the natural speech signal and may be manipulated through statistical techniques to more closely resemble natural speech. By improving the intelligibility and quality of the IEM signal, numerous applications may be enabled. One use of the enhanced IEM signal will be for radio communication. Using wireless radio communication in a noisy mining environment is sometimes the only practical and affordable solution to allow communication between miners equipped with personal hearing protection devices. Traditionally, one of the weaknesses of such wireless radio communication lies in the lack of designating receivers: whether they are the intended receiver or not, all those carrying a radio receiver are subjected to the broadcasted signal. The current work will detail a new concept of a "radio-acoustical virtual environment" where the radio signal will only be received by miners within a given spatial range, such range depending on the user?s vocal effort as well as the ambient and perceived background noise levels.

Aug 1, 2013

By J. Holder

"A key barrier to vertical mineshaft construction is the construction access required for workers. A suspended work stage is used to provide this access for the mechanical, electrical and structural applications and other tasks. Work stage design is complicated considering the numerous types of construction activities that are executed simultaneously, the confined environment in which the work stage operates, the significant corrosion attack that is present, the weight limitations imposed by the mechanical hoist systems, and the risks associated with worker safety. Also complicating the design, these structures and their construction environment can vary with time. Hence, they can be described as 4D structures. The author has discovered significant synergies and advantages with integrating engineering design with detailed three-dimensional (3D) fabrication design. The significant reduction of minor design errors needing field correction will be underscored. The tender process is also accelerated since the design output is fabrication shop drawings including a detailed quantity takeoff output which lists each component required and its specific quantity. The paper presented will document the numerous advantages to the project using this approach. INTRODUCTION A key barrier to vertical mineshaft construction lies in the access for the workers to execute the construction. Suspended work stages are used to provide this access for the mechanical, electrical and structural applications as well as other tasks. The design of such work stages is complicated considering the numerous types of construction functions that need to be executed simultaneously, the confined environment in which it operates , the significant corrosion attack that is present, the weight limitation imposed by the mechanical systems for suspension, and the risks associated with worker safety. Also complicating the design, these structures and their construction environments can vary with time. They can be described as 4D structures with the fourth dimension being time. This design is a time consuming process. The post tender award is meticulous and requires strong teamwork between the steel fabricator and the consulting engineer. This teamwork may or may not be present and is dependant on the experience and relationship the team members have working together as well as other factors."

Jan 1, 2019

By Robert W. Plummer

"This paper describes the use of Geographic Information Systems (GIS) as a tool for mineral exploration by using the Eskay Creek area of northern British Columbia as an example. Data entry, analysis and output are discussed. Examples of some of the capabilities of the technology are presented.The main benefit of the technology is being able to perform complex and sophisticated searches of large and diverse data sets to highlight exploration targets. A GIS is a powerful data management tool that can be used in mineral exploration. It is a computer based system that is designed for the collection, storage and analysis of objects and phenomena where geographic location is an important characteristic. The main function of the GIS is to produce information for the geologist from a variety of sources (geology, geophysics, geochemistry, mineral deposits and so forth) quickly and efficiently. This allows the geologist to examine large amounts of data in a fraction of the time than can be done using conventional manual methods."

Jan 1, 1992

By T L. Horsley

The change from a seasonal to a continuous mining operation at Cassiar has been accompanied by increased emphasis on the preventive maintenance of mining equipment. This paper describes how equipment maintenance is organized, and details some maintenance practices that have proved advantageous to the Cassier operation. Introduction Cassiar Asbestos Corporation Limited is currenly carrying out an open-pit mining operation at the 6,300-foot elevation on McDame mountain in northern B. C. A 6-mile road connects the mine to the mill and plantsite at the 3,500-foot elevation. Ore concentrate is delivered to the mill via a 3llz-mile tramline. Naturally level ground does not exist in the mine area. The weather is typical of mountainous regions, exhibiting wide and rapid variations in temperature. It is generally wet and windy at the mine elevation, and a heavy snowfall is common. The rock types vary from a soft, sheared serpentine to massive serpentine, to medium-hard, friable sediments to hard, blocky volcanic flows.

