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By S. Setayeshgar

The identification of potential accidents on construction sites has been a major concern in the construction industry and it needs a proactive safety plan to reduce the risk of accidents. There are no efficient methods for checking if safety measures are taken properly on construction sites. Consequently, workers on site are not given enough awareness about dangerous areas. In addition, construction sites are dynamic and on-site situations are changing in terms of permanent and temporary structures and facilities. This information can be represented using Building Information Modeling (BIM). This paper proposes the integration of BIM and safety risk analysis by considering the risk levels associated with the work spaces of different construction tasks. Work spaces are generated in a BIM model according to the Work Breakdown Structure (WBS) of the project, reference objects in the BIM, and the schedule and resources of the task. Each work space is assigned to one or more tasks or functions, e.g., work spaces for specific tasks, shared spaces (paths), storage spaces, or spaces prohibited to workers. The assignment of work spaces is based on the workers, equipment and materials involved in the task. All the work spaces are associated with a specific duration according to the schedule of the project. Then risk evaluation of the construction site is applied in order to evaluate safety risks based on their severity and the degree of exposure of workers. For example, work spaces for storing hazard materials and for heavy construction equipment have higher risks than other work spaces. The results of the risk evaluation can be visualized in a 4D BIM model.

Aug 1, 2013

By L. A. Ayres da Silva, J. P. G. Negri, A. L. M. Ayres da Silva

"Rock hardness is dependent on the type and quantity of the various mineral constituents of the rock and the bond strength that exists between the mineral grains. As the book “The Complete ISRM Suggested Methods For Rock Characterization, Testing and Monitoring:1974-2006” explains, hardness is a concept of material property. As such, the quantitative measure of hardness depends on the type of the test employed.Among the three types of tests that have been used to measure the hardness of rocks and minerals: 1) indentation tests; 2) dynamic and rebound tests; 3) scratch tests, the authors of this paper chose indentation tests, more specifically the Vickers test, and complementary verified the correlation between the results of the Schmidt sclerometer tests (rebound tests) and the Vickers microhardness tests in a set of the same 9 (nine) granite rocks.The objective of this research was to verif y the correlation of one created index, based on the Vickers test that can be able to represent the rock material hardness. We know that Vickers tests determine the microhardness of individual rock minerals. A pyramidal shaped diamond is applied to the surface with a specified force. The area of the permanent residual deformation divided by the applied force is a measure of the hardness. Using the relative participation of the mineral components of the rock, we established a hardness index denominated EVM (Equivalent Vickers Microhardness).The correlation of the EVM with others strength properties and application parameters like UCS (Uniaxial Compressive Strength) to study sawability of granite blocks have presented very good results. The association of equivalent microhardness with others strength parameters, allowed to find powerful algorithms for analyzes of the rock materials behavior under diversified circumstances, as the sawability of granite blocks, as we can see in Fig. 1.Other very interesting correlations were found as the EVM values and that were obtained by the use of the Schmidt impact hammer for the superficial hardness determination."

Jan 1, 2015

By N. Bakhshizadeh

In this investigation, the aging effect on creep behavior of A12024-10%SiC composite fabricated by powder metallurgy was studied. P/M bars were manufactured by hot powder extrusion method at 450°C with a ratio of 16 to 1. Creep specimens were over-aged at 187 ºC for 43 h. It was found that almost full density composite with relatively homogenous distribution of reinforcing particles throughout the aluminum alloy matrix could be attained by direct powder extrusion process. Creep tests were conducted at temperatures from 275 to 325°C under stresses from 25 to 60 MPa. The analysis of the creep mechanism determined that dislocation glide was the predominant mechanism of plastic deformation. The activation energy of the creep process was found to be higher than that of lattice self-diffusion in pure aluminum.

