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By D. C. Brady

"Within six months from award of a project management contract, Les Mines Dumagami Limitée, Cadillac, Quebec, was operating its new hoisting facility. This was accomplished with less than a six-week shutdown of mine production while still maintaining shaft access for underground maintenance.The work involved installing a refurbished /3.5 ft diameter double drum hoist, replacing a timber headframe with a newsteel headframe, increasing the ore bin capacity from 500tons to 1000 tons, constructing a new substation, and upgrading related facilities.This paper describes the work and methods used by various contractors, Les Mines Dumagami Limitée and J.S. Redpath Mining Consultants Limited to bring this project to a successful completion. It discusses the history of the project from proposal stage through to the design, procurement, scheduling, and construction management. The paper also comments on problems that were encountered and the methods used to overcome them.IntroductionThe Donald J. Laronde Mine of Les Mines Dumagami Limitée (Dumagarni), a gold and copper producer, is located in northwestern Quebec, approximately half way between Val d'Or and Rouyn. The mine started production in the spring of 1988 and the first gold bar was poured in June 1988.Following a request by Dumagami, on February 22, 1989, J.S. Redpath Mining Consultants Limited(Redpath) delivered a proposal to increase hoisting capabilities from 1500 tpd to a minimum of 2500tpd. Although various concepts were considered, Redpath proposed a new hoist house along the same shaft axis as the existing hoist, and located on the site of the existing substation. They would then provide a new substation, replace the headframe with a largersteel structure , gain extra storage capacities by increasing the bin heights, and raising the roof of the bin house accordingly.Although underground mining would have to be stopped for a month, the mill production would be maintained by feed from Dumagami's open pit.Figure 1 shows the original plant layout and Figure 2 represents the general arrangement after the project was completed . Table 1 compares the original hoisting facilities to the new facilities.On March 2, Dumagami awarded Redpath a contract that included preliminary engineering, detailed engineering, procurement and contract administration, and later added construction management. The preliminary engineering refined the initialconcept, selected major equipment, and prepared schedules and capital cost estimates for the total project."

Jan 1, 1991

By G. F. Trainor

At the Canadian Natural Resources Limited (CNRL) Horizon Mine they use Wenco International Mining Systems Ltd (Wenco) Fleet Management System to monitor and control their production fleet with the goal of increasing operator productivity and safety, and raising dispatcher awareness and control. Amongst the broad productivity goals CNRL wanted to achieve with help from the system was a very specific need to blend ore at the truck level. CNRL uses 25m x 25m block geological model information to represent their complex ore body. Wenco's High Precision GPS application, BenchManager provides precise graphical actual-vs-design operator feedback and system integration. Together the two companies advanced the BenchManager product to meet CNRL's needs by using live camera feeds to compare activity with data collection that ultimately lead to changes in the algorithm to include enhanced GPS indicators and the support of a GLONASS assisted solution generating distance and bearing information.

May 1, 2011

By G. J. Arseneau

ABSTRACT Mineral resource statements are reported as tonnage (volume × density) and grades. Effort is expended to accurately estimate the volume and grade, but accurately determining bulk density is often overlooked. Oversimplification of density modelling can result in potentially serious errors in tonnage estimates and over- or underestimation of metal content. A reliable bulk density model requires an adequate database and a good understanding of density variability, along with grade and geology. In this paper, the author summarizes density measuring techniques, draws on examples of simple and complex grade-variable density domains, and discusses improved approaches for minimizing density estimation errors.

Jan 1, 2014

By François Charette

High stress conditions in weak rock masses lead to large deformation and breakdown of the rock material, while stress release events in hard rock mines can lead to sudden and usually violent rock failure. Typical support systems combine various reinforcement and support mechanisms to provide the required convergence control and retainment, but results are often mitigated by failure of surface liners, shotcrete and tendons. The paper reviews differing requirements of support and reinforcement for different failure types. In addition, the mechanical performance of a new reinforcing tendon is presented and analysed in view of the field requirements. Field tests results are presented.

