Search Documents

By A. Jeffkins

Visibility is restricted when operating load haul dump vehicles resulting in a number of serious accidents in the Ontario Mining Industry. One of the leading causes of these accidents is the inability of the equipment operator to see clearly people, objects or hazards around the machine. Previous line of sight testing by the research team found specific machine characteristics were responsible for blind spots and impaired visibility. In order to identify feasible design modifications a computer simulation program, Classic JACK 3.1, was utilized. Program features include human factors analysis, which allows evaluation of line of sight and operator posture in order to decrease risk of musculoskeletal injury. Research within the virtual computer environment consisted of a Visibility Audit and a Target Audit in order to quantitatively determine how certain components of the LHD design affected the line of sight around the vehicle. Results indicate that modifying the LHD light brackets, engine profile, cab posts and other components will enhance visibility. The addition of cameras located on the front and rear of the vehicle were able to enhance the operator?s sight lines to previously obstructed areas. Modifications to seat height and the operators orientation both improved sightlines and decreased risk factors associated with back and neck musculoskeletal disorders.

May 1, 2003

By S. F. Dudka, T. Dang, M. L. Wong

Abstract - The Nui Phao W-F-Cu-Au-Bi deposit is located in one of the poorest regions of northern Vietnam. The deposit is currently undergoing a pre-feasibility study by Tiberon Minerals Ltd., with a view to developing what would be the largest WO3 mine and one of the five largest fluorite mines in the world. The project is being planned in close compliance with World Bank and national guidelines for environmental and social protection. Development of the mine is anticipated to bring the following benefits: remediation of serious pre-existing environmental conditions (natural and anthropogenic heavy metal contamination and acid rock drainage); provision of employment and training, and thereby wealth, to local communities; significant tax and royalty payments to government, which will be reinvested as social spending; and development of municipal and industrial infrastructure to build sustainable post-mining communities. The role of governments at all levels is critical in guiding and facilitating this process. This paper was written prior to development of the mine, and relays the intentions of the developers. Future studies will be needed to evaluate the degree of attainment of sustainable development objectives, both during mine operation and after closure.

Jan 1, 2003

By Ahmad Hemami

A working code is developed to simulate the forces that are involved in the process of penetration of a bucket into bulk media during loading and excavation. The result of this work can be integrated with the simulation software that many manufacturers of heavy earthmoving machines introduce for training purposes. The simulator programs for machines such as backhoes, loaders, LHDs and the like, used for operator training, are usually only based on the kinematics of the machine. As a result, there is no indication of the effect of the medium when the cutting tool of such a machine touches the excavation material. This is like moving the machine in the air. Feeling the resistance force of medium to cutting by a bucket or blade during loading and excavation is more realistic, both mentally (by vision) and physically (feeling resistance in pedals and levers). The results from force simulation can be used by feedback in creating simulated resistance in these training gears, similar to what is done in flight simulators for aircrafts. In addition to serving for the above purpose, the results of this work can be used as a tool for examination and verification of the effect of a control policy for automation of loading and excavation of bulk media. So far no commercial product has been introduced that has such a capability, despite some extensive research on the subject.

Aug 1, 2013

By J. A. Dubinski

One of the greatest threats of mining in hard coal mines are underground fires, which in the past often resulted in the mining disasters. Implementation of scientific principles of fire fighting into practice contributed to a significant reduction of fire hazard in coal mines. However, despite numerous achievements of science in the fight against the underground fires, they still occur creating a potential hazard for the miners and contributing to generate significant costs of fire-fighting operations, the temporary suspension of production or loss of longwalls. This concerns both spontaneous fires and exogenous ones. A significant decrease in the number of spontaneous fires was the result of cooperation between Polish scientists with experts in the field of new methods of fire hazard prediction and selection of new fire prevention and fire hazard monitoring methods. A significant part played here researchers from the Central Mining Institute. The original method of endogenous fire risk assessment based on calorimetric tests of coal and developed mathematical model of the process of coal self-heating allow to predict the risk of spontaneous fires and select proper fire prevention measures adequate to the involved risk. The frequency of exogenous fires is in the last few years is low, but their share in the total number of fires is relatively high and constitutes about 30%. This results from the prevention activities, carried out regularly in mines which are aimed at reducing the fire hazard connected with the use of fire-resistant conveyor belts and other non-metallic materials. Further directions to reduce the hazards connected with underground fires should focus on improving the methods for monitoring hazards together with automation of fire fighting operations.