Jan 1, 2007

By The Honourable George Prudham

"I AM PLEASED indeed to be present with you here today and to be taking part in the proceedings of your convention. You have been greeted and welcomed to the Province by Premier Manning who is also provincial Minister of Mines and Minerals, and to this City by Mayor Hawrelak. As Minister of Mines and Technical Surveys in the federal government and as Member of Parliament for Edmonton West, I have been asked to share the honour of extending greetings and a cordial welcome to all.It is a happy coincidence that this representative national gathering, indicative of the growing strength and significance of a great basic Canadian industry, is taking place in the Macdonald Hotel, the new addition of which marks another important step forward in the progress of this City and district.This happens to be the third national convention of the C.I.M. that I •have had the pleasure of attending and I trust that I am not presumptuous in expressing the hope that I will have the opportunity of attending many more conventions of the Institute in my present capacity.Dr. Kidd has bestowed on me a high honour by asking me to be Co-Chairman of this Inaugural Session of the Convention and thus to share with him the responsibility of presiding over the proceedings of this afternoon."

Jan 1, 1953

By Simon Weixiao Sun

Conventionally, carbon steel has been the primary material for salt mine headframe construction, protected by specialty paint layers to prevent corrosion. These layers require meticulous QA/QC during fabrication and erection, and the top UV protection layer typically loses effectiveness after an average of 10 years, necessitating ongoing maintenance. As headframes age, significant structural repairs are often required. Alternatively, stainless steel can eliminate corrosion concerns, though its high initial cost has limited its use in headframe design. However, when factoring in long-term maintenance costs, a 'maintenance-free' stainless steel headframe can be an attractive option for stakeholders. This paper compares the structural performance and economic considerations of painted carbon steel and stainless steel headframes, including initial capital and long-term maintenance costs. Additionally, it explores a hybrid approach, strategically using carbon steel in low-contamination areas to reduce initial costs and significantly minimize future maintenance efforts.

May 4, 2025

By V I. McCallum

In 1954, Falconbridge Nickel Mines Limited began the program of deepening the Falconbridge mine workings for 2,000 feet below the bottom, or 4025, level in order to provide twelve new levels for production. Involved in this program were a production-sized internal shaft, .crushing, pumping and hoisting installations, the integration of the new shaft operations with those of existing shafts, and considerations of ventilation requirements and ground support at depth. This paper describes the major items of equipment, and the depth development of No. 9 shaft as a whole, and also emphasize the planning phases of the program. The factors involved and reasons for the equipment and layouts chosen are given. Introduction and History THIS paper describes the planning and development of that portion of the Falconbridge mine between the 4025 and 6050 mining levels. This mine, the oldest of several being operated by Falcon-bridge Nickel Mines Limited in the Sudbury district, has been a continuous producer for over thirty years.

Jan 1, 1964

By T. Fliß

The protection of natural resources is of essential importance in times of rapidly increasing populations and resulting shortage of agricultural land. Soil and groundwater resources play a central role for the production of food or feed of any kind. The intensive agricultural and environmentally friendly use of these resources must ensure sufficient income and sustainability of life for future generations. Mining projects often represent a particularly deep intervention into ecosystems due to their size as well as the most expensive treatment processes. Conventional mines comprising of shafts and developed mining fields require the stockpiling of waste rock and in particular to potash mining, the discharge of brines from raw salt processing. In contrast, mining operations based on the solution mining method can be operated without major environmental impacts and lower security risks. While the solution mining for the production of rock salt finds application since more than 500 years, exist a procedure to produce potash using solution mining only since the 1980's. For solution mining drill holes are used to exploit the potash, launched from the surface into the deposit. The exploitation of the raw material occurs by the dissolution of the potash injecting solvents and creating so-called brine caverns. Currently, a number of mining projects in Carnallite deposits by the solution mining method are in progress around the world. Often these projects are located in sensitive ecosystems. K-UTEC project and support actual a solution mining operation of a Carnallite deposit for a Chinese customer in South-East Asia. This work comprises a comprehensive geological and geomechanical modeling as well as stability analyses. Furthermore the cavern design and brine field layout as well as the planning of the brine processing and the plant design. The present paper introduces this project as a case study. The application of a special solution mining procedure and processing design ensures an emission-free mining operation (Zero Disposal Plant). The emission-free operation is achieved by utilizing the full extent of the caverns to dispose the liquid solutions from processing. The presentation of principal salt processing and technical equipment will be rounded by information about the geology of the deposit. Since the deposit includes a number of sensitive minerals, such as Tachyhydrite and Bischofite the presentation comprise a lot of interesting items with special view at the brine field operation. K-UTEC designed and delivered a special blanket measuring system and a well cement according the request of the customer. K-UTEC, a research and engineering company with more than 60 years of experience in the sector of potash and rock salt mining, developed the world's first solution mining operation for Carnallite in Germany more than 30 years ago. In recent times K-UTEC served in different solution mining projects worldwide, with special view at the environmental impact, as well as the optimal utilization of the deposits.

