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By J. J. Jonas, G. R. Stewart, A. M. Elwazri

Two important parameters for dynamic recrystallization can be derived from the changes in the strain hardening rate: the critical strain for initiation of dynamic recrystallization and the point of maximum softening. In this work, these values are determined from the flow stress-strain data obtained in continuous compression testing in the range 900-1100°C. The resulting strains are used to calculate a kinetic model of dynamic recrystallization for two materials: 304 austenitic stainless steel and a hypereutectoid plain carbon steel. The mechanical parameters used to define the proposed model are confirmed with quantitative metallographic analysis of the recrystallized microstructure.

Jan 1, 2004

By Jean Vavrek, Rob Barber

"What is CIM’s role on a planet-wide scale?That question has been coming back to the forefront of many discussions regularly in the months since we came on board as Executive Director and Vice- President International. CIM, by its name and by the nature of its history and make up, has mainly been a Canadian entity. It has been created by an act of Canadian Parliament and it is set up to work within the Canadian federal and provincial framework.Yet the name CIM is one well known and recognized for quality and professionalism worldwide. One could say that CIM has established a level of brand recognition that transcends it name and its origin. CIM has also evolved with the times, as the world has evolved and more so as the world of mining has evolved. So we stand today with a fairly large portion of our membership residing outside Canada and outside the United States. We also stand today looking back at the role CIM has played in events that we have been partners in organizing outside Canada; and for a long time CIM has provided insights into what is going on in the rest of the mining world by inviting authors and by featuring topics from around the globe.Today, Canada is still a leader in the mining industry. Canadian mining companies are involved in exploration and operations around the world. Canadian operations serve a good portion of the global demand of many metals and minerals, recently adding diamonds to the slate. Canadian expertise in various areas also makes Canada a good base for exporting a wide range of products and services around the world."

Jan 1, 2004

By Jane Spooner

"The papers presented in this edition of the Bulletin cover some of the business issues that face mining companies exploring or operating in jurisdictions outside Canada. While technical innovations may, generally, be seen as fast-moving and farreaching, these papers also show that changes in approach and thinking continue to be evaluated and implemented.The Forum paper co-authored by Roger Taplin of McCarthy Tétrault LLP and Marchand Snyman of Muratie Investments Pty Ltd. highlights the quite radical changes that have taken place in South Africa’s mining industry with the introduction of the Mineral and Petroleum Resources Development Act, 2002, in October of that year, together with the Broad-based Socio-Economic Empowerment Charter for the South African Mining Industry and the Mineral and Petroleum Royalty Bill of March 2003."

Jan 1, 2004

By T. R. Roy

"This paper presents an objective model for the estimation of fire risk potential of an underground coal mine panel by the bord-and-pillar method of mining where extraction is carried out by depillaring with caving. The fire risk rating procedure for the estimation of fire risk potential involved in the panel is described in detail. The model developed thereof is tested with the field data collected from different collieries across the country along with the laboratory data for critical assessment of fitness of the model. Some results showing the validity of the model are also cited here. Introduction The occurrence of fire in underground coal mine panels is quite common in India and elsewhere. These fires cause extensive loss of resources.Although substantial work has already been done by different research organizations, the problem has not been fully eliminated.The causes of panel fires depend not only on the spontaneous heating susceptibility of coal, but also on the extraneous conditions created in the panel due to the mining operations. From the studies done so far by various organizations, it is apparent that two types of parameters associated with spontaneous heating of a coal mine panel exist: intrinsic and extrinsic. Parameters related to the nature of coal, i.e., its physicochemical characteristics, petrographic distribution and mineral make-up are intrinsic, while the extrinsic parameters are related to the atmospheric, geological and mining conditions such as scope of leakage of air into the panel, wetness of mines, heat dissipation capacity of the panel, gassiness of seam, geological disturbances, method of extraction, size of panel, etc.Banerjee (1982) identified twenty-two mine parameters such as spontaneous heating susceptibility of coal, method of mining, geological disturbances, quality of overburden, degree of consolidation of coal mass, scope of accumulation of coal fines, etc. that can influence spontaneous heating in underground mines. He used the terms “high” and “low” for fire risk rating of each of these parameters. Since this approach is oversimplified, it can not determine the exact fire risk potential of an underground working."