May 1, 2011

By M. Saghaeian, R. Hejazi, Sheikhzadeh. V., A. Abazarpoor

"The morphology of iron ore concentrate particles is known to influence several properties of iron ore pellets, including drop number, compression strength, and reduction properties. This study aimed to determine why grinding methods and particle morphology influence green pellet properties. Particle morphology can be directly related to the grinding method: ball mill (BM) or high pressure grinding roll (HPGR). In this research, two iron ore concentrates, namely Gol-e-gohar and Ardakan, were ground by a BM and HPGR to produce a suitable Blaine value for pelletizing (nearly 1,900 cm2/g). Morphological features of particles were subsequently investigated by sieving and cyclone sizing for particle size distribution, the Brunauer-Emmett-Teller (BET) and Blaine methods for specific surface area (SSA) and scanning electron microscopy (SEM) for the evaluation of shape descriptors. It was concluded that HPGR resulted in generating a greater proportion of fine particles compared to ball milling. The BET results showed that the SSA of HPGR pellet feed was higher than that from the BM due to a greater proportion of cracks, indents and bulges and the creation of new fracture surfaces. SEM images processed by ImageJ software indicated that particles ground by the BM tended to be more rounded and less elongated than HPGR particles because of the breakage model of each method. To show the effect of morphology on the green pellet quality, green pelletizing was performed in a pilot pelletizing disc. The HPGR pellet feed had a higher drop number in comparison to the BM pellet feed, due to the angular and rough shape of the particles.INTRODUCTIONThe demand for fine or ultra-fine particles as feed material for ceramics, composite materials, and mineral processing is on the rise (Kotake, Kuboki, Kiya, & Kanda, 2011). The final concentrate of iron ore processing plants (filter cake) has a size range roughly between 0 and 300 µm, depending on the liberation of Fe containing particles (Meyer, 1980). In general, to produce a suitable pellet feed of appropriate quality, Blaine numbers of 1800–2000 cm2/g should be achieved (Van der meer, 2015)."

Jan 1, 2016

By X. X. Wu, Q. Zhang, R. H. Fan, Y. J. Feng, J. D. Liu, P. Z. Zhao

In the present study, AA6016 automotive sheets with different grain size were fabricated through changing fabricating parameters, and the effects of grain size on the bendability were studied by bending test and optical microscopy. The results showed that the sheet with coarse grains exhibited poor bendability, and some micro-cracks were revealed at the surface of the bending samples. While the sheet with fine grains exhibited good bendability, and the bending samples showed smooth surface. Shear bands on the cross section of bending samples were observed. It was found that samples with coarse grains had more shear bands. These shear bands distributed in bundles, which facilitated the formation of continuous neckings and micro-cracks. However samples with fine grains had less shear bands, which distributed uniformly. The decrease of grain size could not only hinder the formation of shear bands, but also improve the homogeneity of its distribution during bending. On the other hand, refining grains could increase the amount of grain boundaries, which impede the propagation of shear bands. Hence the decrease of grain size could hinder the formation of continuous neckings and micro-cracks during bending, resulting in the significant improvement of the bendability.

Jan 1, 2015

By Peter J. Franklin

"Short-term mine planning of open pits is an activity that has historically been carried out by hand. Typically, the use of computers has played little part in this type of mine planning. This paper describes the objectives and the procedures involved in short-term mine planning, comments on the type of computer systems available, and describes in detail a computer-aided short-term planning and scheduling system known as STEPS.IntroductionThe mine planning department of any o pen-pit mining operation performs a wide variety of different tasks. However, their primary concern is the preparation of detailed long-and short-term mine plans. These mine plan s will define the long-term operating strategies and definitive everyday working plan s for the ongoing development of the open pit.In this day and age, when operating costs have spiralled upwards due to inflation , and product revenues have decreased due to depressed economies and poor markets, it is vitally important for all aspects of the mining operation, including mine planning, to be efficient and cost effective.There are numerous options available for planning engineers when generating a mine plan. A cost effective mine plan must investigate all these options and select the optimum. When using manual planning techniques, it is often impossible to evaluate all the available options. To do this, and to produce an optimum mine plan, a computer is required.This paper discusses mine planning, with emphasis toward the short-term plan and comments on how the processes may be computerized. It also describes in detail, a computer software system called STEPS, which has been designed as an interactive graphics, computer-aided short -term mine planning and scheduling tool."

Jan 1, 1985

By Janice Zinck

?Past? Images of Mining ?Historic practices have been poor ?Mining still widely perceived as environmental ?spoiler? ?Public only hears the bad news stories. Lessons Learned from the Past ?Sustainability matters ?Recognition of social and environmental responsibilities ?Recognition of importance of public concerns and perceptions ?Community engagement