Aug 1, 2013

By Brian Hall

For some years, the mining industry has been consistently delivering returns below the market average. One of the causes is a disconnect between what is perceived to drive value creation by many industry analysts and senior corporate executives, and what actually drives the intrinsic value of mining operations. The perverse effect is that strategies that should increase value are perceived to have the potential to drive share prices down, and vice versa. This paper challenges common perceptions of what drives a mining company?s value. Anecdotal evidence suggests that the key drivers of value in the market, and hence in many boardrooms, are such things as increasing the reserves and production rate, and reducing unit operating cost. However, while the quoted reserves may satisfy ore reserves reporting code requirements to be economic, this does not imply that they are optimal. Often, a proportion of the quoted reserve reduces the potential value of the operation. Metal price increases, increased production rates, and operating cost reductions are all seen as conditions or actions that can improve value, and lead to cutoff grade reductions, thereby increasing ore reserves. However, modern cutoff theory and studies conducted by the author and his colleagues show clearly that, while breakeven cutoff grades will fall in these circumstances, optimum cutoffs may be much less volatile, and may even increase. Results from case studies indicate that value is maximised by right-sizing, not maximising, the production capacities, and by optimising the cutoff strategy. Values of many existing underground mining operations can be increased significantly by a substantial cutoff grade increase. Also, an increase in downside risk, and hence reduced returns, can occur using typical life-of-mine planning strategies if prices received are lower than predicted. Since this is often the case, low industry returns may be a direct result of typical strategic mine planning processes. Relatively simple cost-effective techniques are available to provide senior decision makers with information needed to assess the tradeoffs between their many conflicting corporate goals, and the balance between risk and reward. Often this information is not being generated at all. If it is, decisions affecting the value of the company are occurring by default at relatively low levels within the hierarchy, with senior executives apparently unaware of them or their potential impact. The paper concludes that without a re-evaluation of the way mining projects are valued, to demand proven value optimisation from mining plans by boards and mining analysts, the industry will continue to deliver below average returns.

May 1, 2003

By T. A. Lazier, C. S. Longley

"Paymaster Consolidated Mines, Limited, owns several groups of claims in various parts of the Porcupine district. The area in which mining has been carried on includes parts of lots 5, 6, and 7, con. 1, Tisdale township, and twelve adjoining claims in Deloro township to the south. Highway No. 67A between South Porcupine and Timmins crosses the property.The discovery of the Dome mine in 1909 caused a rush of prospectors to the district and in a few weeks practically all territory adjacent to the Dome was staked. At that time work was started on the West Dome, West Dome Lake, Apex, and Standard properties. These were consolidated in 1930 to form the present Company. Gold was produced from the West Dome Lake from 1915 to 1930, and from the Standard-Paymaster from 1922 to 1928. The total production of the previous and present companies from 1915 to November 30, 1946, has been 487,170 oz. gold and 149,342 oz. silver from 2,337,554 tons of ore."

Jan 1, 1954

By John C. Luck Jr.