Aug 1, 2013

By Denis J. Kemp

The 20th Century saw changes in the mining and metallurgical industry not only technically but also in social and environmental expectations. As projects continue to become larger to maintain competitiveness the visibility of their potential impacts raise concerns among many groups. The need for transparency, openness and early engagement of all parties are fundamental to assure success. An equally important task is to anticipate the standards that will be required to meet society?s expectations in the 21st Century. Historical Observations The mining industry of the 18 and 19th Century was dominated by opportunistic Companies and individuals with an entrepreneurial flair for adventure and risk. Those who promoted had the chance of great reward, while those willing to risk their life were assured a short one for their efforts because of the physical and health dangers that abounded. Disregarding conditions miners rewards were high even in those days, with an average Cornish miner known to be earning two pound a month in 1800. Coal and iron ore mines were driven by the needs of the industrial revolution and were the first to embark on larger scale output. Base metal mines were smaller as industrial demands for their use did not start to expand greatly till the late 19th Century. Electrification, the automobile and the 1st World War drove the increased demand for a variety of metals. Early mines were foul smelling and dusty and what was taken from below ground left spoil piles around the surface countryside after recovery of the coal or concentrate. The image of barren blackened hills is one that is easily conjured up and is an environmental legacy that still lives with us today.

May 1, 2002

By R. Maxwell

"At Opemiska Copper Mines we have, over the past four years, operated 300 cu. ft. and 700 cu. ft. flotation cells as roughers, scavengers and cleaners and found them competitive with conventional flotation cells on a cu. ft. basis on all phases of flotation.The economics are very much in favour of the large cells for the following reasons:Power consumption is 35 to 40%, of conventional machinesMaintenance cost is about 20 to 25% of conventional machinesSpace required is about 30 to 35% of conventional machinesInstallect cost is about 40%, of conventional machinesTo put the above in more concrete terms below is what we are doing at Opemiska:1. Increasing mill capacity from 2000 to 3000 T.P.D. and will use only 5Cff, of the flotation space for 3000 tons that we used for 2000 T.P.D. with conventional flotation machines.2. Will require only 10 flotation cells for 3000 tons against 85 conventional cells for 2000 tons.3. Cells will be, one 2000 cu. ft. rougher, six 700 cu. ft. scavengers (2 banks of 3 each) and one cleaning circuit using three 300 cu. ft. cells.You will note that in this 3000 ton per day plant, we are going to have only ten cells. Had we put in conventional cells for this tonnage, we would have needed 120 cells."

Jan 1, 1970

By D. Ferrand, C. Villeneuve, N. Bensalah

"La conciliation entre l’expansion de l’industrie minière et les exigences du développement durable représente un grand défi. Face aux différentes controverses touchant cette industrie, la dernière décennie a été marquée par une plus grande mobilisation de l’ensemble des parties prenantes. Cependant, plusieurs carences persistent en matière d’opérationnalisation du concept de développement durable. Ce défi met en cause la responsabilité partagée entre les parties prenantes. Il exige le renforcement des responsabilités gouvernementales et l’instrumentalisation de bonnes pratiques de responsabilité sociale des entreprises. En aval, s’impose la gestion intégrée de l’usage des produits miniers et la promotion de l’innovation et de la recherche.ABSTRACT Conciliation between expansion of the mining industry and sustainable development requirements represents a great challenge. With regards to the various controversies touching this industry, the last decade was marked by a great mobilisation phase of all stakeholders. However, there are still many shortcomings regarding operationalization of the sustainable development concept. This challenge involves shared responsibility between the stakeholders. It requires strengthening government accountability and instrumentalization of good corporate social responsibility practices. Further down the chain, the use of mining products and the promotion of innovation and research must be achieved through integrated management."

Jan 1, 2015

By Alex Henderson

The underground hard rock mining industry has had little change since the mobile equipment era began in the 1970s. Equipment has become larger and faster but has not kept pace with the following challenges: ? Improvements in safe production, ? Increasing demand for metals, ? Environmental improvements, ? Decreasing grades, ? Increasing depth of mining, ? More metal from underground vs. surface mining, and ? Energy and green house gas awareness. We are on the cusp of a new mining era and must rethink how underground hard rock mining must change in order to meet these challenges. This paper will show historical changes and propose a set of guiding principles for the next era of mining. Mining has changed over the last century. Initially mining was primarily an endeavor carried on by private companies with minor environmental controls and few social expectations other than employment. In the mid to later part of the century the mining industry was facing new challenges: deeper mines, the London Metals Exchange markets for pricing, and environmental concerns related to acidic rock drainage coming to the forefront. In today?s context, mining has evolved in complexity with the social and environmental aspects equally or surpassing the technical complexities such as expanding from mining hard rock to laterites, and mining lower grades or at greater depths. Nowadays, communities must be considered as partners, both locally and globally and the increased international visibility pushes the mining sector to take a more balanced approach to the business of mining (Fig. 1).