May 1, 2009

By D. Thibault, A. Akhiate, M. Brochu, E. Braud

Cast martensitic stainless steels, 13%Cr-4%Ni, having carbon contents between 0.018 wt% and 0.067 wt% were normalized, air quenched, and tempered at two different temperatures (550°C and 610°C). Their microstructures were characterized by optical microscopy and X-ray diffraction (XRD). Macro and microhardness, tensile strengths, and impact resistance were quantified for each material and condition. Results show that the prior-austenite grain size is constant through the materials but the percentage of reformed austenite, contained in the martensitic matrix, depends strongly on the material chemistry and on the tempering temperature and on its duration. It is observed that, independently of tempering conditions, an increase in carbon content increases the material hardness and tensile strengths, whereas the elongation remains constant. In contrast, the results of Charpy type impact toughness tests show a different trend. The material containing the average carbon content (0.034 wt%) is significantly tougher than the two other alloys. Surprisingly, the toughness of the steel containing 0.034 wt% carbon was found independent of the reformed austenite content. It is thus concluded that carbon and reformed austenite contents are not the only parameters affecting the toughness of these steels.

Jan 1, 2014

By Mark B. Thorpe

Golden Star Resources started gold mining operations in Africa in 1999 after 15 years of exploration in South America. At the time, the approach to local assistance was through "alternative livelihood" programs and the donation of infrastructure to local communities. This was initially successful with local community support. However, with time and on reviewing the implemented projects, it became evident that the success was limited and many if the projects were either poorly used or in disrepair. Through a review of the options, we decided to develop a community assistance model driven by the communities themselves, while keeping control of the finances and the actual construction of the projects. Through the formation of the Golden Star Development Foundation, we began to support community driven projects for local economic development. The evolution of economic development projects continued over the next several years with the addition of project requirements for partnerships with government, and finally an evolution to a partnered turn-key piece of infrastructure that we hand over to an agency for operation and ongoing maintenance. We are currently working with outside partners to further our economic development activities in Ghana to the benefit of our stakeholders.

May 1, 2011

By Joseph Carlston

With environmental regulations continuing to restrict the discharge of phosphorus from wastewater treatment facilities, traditional methods of phosphorus removal are proving inadequate. To achieve the phosphorus control necessary, a new coagulant used for phosphorus removal, cerium chloride, has been studied in several municipal and industrial wastewater treatment facilities that must meet a phosphorus discharge limit of 0.5 mg/L or lower. These studies demonstrated the high phosphorus removal capabilities of cerium chloride, with the results illustrating the ability for cerium chloride to reduce phosphorus to low concentrations in the effluent using a lower volume of product as compared to traditional coagulants, such as ferric chloride. This reduction is due to the unique ability of cerium chloride to remove phosphorus as cerium phosphate, whereas iron- and aluminum-based coagulants rely on adsorption and co-precipitation.

Jan 1, 2014

By R. S. Boorman, L. J. Surges

"Ore reserves at Brunswick Mining and Smelting totalled 101(106) tonnes grading 97 grams tonne-1 silver at the end of 1981. Silver is recovered as a byproduct in the copper, lead and bulk concentrates and is lost to the zinc concentrate and plant tailings. Recovery of silver for the year 1981 was 58,5%. The loss of potential revenue is in excess of Cdn $50(106) year-1 at current silver prices and milling rates.Silver is known to occur in solid solution in galena and as tetrshedrite. Evidence indicating the identity and significance of a third silverbearing mineral assemblage is reviewed and the distribution of silver losses is detailed. Characteristics of each the carrier which may be responsible for observed distribution, including size, surface quality, liberation and composition are considered, and the third carrier is shown to have possible implications for improved silver recovery by other Canadian producers as well as by Brunswick Mining.Silver tetrahedrite tailings distributed tailings and losses occur as coarse, free and as very fine unliberated galena in losses of the third carrier are between the zinc concentrate and are concentrated in the finest size fractions. Process alternatives for enhanced silver recovery by physical and chemical means are reviewed."

Jan 1, 1983

By Yuki Tsunazawa, Shuji Owada, Sho Fukui, Chiharu Tokoro

"Since the amount of e-waste has been rapidly increasing all over the world, there is a desire to develop the effective recycling process. E-waste has various kinds of electronic components with valuable and/or hazardous materials. Recycling of them is an important subject from the viewpoint of both the recovery of valuable materials and waste treatment. In common with all mineral processing, the comminution of e-waste is a key process because the liberation states after comminution determine the overall efficiency of metal recovery. Since some of useful critical metals are concentrated in a specific component, a special and selective grinding is expected to be effective. However, the knowledge about the mechanism and the effectiveness of the selective grinding is still limited and unclear.To better comprehend the mechanism, in this study, the investigation of comminution process using the particle-based simulation was conducted. Especially, this study focused on the comminution performance of printed circuit boards (PCBs), which are major components of e-waste. The behavior of PCBs and airflow in a drum typed agitation mill having flexible chains was simulated by the discrete element method (DEM) coupled with computational fluid dynamics (CFD). To model the shape of PCBs, the particle based rigid body model was introduced into the DEM. Since this model could not directly simulate the breakage phenomena, collision energy was calculated to qualitatively evaluate the comminution performance. In addition, the simulation results were compared with the experimental comminution tests using simulant PCBs where some capacitors were solder-mounted. These results indicated that comminution performance was affected by the rotation speed of the agitator. It was also demonstrated that the comminution performance was qualitatively evaluated using the particle-based simulation and this particle-based simulation made it possible to investigate the mechanism of e-waste comminution."