"DEVELOPMENT of oil emulsion mud dates back to the early days of rotary drilling when oil was added to the drilling mud solely for the purpose of freeing stuck drill pipe. After the drill pipe was freed, and drilling resumed, this oil was considered a contaminant. Efforts were made to remove the oil but some of it remained and was emulsified with the drilling mud, thus forming a mechanical emulsion.During the late 1930's, operators found that adding crude oil to drilling muds seemed to alleviate 'sticky-hole' problems and so oil was allowed to remain in the mud. This practice was adopted when it was found that faster drilling rates and longer bit life were obtained. These observations led to the development of emulsion drilling muds. During the past five years their application has become more widespread because of the lower fluid losses obtained, greater lubrication qualities, faster penetration rates, and generally better hole conditions.An emulsion may be defined as a two-phase system consisting of a mixture of either finely divided oil droplets in water or of finely divided water droplets in oil. The surrounding liquid is known as the continuous phase. The emulsifiers reduce the interfacial tension, making the droplets tend to repel each other so that they remain dispersed and stabilized. These emulsions are classified as oil-in-water or as water-in-oil, depending upon whether water or oil, respectively, is the continuous phase. Briefly, close inspection shows that they consist essentially of globules of• the one liquid suspended in a continuous mass of the other liquid. Oil emulsion muds are usually of the oil-in-water type. Two basic types of emulsifiers •commonly used in Canadian muds are soaps and lignites."

Jan 1, 1954

By P. D. R. Maltby

This paper describes the background and markets for calcium carbonate and silica sand in Canada, as well as the results of recent test work carried out at the Ontario Research Foundation. Tests on sericite, tremolite, vermiculite, barite and graphite are also mentioned.

Jan 1, 1979

By H. R. Manouchehri

"It is well understood that, apart from particle hydrophobicity, the flotation process is strongly influenced by the cell hydrodynamics. Once the chemical conditions were optimized and fixed, the flotation rate is essentially determined by impeller speed and the air flow rate.The collection efficiency in flotation is a product of collision, attachment and stability/detachment efficiencies. The collision efficiency for a given particle diameter is increased by decreasing the bubble size and bubble velocity as well as increasing the power input to the cell. The attachment efficiency, however, is defined by bubble size and its velocity. The detachment/stability depends on the relative magnitudes of the attachment force between the bubble and particles and the detachment force acting on the bubble-particle aggregates. For the particles having specific contact angle, the stability decreases as the energy input increases. Therefore, there must be an optimum energy dissipation to maximize recover of defined size fraction.A comprehensive laboratory study was devoted to determine the effect of power input in recovery of finely grind Cu-Ni bearing ore. Several flotation tests were conducted to define the hydrodynamic parameters for a laboratory scale Runge cell under different impeller speeds. An increase in flotation recovery of finely ground ore was observed when the impeller speed was increased from 450 to 1,200 rpm. The experimental results have shown increasing in water recovery and improving in flotation kinetics of fines by increasing the power input to the flotation cell. Implementation of the Wark flotation model to the experimental data revealed a good correlation between the experimental data and the model. For the particles having enough hydrophobicity the flotation rate increases by increasing the impeller speed due to a higher value for collision efficiency within the cell."

Jan 1, 2016

By H. D. Stolovitch, M. L. Lavallée

"An engineering system used to analyze and improve the performance of industrial grinding circuits has been adapted into a training program. The systematic approach to the design of training was applied in order to:Determine if training was an appropriate and effective tool for the transfer of this new technology;Define the technical content of the program;Establish program specifications based on learner and context characteristics;Design and test prototypes of the instructional modules; and,Establish a strategy for plant implementation and maintenance of the training program.This paper thus describes how a engineering system is transferred to the workplace through the use of designed instruction.INTRODUCTIONTraining can change human performance in a permanent way. It can improve productivity for the overall benefit of an operation. Organizations can therefore use training as a mean to achieve their specific goals. Training is not the solution to every performance problem. However, in many cases, it can be a very effective way to attain desired performance.The benefits of training are often difficult to assess. However, to remain competitive, organizations must introduce new products and innovative technologies. Often, they can do both most effectively through suitable training interventions.In order for the effort and investment of training to provide optimal results, two points of view should be adopted.• An overall view of the system in which training is to be applied.• A systematic approach to the design of training (Stolovitch and Keeps, 1989)."