Jan 1, 2003

By Steve Lalancette

Centre Jardin Lac Pelletier (CJLP) has been a leading actor in the revitalisation of closed mining sites in northern Québec for over 20 years. Over that period, CJLP developed a cost-efficient technique that transforms sterile mining residue into a substrate able to support a resilient ecosystem. Using a unique mix of organic matter, fertilisers and selected plant species, this technique rapidly builds a microorganic fauna and a layer of humus that will sustain the creation of vegetation coverage. The coverage is composed of over 13 different plant species, each having a unique role in the development of a resilient ecosystem, from soil stabilisation to nitrogen fixing. Considerably less expensive than traditional methods using civil engineering techniques, it does not require the use of heavy machinery or the spread of topsoil. This technique has been successfully used to restore over 20 sites in Québec such as Joutel, Yvan Vézina and Louvicourt. It is a proven technique that has passed the test of actual implementation. The presentation will review the biological, production and economic aspects of the technique through the revitalisation of the Joutel site.

May 1, 2011

By G. F. Doggett

In describing accounting methods at Lake Shore Mines, it is the intention of the writer to limit the discussion to the principal features of the system used in securing cost figures and other statistics. The subject can be conveniently treated under the following divisions: (1) Time-keeping and Labour Distribution (2) Supplies: Handling and Distribution (3) Method of Assembling Data for Cost Purposes (4) Details of Operating Costs Time-Keeping and Labour Distribution After a new employee has gone through the routine of being 'hired on', he is assigned an employment number corresponding with the group applying to his occupation. This is for identification purposes in the plant and time office. He is also given an individual serial number, the use of which will be refer-red to later. On entering and leaving the plant, each employee passes through the clock room adjoining the time office, where he registers the time in and out on time recorders, on the clock card (Figure 1) bearing his name and number. It is the duty each morning of the time clerk to extend the hours worked by each employee, as indicated by the clock for the previous day, and at the end of the half-month period the total hours are multiplied by the rate and entered in the space provided for total wages at the bottom of the card.

Jan 1, 1935

By Jean Vavrek

What is CIM?s role on a planet-wide scale? That question has been coming back to the forefront of many discussions regularly in the months since we came on board as Executive Director and Vice-President International. CIM, by its name and by the nature of its history and make up, has mainly been a Canadian entity. It has been created by an act of Canadian Parliament and it is set up to work within the Canadian federal and provincial framework.

Feb 1, 2004

By F. Dubuc

"The Adams Mine of Jones & Laughlin Steel Corporation is situated on the Boston Township iron range near Kirkland Lake, Ontario. Eight different orebodies have been outlined, with a total open-pit crude tonnage of. about 100,000,000 tons or the equivalent of 30,000,000 tons of concentrate. The ore consists of fine-grained, well-bedded Early Precambrian iron-formation composed essentially of alternating layers of chert and magnetite. Grade averages about 22 per cent magnetic Fe.The iron range varies in width from 3,000 to 4,000 feet and is made up of several horizons of iron-formation, cherty ""quartzite"" and volcanic rocks. The latter consist mostly of basic lava flows and minor amounts of tuff. Dips are rarely Jess than 50 degrees, and the range is believed to represent an overturned limb of a major synclinal structure. Dykes of syenite and lam prophyre, along with local younger diabase, intrude the rocks of the iron range."

Jan 1, 1966

By A. R. Miller, M. C. Bétournay, D. L. Barnes

"A number of successful proof-of-concept projects have been carried out to replace conventional power application, such as diesel and rechargeable batteries, in underground mine vehicles. This has led to the development and testing of the world’s first fuel cell production vehicle, a mine locomotive. A fuel cell loader is being built and tested.This paper provides an insight into other projects that are being carried out. Some are related to further underground applications, and some to further research, such as refueling options, power plant durability, and vehicle automation.Also outlined is an evaluation of the overall mining applications and advantages this technology can bring to underground mining, including the facilitation of automation and tele-remote operation."