Jan 1, 2016

By C. Mills, A. O. Burt

"The paper examines the role of gravity concentration in both an historical context and within the modern mineral processing industry. It discusses the principles of the process on both a theoretical and practical level. The importance of more mineralogy and its effect on the choice of the wide range of equipment available is discussed. The paper concludes with a discussion on the relative merits of gravity concentration with other forms of processing.IntroductionIt is an unfortunate, albeit popular, misconception among otherwise enlightened engineers in the mineral processing industry that gravity concentration was a process developed in the dark ages, perfected in the middle ages, and abandoned in the modern ages.Gravity concentration was developed in the dark ages - long indeed before that. Agricolau: cited examples of gravity concentration, crude examples admittedly, being practiced over 3000 years ago. However, gravity concentration is not dead. Far from it. As recently as 1978 it was reported that the total mineral tonnage treated by this process in the United States was greater than that processed by flotation. Coal represents the bulk of the or e treated by gravity separation in the U.S.A., with iron ore representing a major portion of the balance."

Jan 1, 1985

By M. Fiset, D. Belley

"To better understand the wear process of various materials that may be used as blades on snow removal equipment, the first step is to evaluate the influence of the load applied and the moving speed on road wear rates of one type of steel and three types of polymers. While the behavior of steel conforms to Archard's law, wear rates of polymers increase to a power of ex of the load applied according to a model implying that the wear of these materials is due to fatigue. The wear rate of some of the polymers varies considerably in terms of speed, unlike the steel. The wear resistance of some of these polymers outclasses the steel tested as long as the speed is not too great. They, therefore, present interesting alternatives for snow removal on more fragile surfaces such as sidewalks and zone made of inter-block slabs.IntroductionSince the dawn of the Industrial Revolution, the massive use of machines has brought with it a number of different problems regarding wear. Snowplowing roads, parking lots and sidewalks is an activity that generates enormous expense in a country such as Canada. To better understand these wear processes and in the hope of stimulating new approaches designed to reduce the costs related to this sector of activity, this paper presents the behaviour of several materials (steel, polymer and rubber) as they wear on an asphalt-fines matrix surface lubricated with water. Also discussed is the effect of various parameters such as the load applied and speed."

Jan 1, 1990

By S. Dessureault, M. Yildirim

More mining companies are now investing in IT, including updating one of the traditional IT process control tools used in the mining industry: real time in-pit truck allocation control and monitoring systems, or fleet management systems (FMS). These systems have been used to maximize the overall mine production by improving equipment utilization and reducing production costs. Most modern operations monitor the in-pit operations using GPS and wireless communications to produce data. Improvements in bandwidth, sensors, and computing power are causing modern systems to become more complex and generate more data. However, human analysis by simple regression or table generation in spreadsheets of the data is becoming impossible. Data mining solves this data management problem. Data mining finds patterns and relationships in very large data sets. This paper describes the application of modern data mining techniques on truck dispatching systems in a real open pit hard-rock copper mine. The analyses conducted included determining how the trucks performed under particular conditions and allocation systems. The long-term benefits of this work are to identify strengths and improvement opportunities in truck assignment systems and establish the skill sets and IT infrastructure needed in undertaking more complex datadriven technology such as a truck dispatcher trainer.