Jan 1, 1992

By G. Lodewijks

This paper explores the savings that can be achieved in the energy consumption of belt conveyors used in mines by changing the conveyor components, the operational parameters of the system or the belt properties. First the concept of energy savings is introduced by looking at the energy consumption of belt conveyors from a theoretical point of view. Also methods for the calculation of the power consumption of a belt conveyor and the associated emissions are presented. Two case studies are presented in which the effects of the change of the operational parameters of the system, in this case the belt speed, and the belt properties, in this case the application of aramid products in the belt, are presented.

Aug 1, 2013

By Fazel G. Jahromi, Ahmad Ghahremaninezhad

Enargite (Cu3AsS4) is a major complex copper mineral and often is a carrier of invisible gold particles. Pyrometallurgical treatment of enargite is challenging due to the arsenic release to the environment. Hydrometallurgical treatment, on the other hand, appears to be a promising alternative for enargite processing. In an atmospheric enargite leaching process both the copper and arsenic from the mineral can be leached into a sulphuric acid solution and the arsenic can be simultaneously precipitated as ferric arsenate. The unlocked gold in the residue then can be recovered in a subsequent cyanidation circuit. The downside of the atmospheric enargite leaching in sulphate solutions is the slow leaching kinetics. In this study the effective parameters of the atmospheric enargite leaching process in ferric chloride media were investigated. All the experiments were carried out at temperatures below 100 °C. The process parameters that were investigated in this study included ferric, chloride, sulphate and cuprous concentrations, temperature, mixing rate and leaching slurry pulp density. It was found that the copper recovery rate increases with the addition of cupric chloride and also with raising the temperature. The highest leaching kinetics and the highest overall copper recoveries were achieved when cupric was initially added to the leach solution and at 90 ºC.

Jan 1, 2015

By B. Arlyuk

The complex system has been developed for long-term assessment of world prices and sale volume of primary aluminium when using the analytical model of the market and market supply forecasts as well as economy development in the Western countries characterized by the industrial production indices as correct data of Western World aluminium consumption are absent, The important part of this system is the model developed for forecasting the degree of capacities utilization of smelters and refineries depending on the price level, The model contains a statistic part corresponding to the capacities distribution by the production cost, and a dynamic part determining the deviation from the static depending on the price variation dynamics, The developed complex system has been identified by the actual data of the world prices of smelter grade alumina and primary aluminium, conservation and reactivation of refineries and smelters in the Western countries within the period from 1992 to 2003. The system was used for primary aluminium and alumina price forecasts till 2020.

Jan 1, 2004

By Jochen Franke, Derek D. Lichti

"This paper gives a brief introduction and presents recent enhancements in the MillMapper technology developed for thickness gauging and condition monitoring of liners in grinding mills used for mineral comminution. It also introduces the recent expansion of MillMapper functionality aimed at mill operational optimization. MillMapper uses calibrated laser scanner data captured inside a mill to determine thickness at several million points on all liner surfaces at feed, shell, and discharge ends with millimeter accuracy. Data capture takes nominally 5 minutes, hence interruption to mill operation is negligible.The paper is structured as follows. First, a review of the technology and discussion of recentlyimplemented innovations such as liner change out forecasting, automatic ball charge volume and weight measurement, and automatic mill liner volume/weight measurement for mill operational control or load cell calibration are presented. Combined weight information provides control over load related issues such as load fill levels for relining, or start-up load after reline. Feature descriptions are followed by a listing of the numerous advantages over existing techniques and the benefits to operations. Results from the application of MillMapper are presented throughout.INTRODUCTIONThe need for thickness gauging of liners of grinding mills used for mineral comminution is well known but the task is rarely completed to a satisfactory standard. Liner failure resulting from excessive wear can have expensive consequences. Furthermore, mill performance as well as liner wear are known to be correlated to lifter bar geometry (Napier-Munn et al., 1999; Rajamanni et al., 2005). At present, the following techniques are routinely used to gauge the thickness of mill liners:1. Visual inspection;2. Ultrasonic thickness gauging (for steel liners); and3. Physical inspection (e.g. nail inserted in rubber liners)"