Jan 1, 2003

By Z. Bibak, S. Banisi, A. Ghasemi, E. Nematollahi

"The major importance of liners in grinding is their role in providing an appropriate trajectory for the charge. Since it is not possible to study the charge movement by direct observation in operating industrial mills, this task is accomplished by physical (laboratory), and/or, mathematical (software) methods. Because of the high cost and a longer time required for a physical analysis, mathematical simulations have become more common. Simulation of the effect of liner shape on the charge movement has provided a means to select a proper design based on the operational objectives and conditions. Furthermore, the liner shape changes due to wear and impact during operation, which will influence the charge trajectory. This adds more of an incentive to use simulation. These changes in liner could be predicted through liner profile measurements during operation and/or simulation. In this research, an inhouse developed DEM software called KMPCDEM © was used to simulate the charge movement in industrial plant SAG mills. A geometrical method of implementing the shell liners on SAG mills at the Sarcheshmeh (9.75×4.87 m) and the Gole-E-Ghohar (9×2.05 m) operations facilitated the software simulation. Point by point implementation of the measurements of liner profiles of these mills enabled the study to trend the change in the charge movement as the liners wear. Comparison of the simulation to a laboratory mill (1 m diameter) showed that the difference between the measured and predicted charge impact point, shoulder angle and toe angle were 6, 4 and 3°, respectively. INTRODUCTIONComminution is the most energy intensive operation constituting the major portion of operating and capital costs of a mineral processing plant. In the last decade, a vast number of research was aimed at studying various aspects of grinding with the aim of performance improvements (Davis, 1919; Mishra & Rajamani, 1990; kalala, Breetzke, & Moys, 2008). Mill liners transfer the input power to the charge and play a significant role in affecting the motion of the charge (Mclvor, 1983; Mishra & Rajamani, 1990; Radziszewski, 1997; Van Nierop, Glover, Hinde, & Moys, 2001; kalala et al., 2008). Lifters are usually used with mill liners to extend their life and to enhance the grinding and impact breakage efficiency. Mill lifters are used to raise the grinding media and ore to transfer the energy from the mill to the load (Rezaeizadeh, Fooladi, Powell, & Weerasekara, 2010)."

Jan 1, 2016

By Andre du Preez

Emergency Fall Arrest System Rio Tinto?s Primary Objective: ?To achieve repeatable controlled safe deceleration rates during emergency fall arrest activation (Ontario OHSA Regulations) ?Must operate effectively on mine specified steel shaft guides.

May 1, 2013

By J. Paraszczak

For mining companies facing strong international competition and unfavourable commodities’ prices, automation of underground operations has the potential to increase productivity and help cut costs. However, despite considerable technological progress in this field, there still remain many problems to overcome. Furthermore, successful implementation of automation depends also on numerous operational, organizational, and even human factors. In this context, this paper briefly reviews technological progress with regard to different underground operations. Following that, several issues related to implementation of automated equipment and systems are presented and discussed. Particular emphasis is put on the factors whose importance is often underestimated. Some recommendations in this respect are also given. It is stated that the success of an automation project is a function of many “winning conditions,” which may be created through very thorough planning and preparation. It is also underlined that despite achievements made, a vision of a man-less underground mine is not yet as much a matter of near future as it may seem.

Jan 1, 2004

By Y. Nara, N. Aramaki, M. Maruyama

Evaluation of three dimensionally non-uniform strain distribution in rocks under various conditions such as in water or under freeze-thaw cycles is of significant importance to understand their complex deformations and fracturing mechanisms. For this purpose, we developed an image analysis method which can evaluate or “measure” the three dimensional (3-D) strain distribution in rocks. The proposed method utilizes the 3-D images of rock under initial and deformed configurations, which are obtained by some imaging techniques such as X-ray computed tomography (X-rayCT). In the proposed method, the obtained 3-D images are divided into multiple sub-regions of interest. For each sub-region, the strain is evaluated utilizing 3-D affine transform with unknown coefficients to be determined. In the first step, 3-D voxel level displacements at multiple representative points in each sub-region are computed by 3- D digital volume correlation technique between the comparison images and the initial-guess of the transform coefficients are obtained. In the second step, referring to the initial-guess of unknown transform coefficient, they were optimized in sub-voxel level by finding optimum digital volume correlation between the comparison images, which can evaluate the transform coefficients with higher precision. From the calculated transform coefficients, the strain was directly obtained through the spatial derivative of displacement based on affine transform. In this paper, along with the description of the proposed method, the evaluation of deformation in a lignite specimen due to immersion in water was presented as an application example. As the 3-D imaging technique, micro-focus X-rayCT was applied. The result showed that the induced dilatational strain field due to the initiation and extension of cracks in the specimen was clearly captured. Therefore, authors believe that the proposed method can be applicable to various problems in rock mechanics.