Jan 1, 1964

By A. Fakhimi

The effect of porosity on mechanical behavior of rock has been studied in the past using both experimental and numerical techniques. One important aspect of this study that has not received much attention is the role of void size and distribution on the mechanical behavior of rock. In this study, the CA2 computer program that is a hybrid discrete-finite element program for two-dimensional simulation of geomaterials is used. Numerical specimens with different macro-void sizes are loaded uniaxially. The Young?s modulus, Poisson?s ratio, uniaxial strength and crack initiation stress are studied. The numerical results are compared with the database of experimental tests on Plaster of Paris specimens containing Styrofoam spheres with different void sizes and porosities. It is shown that the macro void spatial distribution is partly responsible for the scatter of the experimental data. It is also shown that not-only the porosity but also the pore size can affect the deformability, crack initiation stress and rock strength.

May 1, 2009

By A. Hasselbring

Sub-Level stoping was used in this country at least as early as 1912, at the Magpie mine in Michipicoten. The fundamental principles of the system are the same wherever it is used, but modifications have been adopted in the Michigan iron mines and in several Canadian mines. It is a system whereby a suitable body of ore may be developed quickly and worked cheaply, with a low initial expense, and by miners of quite ordinary ability. The basic method, described in the following pages, may be modified to meet conditions where one or more factors are not in accord with normal sub-level stoping requirements. In suitable ground, sub-level stoping is probably the most satisfactory method yet devised for underground hard-rock mining. It is so simple, straightforward, and safe that no special training of a crew is necessary. Any miner capable of drifting and raising can carry on the work necessary for sub-level stoping after the shaft has been sunk. The method is suitable, however, only for reasonably wide ore-bodies, the minimum width of ore to which it can be economically applied being somewhere in the neighbour-hood of thirty feet. The development programme is simple. Assuming, for purposes of illuslustration, an ideal ore-body, two thousand feet long, dipping nearly vertical, and varying in width from forty to a hundred feet, this programme would be as follows. The shaft should be sunk on the footwall side about sixty feet outside of the ore-body and near its centre. Levels are then established at suitable intervals, usually 125 feet. On each level, a cross-cut is run to the ore-body, and there a main-haulage drift is driven in either direction to the end of the ore. Cross-cuts are then run at 25-foot intervals, so that ore-chutes can be spaced about 25 feet centre to centre each way. It is not necessary that these cross-cuts be extended to the walls of the ore-body, if the position of the walls is known; they are extended just far enough to make room for the correct location of the chutes.

Jan 1, 1934

By N. B. Clarke

LIMESTONE, as a name, covers a great variety of stone consisting of varying amounts of calcium carbonate, magnesium carbonate, and impurities such as silica, alumina, and sulphate of lime. In the iron and steel industry, limestone is roughly divided into two classes, namely Calcite, when the magnesium carbonate content is below 10 per cent, and Dolomite, when the magnesium carbonate is over 10 per cent. In practically all metallurgical melting, the quality of the finished product is related to the character of the slag, and limestone is used as a flux to achieve the proper analysis and consistency. The function of the slag is to absorb the undesired elements of the bath and also to act as a protective cover over the metal. The carbonates of calcium and magnesium are the effective agents in fluxing, and the silica, alumina, sulphur, and other foreign matter are objectionable impurities which should be as low as possible, totalling not over S per cent and preferably below 3 per cent, since all of these so-called impurities must be fluxed by the lime and magnesia of the stone. When the lime and magnesia of the stone have to be used to flux its own impurities, there is that much less of these two oxides left for fluxing the impurities from the balance of the charge, and, as a result, more lime-stone must be used than is desirable with good practice.