Jan 1, 2008

By J. M. Simard, S. Morissette, P. Coursol, P. Mackey

A new, powerful model is presented that focuses on plant logistics and scheduling aspects of the smelting, converting, fire refining and casting operations at the Horne smelter. This plant complex is the largest custom copper smelter in North America. It handles a wide range of feeds and utilizes a number of proprietary continuous and batch technologies that require good scheduling in order to maximize plant capacity and efficiency. The present model was developed by Xstrata Process Support, in collaboration with the Horne smelter, and uses the Arena® software to evaluate the impact of a number of plant variables on the annual copper capacity of the plant. Model development was carried out by Xstrata Process Support, in collaboration with the Horne smelter, through the effective combination of process chemistry knowledge and detailed knowledge of the plant operation (including all material flows and transfers, as well as information such as operating on-line times, plant stoppages and also scheduled and unscheduled maintenance activities). A number of case studies were then examined, including the impact of anode furnace and casting cycle times on annual copper capacity and the impact of a one-crane mode of operation in the converter aisle, which normally operates with two cranes in service. The model predictions were found to match actual plant results very well. The present modelling of plant logistics and the scheduling aspects were found to add important dimensions at the plant with regard to projections of the real-life plant capacity. As demonstrated in the present case, this type of model and application can have a significant impact on optimizing operations at a given plant. This impact is particularly important in the current market environment, where emphasis is on maximizing plant output and lowering costs. These models can help yield the easily obtained gains that are clearly desirable in these times. Xstrata Process Support has developed Arena models for other operations and is available to explore new applications for a win-win situation at other plants, including mines and concentrator operations.

Jan 1, 2009

By Walter F. Atkins

Fair market value, in the legal sense , is the price which a prudent and knowledgeable buyer and a prudent and knowledgeable seller, acting without constraint or compulsion , will agree upon to exchange an asset. In the ordinary commercial or engineering usage, the term may imply simply the market value or a reasonable and equitable price. The engineer evaluator who is called upon to express an opinion about the fair market value of an asset may be able to base his estimate on the sale price of similar assets or on the market values of stock. Frequently such indicators of value are not available and the evaluator must devise other means of appraisal. Mineral resource properties may be thought of as having value by virtue of the existing or potential ability to produce at a profit. Conventional procedures permit the computation of the present value of future revenues having due regard for the time value of money and the risks attendant upon the realization of the venture. Such computations have gained wide acceptance as a basis for the estimation of fair market value.

Jan 1, 1977

"This paper describes an alternative method of vehicle control which uses a micro-processor to control the field current and armature voltage concurrently. The field tests carried out and the conclusions drawn from the basis of the paper.IntroductionIt is generally accepted that the main obstacle to a greater use of electric vehicles is the relatively poor range and performance when compared to alternatives such as diesel and petrol-engine vehicles. Much effort has been applied to the problem of increasing the energy storage density of batteries and considerable improvements are now being reported.Improvements in the efficient use of the stored energy, although unlikely to achieve the necessary increase in range and performance for a widespread acceptance of electric vehicles, can nevertheless make a useful contribution. Because the improvement in efficiency is achieved by a reduction in losses, it follows that the temperature rise in drive-train components is reduced. These advantages, coupled with the increasing cost of energy, make improvements in the efficient use of the stored energy desirable, if not absolutely necessary. To achieve this with the large and rapidly varying loads encountered during the operational use of a vehicle will require a more flexible system of control than that provided by the current limit. This paper describes an alternative method of control which uses a micro-processor to control the field current and armature voltage concurrently.The value of these parameters is selected to supply the power demand at the motor shaft, with the minimum losses in electrical transmission, thus increasing the efficiency with which the stored energy is used."

Jan 1, 1982