Jan 1, 2015

By Alice H. Zhu

Belt conveyors are widely used in materials handling industries. The bulk materials which can be transported include ores, coal, earth, grain, limestone, wood chips, fertilizer components such as potash and many others. Along with the new technology development and enhanced industrial automation requirements, belt conveyor instrumentation has also been modernized to improve conveyor availability and performance. Traditionally, belt conveyors are equipped with emergency pull cord switches to shut the conveyor down, misalignment switches to signal the belt offline condition, speed sensors to detect the belt slippage, and level switches to prevent material plugging in the discharge chute. Belt rip detectors are also normally provided for long belt conveyors. As a rule, equipment condition monitoring is not automated at most operating facilities, but is performed manually by maintenance staff via time-based surveillance. The new generation of condition monitoring instrumentation and control equipment can be successfully utilized to design a reliable, cost-effective, and centralized monitoring system, capable of monitoring a wide variety of mechanical equipment. The implementation of the condition monitoring automated system can provide continual monitoring of the plant equipment to ensure safe operation of the equipment to its required capacity. Any abnormal behavior of the motors, gear reducers and pulleys can be analyzed, alarmed, and recorded immediately, so problems can be detected and resolved before critical components failure. Therefore, the current trend is to provide the belt conveyors with condition monitoring system in addition to the traditional instrumentation, where temperature probes and vibration sensors can be installed on motors, gear reducers and all pulleys. Another innovative development is a three-in-one type belt rip detector which combines laser, tray and cord type detection together to ensure a prompt belt tear indication. The purpose of this paper is to present the latest development of belt conveyor instrumentation and introduce the application of newly developed instruments.

Nov 1, 2011

By E. Roman E.

A novel anode slime purification process was developed and tested at pilot scale in the Chuquicamata Refinery. The process consists of three main stages: First, an atmospheric alkaline leaching at 90°C, under controlled pH and ORP operation parameters where metalloid impurities are preferentially removed from the anode slimes with high efficiency. In a second stage, alkaline washing of the mud leached with addition of reducing agent, with the intention of reducing the silver of the AgCl to metallic silver releasing the chloride, and finally, copper and other remaining impurities are leached out in mild conditions (60°C, one hour in sulphuric acid). In a side process Se, Te, and Sb are recovery with high efficiency from the alkaline liquor as chemical grade products. The global balance shows a high mass loss yielding a final product with high precious metal and low impurities content showing advantages in both a technical and economic point of view with a clear environmental sustainability. This treatment allows either the direct sale of the purified anode slimes or its pyrometallurgical treatment to obtain metal doré without emissions of Se, Sb and As. Chemical mechanisms for this novel process are also described.

Jan 1, 2007

By S. M. Grillo, Fiori. M., R. Bornioli, C. Marini, S. Fadda

Abstract - The Na-feldspar orebodies in Sardinia occur along structures belonging to a regional ENE-WSW system that developed during the late stages of the Hercynian orogeny, and that was reactived during the Alpine orogeny. The main petrographic facies include granitoids, albitized granitoids, albitites (more or less rich in quartz), and albitites containing Mg minerals. Field observations and petrological and geochemical data point toward a metasomatic origin for the albitite orebodies. Albitization involved depletion of K from K-feldspar and biotite, dissolution of free quartz, and a lowering of Sr/Na2O and CaO/Na2O ratios in the protolith, under conditions of a positive thermal gradient. The absence of later K-metasomatism implies that, during a subsequent decline in temper- ature, the composition of the albitizing fluids was modified by an influx of meteoric or other waters.