May 1, 2011

By S. D. Logan

This presentation describes a lightweight automobile body structure concept developed at DaimlerChrysler to support a high fuel-efficiency vehicle project. This body structure consisted primarily of large thin-wall magnesium castings and resulted in a more than 40% weight reduction with a minimal cost increase over a conventional steel structure while achieving significantly improved structural performance as evaluated through CAE simulations. One concept vehicle was built for the purpose of demonstrating concept feasibility. Several slides showing the prototype build process are presented. The presentation also describes several large thin-wall die casting body applications that are in current production or have been used in recent production automotive applications and identifies areas where further development could improve the chances of a magnesium intensive body structure becoming a production reality at a later time.

Jan 1, 2006

By T. Macpherson

Drawing on past research experience with sprayable polymer mine support agents (TSLs), Spray On Plastics Ltd. has developed a TSL ground support system called RockWeb. Using a relatively new polyurea polymer technology, RockWeb has been engineered to solve problems encountered underground with polyurethane liners by incorporating rapid curing, moisture insensitivity and superior physical performance. RockWeb possesses a unique, patented ability to be sprayed in a ?cobweb? like consistency allowing the applicator to span fissures in the rock, ensuring no initial defects in the liner, and maintaining design thickness over highly irregular surfaces. This ability, coupled with the high strength and elasticity of polyurea, allows RockWeb to mitigate rock movement through yielding, while maintaining intimate surface confinement. RockWeb provides reduction in logistics through the transport of 1/25 of the material quantities required for shotcrete, rapid deployment rates of as little as 30 minutes per round, and immediate return to the work area. This paper will discuss the technology and advantages of RockWeb as well as opportunities for overall mining cycle cost reduction. The safety benefits, as well as health and environmental considerations regarding application of isocyanate-based liners will also be discussed.

May 1, 2009

By J. Gillies

"Those of you who were at last years C.M.P. meeting are aware there was discussion at that meeting concerning the best method of assisting the assayers of metal mines to exchange new ideas and methods of assaying. The opportunity to advise you of what came of that discussion is very much appreciated.There are several societies, including the Chemical Institute of Canada, the Spectroscopy Society and others that could be of some assistance to assayers. However, since these societies cover a rather broad field and not many mine assayers have the opportunity to attend their meetings, it was felt that an organization oriented to the specific needs of the mine assayers would be of more value to them.Several years ago an attempt was made to hold meetings for the benefit of assayers in conjunction with the Conference of Metallurgists held each year by the Metallurgical Society of the C .I.M.M. This did not work because very few of the mine assayers attended the meetings.With the very evident success of the type of meetings the C.M.P. have and the excellent groundwork done by your secretary, Mr. Stevens, in talking about this to mine management and assayers at many mines across the country, it was decided to hold a meeting at Noranda on October 8 to discuss how best we could help ourselves solve our problems.For the initial meeting it was felt that perhaps it would be better to start with a smaller group, so invitations were sent to mines in Ontario and Quebec that were geographically fairly close to Noranda."

Jan 1, 1970

By Clifford R. Stanley

"Abstract - Reproducible analyses of representative samples for elements affected by the ‘nugget effect’ is vital in mineral exploration and reserve estimation. Unfortunately, a priori knowledge of what size of sample is representative from a mineral deposit or its dispersion train is commonly unavailable. Use of the simple ‘equant grain model’ and the NUGGET computer program facilitates determination of the sampling parameters that will produce appropriate samples for chemical analysis. Based on Poisson statistics, NUGGET can be used to determine: (1) the ‘effective grain size’ of nuggets in a suite of samples, (2) the level of representativity (precision) that samples with specific nugget grain sizes will exhibit, and (3) the sample size required to obtain a specific level of sample representativity. The program determines these sampling parameters for any element in any mineral, including solid solution minerals (e.g., Au, electrum, Pt-Fe alloy, diamond), and allows assumption of a variety of grain shapes (e.g., ellipsoids, cylinders, parallelepipeds, etc.). Furthermore, it outputs the effective number of nuggets expected in a sample of given size and the percentile confidence bounds on any element concentration affected by the nugget effect.Results from the software allow determination of effective sampling and analysis strategies that minimize the nugget effect in geochemical analysis/assaying used in mineral exploration and reserve estimation. This will not only improve confidence in the resulting exploration results or reserve estimate, but will facilitate estimation of the error associated with any subsequent interpretation or reserve figure."