Jan 1, 1939

By C. J. Li, J. L. Feng

In the present study we focuses on developing the poroelasticity model that deals with adsorptioninduced permeability change mostly occurred in porous media constituted several phases such as coal. The underlying pressure induced by adsorption is obtained by Virial expansion form, which is substantially founded on statistical physics. The corresponding thermodynamic pressure applying on the pore surface is then used to detail the pore pressure and further to evaluate the macroscopic volumetric strain and the porosity. In the process of physical adsorption, the adsorbed phase is in thermodynamic equilibrium with the gas phase regardless of pore size, and the corresponding chemical potentials are all equal. The relationship between surface strain and volumetric strain is derived under infinitesimal deformation conditions to gain an explicit formulation of pore surface area with respect to volumetric strain and porosity. After the formulation of surface stress modified by the Langmuir isothermal adsorption is derived, the differential micromechanical constitutive equations of porous media are obtained. By supposing that the ratio of current permeability to initial is equal to the cubic ratio of current porosity to initial porosity, the differential equations for permeability change is consequently derived. The numerical simulations by the present model for permeability change of coal induced by adsorption of CO2 and CH4, respectively, are presented under confined stress conditions. The predictions from the model are good in agreement with the experimental data of sorption-induced permeability change of coals in the literature.

Jan 1, 2015

By H. W. Smith, D. Guerin

"This paper describes the development of a dynamic model for a full- scale (64 tonnes/hr) grinding circuit consisting of an open-circuit rod mill feeding a ball mill operating in closed circuit. The object of constructing such a model is to investigate the static and dynamic behaviour of potential control schemes. Model selection, data processing and parameter estimation are discussed, and static and dynamic results of simulations are presented. Conclusions are drawn with regard to the adequacy of the model for such studies, and likely limitations on control of such circuits.IntroductionThe model developed here is intended to represent the grinding behaviour of the grinding circuit at the Lake Dufault division of Falconbridge Copper Mines Ltd. This circuit has been fully described elsewhere. At the time of the work described, the ball mill discharge was fed to a four-cell flotation bank , the tailings of which are combined with the rod mill discharge in the cyclone feed pump sump. As the emphasis in this study is on grinding behaviour, and as only I per cent of cyclone feed material is removed in these cells, no attempt has been made to include flotation behaviour in the simulation. One effect of the presence of flotation cells in the grinding circuit is, however, to necessitate somewhat finer grinding than might otherwise be needed: this will have effects on mill parameters.The paper is organized as follows. First the selection of models is discussed, paying particular attention to the problem of selecting simple, yet adequate, flow models for the mills. Then data gathering is described. The method of deriving mill model parameters is explained, and the results presented. Mass balancing of cyclone data and the determination of cyclone model parameters are described. The linking of the models into a full simulation is outlined, and sta tic and dynamic results presented. Finally, the results are discussed and conclusions drawn ."

Jan 1, 1980

By I. Paredes, R. Díaz, H. Henao

Smelting of copper concentrate generates a significant amount of dusts which are collected in electrostatic precipitators. This material, which is a complex oxide of Cu, Fe, S, As, Sb, Bi and others, is difficult to recirculate into the smelting process due to the reported high concentration of arsenic. However, the dust also has concentration of copper above 10wt %, aside from reported contents of silver corresponding as much as 25wt% of the total inventories of this element in the smelters. Thus, it is of economic and environmental interest the development of a process able to reduce the concentration of arsenic in the dust and produce a material suitable to be recirculated into the smelting process. The present experimental work shows the results of a process of dust sulfidization-oxidition able to remove more than 65wt% of the arsenic present. INTRODUCTION Copper sulfide deposits worldwide exhibit increasing concentrations of arsenic. One case of interest would be the copper ores from the northern zone of Chile, which report high concentrations of enargite (Cu3AsS4) (Revista química, 2015) (Latinominería, 2014). The obtained concentrate from this ore is treated in a Fluidized Bed Roaster, producing calcines with low concentration of arsenic (<0.5 wt% As). This material is suitable to be treated in a Flash Furnace. At the roasting process, the arsenic is volatilized and then precipitated as fine particles of complex oxides. Most of this particulate material is removed from the gas stream through a device called Electrostatic Precipitator (Minería chilena, 2014). The experimental results reported in the literature indicate that arsenic present in these particulate materials (or dusts) cannot be eliminated in oxidizing atmospheres (air) or with inert gases (N2) in a Fluidized Bed Roaster even at temperatures as high as 700°C. There is also information that even the recovery of valuable metals from the dust is difficult through hydrometallurgical processes (private communication). This is how in some foundries these dusts are considered environmental liabilities. Regarding the decomposition of enargite (Cu3AsS4) in neutral atmosphere, it is reported in the literature (Padilla, 2001) that the main chemical reactions are:

Jan 1, 2019

By P. Stantke

Glue, thiourea and chloride are the common reagents which are used in copper electrorefining to achieve fine-grained and smooth copper deposition. While thiourea and chloride are clearly defined chemical substances, glue is a natural product consisting of a mixture of amino acids in different constituent parts. The amino acids are continually degraded in the electrolyte by hydrolysis until they finally become completely inactive. This effect is well-known, largely constant and balanced by the continuous dosing of glue. In contrast, the behaviour of glue in the batch container is not always foreseeable. The glue can become partly or completely inactive by contamination with acid or bacteria, for instance. Usually this is not noticed, and partly or fully inactive glue is added to the electrolyte over a longish period, with the result that the copper growth is significantly impaired. Examples from operational practice show that, with the help of the CollaMat system, partly or fully inactive glue batches can be quickly detected.

Jan 1, 2007

By B. D. Wood, J. A. Fowler, H. S. Grütter, J. M. Kong

Abstract- The phased approach used by De Beers for diamond exploration is briefly outlined. The Victor kimberlite is one of 19 kimberlites in a cluster near Attawapiskat, Ontario. The progress at the Victor kimberlite is summarized, and the operations are described within the framework of this staged approach. An evaluation program is currently under way on the Victor kimberlite, but although results are encouraging, insufficient diamonds have been recovered to permit disclosure of estimates for the grade and value.

Jan 1, 2001

By Paul A. Glapa

Quality is much more than providing a product that functions properly. True quality is a way of thinking, a way of doing business, and, ultimately, a way of satisfying a customer?s long-term needs. A true commitment to quality requires a top-down management commitment, with a willingness to change what needs to be changed and to expand upon ?best practices? that are already done well. Is there a cost to creating and maintaining a quality program? Of course there is, but the cost of not having a focused program is much greater. We have come to regard quality as an investment that pays dividends to both the supplier and customer. The lack of quality costs everyone and the customer pays the ultimate penalty. With modern, highly engineered surface mining equipment the end user calculates cost in terms of lost production (revenue), not simply the cost of the part. Bucyrus International, Inc. is a company that has listened to its customers and has dedicated itself to implementing an advanced quality program. The ultimate goal being the creation of a high quality product with extended reliability for the customer. The result is reflected in Bucyrus? current product offerings and highlighted by the new 495HF electric rope shovels at Albian Sands mine.

May 1, 2003

By H. K. Taylor

"As a mining engineer with over 50 years&apos; experience in underground operations and mine planning, I appreciate the enormous amount of work that went into the paper; and despite an imbalance between geology-geostatistics and the profit-earning actions of mining and treating (possibly because of sponsorship only by the Geological Society), I agree with probably 85% of the detail. But the paper fails to build on its own sound foundations and, like many predecessors, drifts instead into idealism. Even the starting quotation from the US SEC Form S-18 is little more than a platitude. An American consultant (l) has observed: ""an evaluation that accepts ore reserves as guaranteed because their definition meets SEC criteria is an invitation to disaster"".Idealism enshrines at least two myths that have bedevilled definition over the last several decades. The first is that the only purpose of &apos;ore reserves&apos; is to promise successful new mines, and that &apos;ore reserves&apos; must necessarily follow feasibility studies.In practice, the identification of what is likely to be mined if a mine is started must often be done on broad economics long before the feasibility study, and there may be only little later flexibility. The second myth is that there can be a perfect deposit with a simple exploration-appraisal-development sequence (the paper&apos;s Figure 2) against which all inferiors can be matched. If the field of definition be regarded as a pyramid, the quest for perfection and the imposition of rigid promises upon the terms &apos;ore&apos; and &apos;reserves&apos; drive definitions so near the apex (or the bottom right corner of Figure I, if preferred) that little is left to define. The process is reminiscent of the legendary super-medicine, the one so powerful that the patient had to be in perfect health to take it!"