Jan 1, 1996

By A. J. Vivyurka

"This is a talk about the experiences that Rio Algom Mines Ltd. has had in the Elliot Lake uranium area trying to make the tailings more compatible with the surrounding environment. To get a better idea of the problem that we are associated with we have to go back to the location. The Elliot Lake uranium area is situated about half way between Sault Ste Marie and Sudbury and is about 20 miles north of Lake Huron. In 1950, uranium was discovered along the north shore of Lake Huron and by 1961 we had up to 9 mines operating in the area. Then the United States Atomic Energy Connnission withdrew their contracts so that at present there are only 2 mines operating. From all the mines that we had operating, we ended up with 7 tailings areas. From these 7 tailings areas we have 5 sites where we have active treatment or rehabilitation. There is the Pronto site where we are treating uranium tailings and copper tailings. There is the Lacnor-Nordic site which is located just out of Ellio Lake. The Milliken-Stanleigh site is in the Crotch Lake area. The Panel tailings is off the north end of Quirke Lake and finally there is the operating property of Rio Algom Mines at Quirke Lake.To understand fully the problem with this rehabilitation we have to look at the constituents of the ore. The ore body is a quartz conglomerate with uraninite and brannerite as the uranium bearing minerals in a fine ground mass of quartz, sericite and pyrite which separates the larger quartz pebbles. The approximate composition of the ore is: 80% quartz, 13% chlorite, 7% pyrite and 0.2% uranium minerals. The processing method also adds a few constituents to the final tailings."

Jan 1, 1975

By S. M. Grillo, M. Fiori, R. Bornioli, C. Marini, S. Fadda

The Na-feldspar orebodies in Sardinia occur along structures belonging to a regional ENE-WSW system that developed during the late stages of the Hercynian orogeny, and that was reactived during the Alpine orogeny. The main petrographic facies include granitoids, albitized granitoids, albitites (more or less rich in quartz), and albitites containing Mg minerals. Field observations and petrological and geochemical data point toward a metasomatic origin for the albitite orebodies. Albitization involved depletion of K from K-feldspar and biotite, dissolution of free quartz, and a lowering of Sr/Na2O and CaO/Na2O ratios in the protolith, under conditions of a positive thermal gradient. The absence of later K-metasomatism implies that, during a subsequent decline in temperature, the composition of the albitizing fuids was modified by an influx of meteoric or other waters. Copyright © 1996 Canadian Institute of Mining, Metallurgy and Petroleum.

Jan 1, 1997

By A. Azad

SAGD (Steam Assisted Gravity Drainage) is an in-situ oil recovery technique for heavy oil reservoirs. The technique has been successfully applied to many projects in the past 25 years and the process has been, now, well understood. It is now believed that geomechanics plays an important role in SAGD and should be considered in numerical or analytical modeling. Currently, geomechanics is numerically modeled through combining a multi-phase flow and a geomechanical simulator. Numerical modeling is, however, time consuming, need lots of input data, and could not be used for quick decision-making purposes. To decrease the modeling time, this study based on a new version of the Reis drainage model, proposes coupled mathematical model and reserves the effect of geomechanics in the process. Results showed a perfect match with the past experimental and numerical data.

May 1, 2009

By Glenn D. Lyle

As part of an initiative to improve value in mining, CEMI is developing a handbook on best practice in mine design. Various formats were examined, and of these, the wiki was selected as being most suitable. Being web-based, its global reach and capability of being continuously updated allows the wiki to evolve as new knowledge is generated, and to capture the diversity of experience of practitioners in the mining industry. While wikis have many advantages in terms of organizing content and searching, their ability to be edited by users is often seen as a negative characteristic for quality control. To ensure reliability of information content, author attribution, specific authorship models, and a peer review process have been implemented, in addition to the standard version tracking capability of wikis. The first phase of the project concentrates on topics related to underground hard rock mine design. The scope will be expanded to cover other aspects of mining as the project matures. Strategic partnerships with various organizations, such as the CIM, and CANMET, are being formed to provide a wide range of seed material to stimulate growth of the site. www.minedesignwiki.org

May 1, 2011