Jan 1, 1998

By G. E. Agar, R. Stratton-Crawley

"The applicability of a hydrocyclone model to simulation of the cyclone banks in a multi-stage sandplant circuit producing mine back fill has been demonstrated. The model ha~; been used in conjunction with a modular computer program for circuit simulation in order to study the effect of changes in the operating conditions. It has been shown that weight recovery to sand fill increases as feed percent solids decreases, and, to a lesser extent as pressure drop across the banks increases. An increase in apex diameter also causes an increase in weight recovery. Increased weight recovery must, however, be balanced against sump an1l cyclone capacity and dilution of sand fill by fines. The predicted results from circuit simulation were in good agreement with plant data.The model has been found to be applicable to widely different ores."

Jan 1, 1979

By D. J. Houlahan

ABSTRACT Sorting has the potential to massively improve the pro?tability of mining base metal, hard-rock ores. However, several barriers to the increased application of sorting have been identi?ed, including a lack of mineral-speci?c sensors available to the industry. This paper presents the outcomes of acollaborative project to develop an induction-balance sensor speci?cally for low-grade copper and nickelores. A review of the basic principles of induction-balance sensing and of the sensor-rock interaction is presented. Early development and testing of the sensor on ores from the Thompson nickel belt in northern Manitoba is discussed. Shortcomings of the prototype identi?ed in early testing have now been over-come, leading to improvements in design and construction, as well as sensor accuracy. The improve dsensor has now been tested on additional ores from the Sudbury Basin, with good results. A discussion of potential applications is presented and recommendations for future development are made.

Jan 1, 2010

By J. N. Cram

"The comments given are to help allay generally accepted ideas that the handling of arsenic as arsenic-trioxide (As2o3J in and from off gas pyrometallurgical operation fumes is difficult, hazardous and expensive. It need not be any of these things if the basic and rather unique chemic3l and physical properties are understood and taken care and advantage of through present day technologies. These particular characteristics are:-(1) As2o3 sublimes and re-condenses, at a relatively low temperature;(2) As2o3 is, for practical in-plant purposes, insoluble in water at ambient temperatures and quite soluble in water just below the boiling point;(3) residual suspended and dissolved As 2o3 can be removed from water by complete dissolution with very little sulfuric acid, followed by the addition of small amounts of ferrous sulfate and calcium chlorate, with oxidation to the ferric and arsenite state and precipitation of an insoluble ferric calcium arsenate, thereby lowering the As2o3 content of solutions to acceptable levels. Even lower levels of non-toxic forms of arsenic solids and residual As2o3 in the water solutions can be attained by also using phosphate, and lime, along with the above.A background re past arsenic processing methods, present day operations, plus predictions re future trends, and hazards, are outlined."

Jan 1, 1979

By Simon C. Dominy, Alwyn E. Annels, Mark A. Noppé

Abstract - Mineral Resources and their subsequent conversion to Ore Reserves are of key importance to mining companies. Their reliable estimation is critical to both the confidence in a feasibility study, and also to the day-to-day operation of a mine. Together with sampling, assaying, geological and other errors introduced during interpretation and estimation, additional errors are likely to be introduced during the application of technical and economic parameters used for conversion of resources to reserves. There is thus a requirement for high-quality interpretation and estimation to be supported by high-quality data. Any company expecting to make sound investment or operational decisions must base this on both relevant and reliable information. An Ore Reserve statement generally contains a single set of grade and tonnage figures without a discussion of the potential inherent errors in these estimates. Some sensitivity studies may be run, but confidence limits are rarely quoted and, if they are, often do not take into account many of the factors that cause uncertainty in the grade and tonnage estimates. Mineral Resource and Ore Reserve estimates thus carry certain errors leading to uncertainty and risk; some of these are unquantifiable for various reasons, for which the operator should be aware. This paper presents a review of the potential sources of error that might occur during a resource estimation program, which are carried through into the reserve estimate. A number of methods are discussed that allow the estimator to be more transparent about the inherent risks in his/her estimate. Emphasis is placed on data quality, and the requirement for strong quality management to be linked to continuous improvement.