Jan 1, 1992

By D. A. McIsaac

In these days, when mass production seems to be the watchword of all industrial companies, nothing is left undone to attain this end. Transportation, where necessary, becomes a question of very great importance. For this reason every mechanical contrivance known to man is employed, with its resultant advantages. So successful has man&apos;s ingenuity been that, offhand, we are inclined to say that practically all transportation on a large scale is done mechanically, that is, where speed and economy are desiderata. Granting this, one would think that to read a paper on the horse before your honourable and highly technical Society would surely be a waste of time, and that any Company employing old-fashioned &apos;horse&apos; power would certainly be very much behind the time, to say the least. However, the fact remains that the biggest industry in our country today-coal mining-must use horse power to a great extent, being compelled -both by considerations of economy and by necessity. For this reason,&apos; in the production of coal under present conditions, the pit horse is of great importance to this industry and is to be considered seriously as one of the units that help to make coal mining a success or a failure. Hence, in employing horses as a power for transportation, care must be exercised in selecting the animals, and the care of this power must be considered as seriously as any other department of such an organization. In selecting a pit horse, several things must be borne in mind, that is, one must get as much horse power as possible in as compact a form as is practicable. This determines the type of horse we must use, which is of very great importance under our present conditions of coal mining. With low roof, steep grades, and forced production, a distinct type of animal must be selected.

Jan 1, 1930

By R. Anthony Hodge

Who/what is ?community?? What are most communities interested in, what do they care about? What has happened in the past? What is happening today? What is hoped for tomorrow? What are the lessons and keys to success?

May 1, 2006

By D. A. McIsaac

In these days, when mass production seems to be the watchword of all industrial companies, nothing is left undone to attain this end. Transportation, where necessary, becomes a question of very great importance. For this reason every mechanical contrivance known to man is employed, with its resultant advantages. So successful has man&apos;s ingenuity been that, offhand, we are inclined to say that practically all transportation ?On a large scale is done mechanically, that is, where speed and economy are desiderata. Granting this, one would think that to read a paper on the horse before your honourable and highly technical Society would surely be a waste of time, and that any Company employing old-fashioned &apos;horse&apos; power would certainly be very much behind the time, to say the least. However, the fact remains that the biggest industry in our country today-coal mining-must use horse power to a great extent, being compelled both by considerations of economy and by necessity. For this reason,&apos; in the production of coal under present conditions, the pit horse is of great importance to this industry and is to be considered seriously as one of the units that help to make coal mining a success or a failure. Hence, in employing horses as a power for transportation, care must be exercised in selecting the animals, and the care of this power must be considered as seriously as any other department of such an organization. In selecting a pit horse, several things must be borne in mind, that is, one must get as much horse power as possible in as compact a form is practicable. This determines the type of horse we must use, which is of very great importance under our present conditions of coal mining. With low roof, steep grades, and forced production, a distinct type of animal must be selected.

Jan 1, 1930

By L. Kraszewski

"IntroductionPortland cement is produced by burning an accurately proportioned mixture (raw feed) of finely ground limestone, silica, alumina, and iron oxide. The kiln discharge (clinker) is a chemically complex mixture of calcium silicates, aluminates and ferrites which when ground and blended with from 2 to 5 percent of calcium sulphate is sold as Portland cement.ManufactureThe most common raw materials are limestone and clay or shale. The raw mix is finely ground and heated to about (2600°F) 1430°C to decompose the calcium carbonate and combine the calcium oxide with silica, alumina and iron to form a partly fused clinker. The clinker is then ground, usually with a small proportion of calcium sulphate (gypsum), which regulates set. Cements with special properties are produced by varying the oxide composition and also by adding small amounts of chemical agents at the clinker-grinding stage or later.Clinker is manufactured by either wet or dry process methods. In the wet process, raw materials are prepared, blended and fed to the kiln as a water slurry (about 30-35% water) . In the dry process, raw materials are prepared, blended and fed to the kiln as a dry powder (about 0.5% water). The processing procedure is as follows:"

Jan 1, 1982