Jan 1, 2007

By R. Prioul, J. Kear, D. Chuprakov, A. P. Bunger

"Hydraulic fracture (HF) growth through naturally fractured rocks challenges the development of accurate predictive HF models. The authors present laboratory experiments differentiating behaviours associated with orthogonal and oblique intersections between HFs and natural fractures (NFs). HFs were created in sandstone and crystalline (gabbro) rock specimens, impinging orthogonally or obliquely on an unbonded machined frictional interface. Ultrasound monitoring was used to observe the rate of propagation through the interface. A contrast was observed between direct and offset crossing for orthogonal and oblique intersection, respectively. The stresses required to promote crossing depended on the intersection angle between HFs and NFs.RÉSUMÉ La propagation des fractures hydrauliques (FH) dans les roches naturellement fracturées pose un défi pour le développement de modèles prédictifs. Nous présentons des essais en laboratoire qui différencient les comportements associés aux intersections orthogonales et obliques entre les FH et les fractures naturelles. Des FH ont été créées dans des spécimens de grès et de roches cristallines (gabbro), heurtés de manière orthogonale ou oblique sur une interface machinée, non liée, de frottement. Un suivi par ultrasons a servi à observer le taux de propagation à travers l’interface. Un contraste a été observé entre un croisement direct et un croisement indirect des intersections respectivement orthogonales et obliques. Les contraintes requises pour promouvoir le croisement variaient selon l’angle d’intersection entre les FH et les fractures naturelles."

Jan 1, 2016

By Brendan Parker, Tyron Rees, Steven Hart, Abba Manesh, Ian Mcgaffin

"In September 2009, Newmont began the commissioning of a 3 stage crushing and milling circuit at its Boddington Gold Operation in Western Australia. The Boddington ore has been recognized as one of the hardest and most abrasive ores treated to date and this played a pivotal role in the selection of crushing and HPGR technology for this operation as opposed to the more conventional SABC circuit.This paper will examine the scale up from laboratory to pilot plant and full scale operation of the crushing circuit. There have been many challenges to overcome in the first 18 months of operation; however, the HPGRs have in general met design expectations and performance is expected to improve further with ongoing design changes"

Jan 1, 2012

By B. Kruger

The Dundee Precious Metals Tsumeb Smelter has evolved over the last decade to meet the challenges and opportunities brought about by a changing copper concentrate market, technological advances, environmental legislation as well as social and political changes. The paper discusses some of the challenges, successes and lessons learnt through the expansion and modernization of its smelter complex. It considers the details and impact of the transition from slag granulation to that of slag slow cooling as well as the improvement program that was implemented to more than double the refractory campaign life of the Ausmelt furnace from around 6–9 months to 15–18 months. In addition, given the evolving world we live in, it considers the challenges that the smelter faces today, not the least of it being how to remain relevant in an age of digital and other 4th Industrial Revolution disruptions. INTRODUCTION Dundee Precious Metals Tsumeb (DPMT) Smelter is located just outside the town of Tsumeb, in the Oshikoto region of Namibia. It is the largest town in the region with a population of approximately 45,000. The smelter was built in the early 1960s to treat concentrate from the nearby Tsumeb copper mines. Construction of the site was completed in 1962 and the smelter was officially commissioned in 1963 by Tsumeb Corporation Limited (TCL). At the time the smelter consisted of a lead section (including a refinery), a copper section and plants that produced cadmium, sodium antimonite and arsenic trioxide. Production commenced in early 1964, with 3,500 tonnes of copper and 6,000 tonnes of lead being produced per month. TCL was acquired by Gold Fields South Africa in 1988, and a few years later the lead section was shut down due to reduced lead content of the mined ore. In mid-1996, all mining and smelting operations were halted due to labour strikes. Ongopolo Mining and Processing Limited (OMPL) re-opened the mines and the smelter in 2000, only operating the copper section of the smelter. At the end of 2008, all mining operations were halted by the new owner of OMPL, Weatherly Mining International, while the smelter continued to operate. The closure of the Weatherly owned mines in Namibia, the primary feed source to the Tsumeb Smelter, meant that the smelter had to transition its business model from operating as a ‘captive smelter’ to that of a ‘toll smelter’. Its Ausmelt Top Submerged Lance (TSL) smelting technology and various ancillary plants made it especially suitable for accepting and treating complex concentrates that were available on the global market.

Jan 1, 2019

By A. K. Alzo?ubi

Block toppling in natural rock slopes has been under investigation since the 1970?s. De Freitas and Watters (1973) introduced the term ?toppling? to describe the movements of rock slopes by rotation in steeply dipping beds. The Lornex pit case history from British Columbia (Canada) was chosen to study the effect of mining on the stability of toppling rock slopes. A discrete element approach that allows fracturing of intact material was applied successfully to model the composite rock slide-rock topple movement. Three main movement modes were observed in the field and the numerical model; the sliding of the top of the slope exposed normal scarps, the toppling at the middle part of the slope exposed obsequent scarps facing opposite to the slope face, and dilation of the rock caused by fracturing at the toe formed loose material. The development of the rupture surface at the toe of the slope was traced and did not evolve into a continuous rupture surface throughout the slope both in the field and the numerical simulation. Good agreement was achieved between the deformations recorded in the field and the numerical simulation.

Jun 1, 2012