Jan 1, 2002

By A. Gillis

"In order to obtain the equipment necessary to automate the equipment it was decided that the Department of Mines and Milltronics would jointly survey the circuit. This survey involved a metallurgical study by the Department of Mines and Milltronics took sound recordings during manual operation, checking in circuit bottle necks and determining the number of sensors that could be applied.The conveyer is driven by 2 PIV drives, each has a variable speed of 3/ 1. The cross conveyer that feeds directly into the rod mill feed chute will contain an automatic sampler and will eliminate the necessity of stopping the belt feeders to take samples. At present, hourly samples are taken from this point and the circuit is upset and cycling results.The Adequate scale is very close to the rod mill to totalize and thereby give a continuous indication and the second purpose is to take a signal from it and control the solution addition to the rod mill.A pneumatic positioner was obtained and put on the scale which produces a 3 tp 15 psi signal which is proportional to the actual tonnage going across the scale. This signal was fed to a bias loader which was mounted on the control panel. From there the operator can set the amount of solution that is wanted by the rod mill. No matter what the feed rate is, the signal coming from the bias loader will follow it automatically. This in turn goes to the pneumatic solution valve (1 ½” ) and the solution goes in with the feed to the rod mill. This is only part of the solution required for dilution since the rest of it is used as a force jet for the feed to the rod mill."

Jan 1, 1965

By Joe Price

Canada?s energy future will increasingly depend on a supply of light, sweet crude oil derived from the Athabasca oil sands deposit of North-eastern Alberta. Billions of dollars are being spent on the construction of new and expanded mine and bitumen extraction plants, in situ recovery facilities, pipelines, upgrading installations and all the infrastructure needed to support these projects. The success of the existing operators has also inspired new players, anxious for ?a piece of the action? to come forward with exciting project proposals of their own. None of this investment and spin-off economic activity would be taking place today if events had unfolded differently in this part of the world some one hundred million years ago. The accumulation of sand in rivers, estuaries and in the near-shore marine environment created the great reservoirs that host the enormous oil deposits these projects are designed to exploit. Mine operators of all stripes will likely agree that there are few good ?geological surprises?. With specific reference to oil sand deposits, the geological history determines the distribution of sand, silt and clay bodies, which in turn controls the ore grade. Important design factors including everything from stable pit slope angles to tailings properties reflects events that took place millions of years before. An understanding of the sequence of events that resulted in deposition and preservation of the sediment and oil are important to sound design for both mining and in situ facilities. A geological history of the region is described. Site-specific examples from Syncrude?s operating mines are used to illustrate some of the geological factors that can present design challenges.

May 1, 2003

By Jason Prno

Context ? Climate change an issue of global significance ? Research is lacking ? Study initiated by the David Suzuki Foundation, led by ArcticNorth Consulting Industry Surveying ? 34% and 48% of respondents indicated climate change is already affecting operations ? Majority believed climate change would have negative impacts in the future ? Cost and uncertainty of Future impacts are major barriers to adaptation

May 1, 2010

By Jennifer Pakula

Productivity improvements in underground mining are becoming harder to find. Most mines quickly identify deficiencies in their processes and then struggle to make productivity gains beyond that plateau. One way to increase productivity in this situation is to modify existing methods of operation. Vale?s Stobie Mine has been in operation since the late 1800?s employing a variety of mining methods. Many mining advances have been incorporated over time. With the advent of mechanized rubber tired equipment, sublevel cave mining was introduced to allow economic extraction of a large low grade area. Additional productivity gains were seen in the sublevel cave area with the introduction of preloading production drill holes. In preloading, the holes are loaded with bulk emulsion ahead of the production cycle and then primed for blasting as needed. The introduction of preloading, although giving the Stobie sublevel cave process an overall productivity gain, saw an increase in oversize due to the collar priming technique employed. Handling oversize material prohibited the operators from handling additional units of optimally sized material. Prepriming, adding detonators at the toe and midcolumn of the production holes during the preloading process, was identified as a change that could reduce the formation of oversize. This paper describes the introduction of prepriming to the sublevel cave mining method and focuses on the process Stobie employees followed to ensure a safe transition to this productivity improvement.

Nov 1, 2011